Alphatec (ATEC) 10-K 5 Mar 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Mar. 01, 2021	Jun. 30, 2020
Cover [Abstract]
Entity Registrant Name	ALPHATEC HOLDINGS, INC.
Entity Central Index Key	0001350653
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-K
Trading Symbol	ATEC
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	FY
Amendment Flag	false
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Common Stock, Shares Outstanding		95,149,633
Entity Public Float			$ 208.5
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Shell Company	false
ICFR Auditor Attestation Flag	true
Entity File Number	000-52024
Entity Tax Identification Number	20-2463898
Entity Address, Address Line One	1950 Camino Vida Roble
Entity Address, City or Town	Carlsbad
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92008
City Area Code	760
Local Phone Number	431-9286
Document Annual Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE The following documents (or parts thereof) are incorporated by reference into the following parts of this Form 10-K: Certain information required in Part III of this Annual Report on Form 10-K is incorporated from the Registrant’s Proxy Statement for the 2021 Annual Meeting of Stockholders.

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash	$ 107,765	$ 47,113
Accounts receivable, net	23,527	16,150
Inventories, net	46,001	34,854
Prepaid expenses and other current assets	5,439	9,880
Withholding tax receivable from officer	1,076
Current assets of discontinued operations	352	321
Total current assets	184,160	108,318
Property and equipment, net	36,670	19,722
Right-of-use asset	1,177	1,860
Goodwill	13,897	13,897
Intangibles assets, net	24,720	25,605
Other assets	541	493
Noncurrent assets of discontinued operations	58	53
Total assets	261,223	169,948
Current liabilities:
Accounts payable	17,599	7,772
Accrued expenses	35,231	26,416
Current portion of long-term debt	4,200	489
Current portion of operating lease liability	885	1,314
Current liabilities of discontinued operations	397	399
Total current liabilities	58,312	36,390
Long-term debt, less current portion	38,034	53,448
Operating lease liability, less current portion	41	925
Other long-term liabilities	11,353	11,951
Redeemable preferred stock, $0.0001 par value; 20,000 shares authorized at December 31, 2020 and 2019; 3,319 shares issued and outstanding at December 31, 2020 and 2019	23,603	23,603
Commitments and contingencies
Stockholders’ equity:
Common stock, $0.0001 par value; 200,000 authorized; 82,294 shares issued and 82,104 outstanding at December 31, 2020, net of 190 unvested shares and 61,718 shares issued and 61,400 shares outstanding, net of 318 unvested shares at December 31, 2019	8	6
Treasury stock, 2 shares, at cost	(97)	(97)
Additional paid-in capital	770,764	606,558
Shareholder note receivable	(4,000)	(5,000)
Accumulated other comprehensive income	1,204	1,088
Accumulated deficit	(637,999)	(558,924)
Total stockholders’ equity	129,880	43,631
Total liabilities and stockholders’ equity	261,223	169,948
Series A Convertible Preferred Stock
Stockholders’ equity:
Convertible preferred stock
Series B Convertible Preferred Stock
Stockholders’ equity:
Convertible preferred stock

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Redeemable preferred stock, par value (dollars per share)	$ 0.0001	$ 0.0001
Redeemable preferred stock, shares authorized	20,000,000	20,000,000
Redeemable preferred stock, shares issued	3,319,000	3,319,000
Redeemable preferred stock, shares outstanding	3,319,000	3,319,000
Common stock, par value (dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	82,294,000	61,718,000
Common stock, shares outstanding	82,104,000	61,400,000
Common stock, unvested shares	190,000	318,000
Treasury stock, shares	2,000	2,000
Series A Convertible Preferred Stock
Convertible preferred stock, par value (dollars per share)	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	15,000	15,000
Convertible preferred stock, shares issued	0	0
Convertible preferred stock, shares outstanding	0	0
Series B Convertible Preferred Stock
Convertible preferred stock, par value (dollars per share)	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	45,000	45,000
Convertible preferred stock, shares issued	0	0
Convertible preferred stock, shares outstanding	0	0

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenues:
Revenues	$ 144,861	$ 113,427
Cost of revenues	42,360	35,833
Gross profit	102,501	77,594
Operating expenses:
Research and development	18,745	13,849
Sales, general and administrative	129,156	101,714
Litigation-related	8,552	8,549
Amortization of acquired intangible assets	688	698
Transaction-related	4,223
Restructuring		60
Total operating expenses	161,364	124,870
Operating loss	(58,863)	(47,276)
Interest and other expense, net:
Interest expense, net	(12,374)	(9,865)
Loss on debt extinguishment	(7,612)
Total interest and other expense, net	(19,986)	(9,865)
Loss from continuing operations before taxes	(78,849)	(57,141)
Income tax provision (benefit)	145	(239)
Loss from continuing operations	(78,994)	(56,902)
Loss from discontinued operations, net of applicable taxes		(100)
Net loss	$ (78,994)	$ (57,002)
Loss per share, basic and diluted:
Continuing operations	$ (1.18)	$ (1.09)
Discontinued operations	0	0
Net loss per share, basic and diluted	$ (1.18)	$ (1.09)
Shares used in calculating basic and diluted net loss per share	67,020	52,234
United States Product
Revenues:
Revenues	$ 141,079	$ 108,242
International Supply Agreement
Revenues:
Revenues	$ 3,782	$ 5,185

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (78,994)	$ (57,002)
Foreign currency translation adjustments related to continuing operations	116	24
Comprehensive loss	$ (78,878)	$ (56,978)

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	SafeOp Surgical, Inc.Milestone 1 and Milestone 2	Series A Convertible Preferred Stock	Additional paid-in capital	Additional paid-in capitalSafeOp Surgical, Inc.Milestone 1 and Milestone 2	Shareholder note receivable	Treasury stock	Accumulated other comprehensive income	Accumulated deficit	Accumulated deficitCumulative Effect, Period of Adoption, Adjustment	Common Stock	Common StockSafeOp Surgical, Inc.	Common StockSafeOp Surgical, Inc.Milestone 1 and Milestone 2
Balance at Dec. 31, 2018	$ 17,574				$ 523,525		$ (5,000)	$ (97)	$ 1,064	$ (501,922)		$ 4
Balance, shares at Dec. 31, 2018				4,000								43,368,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	10,294				10,294
Common stock issued for conversion of Series A preferred stock, shares				(4,000)								1,954,000
Recognition of beneficial conversion feature - SafeOp Convertible Notes	242				242
Distributor equity incentives	322				322
Distributor equity incentives, shares												75,000
Common stock issued for warrant exercises	1,668				1,668
Common stock issued for warrant exercises, shares												757,000
Common stock issued for employee stock purchase plan and stock option exercises	1,522				1,522
Common stock issued for employee stock purchase plan and stock option exercises, shares												477,000
Common stock issued for vesting of performance and restricted stock units and restricted stock awards, net of tax liability	(1,414)				(1,414)
Common stock issued for vesting of performance and restricted stock units and restricted stock awards, net of tax liability, shares												1,347,000
Issuance of common stock warrants, net	13,664				13,664
Issuance of common stock for public offering, net of offering costs	53,848				53,846							$ 2
Issuance of common stock for public offering, net of offering costs, shares												12,535,000
Issuance of common stock for acquisition			$ 2,889			$ 2,889
Issuance of common stock for acquisition, shares													886,843	887,000
Foreign currency translation adjustments	24								24
Net loss	(57,002)									(57,002)
Balance at Dec. 31, 2019	$ 43,631	$ (81)			606,558		(5,000)	(97)	1,088	(558,924)	$ (81)	$ 6
Balance, shares at Dec. 31, 2019												61,400,000
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201908Member
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 15,730				15,730
Common stock issued for conversion of Series A preferred stock, shares												39,000
Distributor equity incentives	521				521
Common stock issued for warrant exercises	2,368				2,368
Common stock issued for warrant exercises, shares												1,907,000
Common stock issued for employee stock purchase plan and stock option exercises	1,970				1,970
Common stock issued for employee stock purchase plan and stock option exercises, shares												665,000
Common stock issued for vesting of performance and restricted stock units and restricted stock awards, net of tax liability	(983)				(983)
Common stock issued for vesting of performance and restricted stock units and restricted stock awards, net of tax liability, shares												2,238,000
Issuance of common stock warrants, net	2,974				2,974
Issuance of common stock for public offering, net of offering costs	107,698				107,696							$ 2
Issuance of common stock for public offering, net of offering costs, shares												13,143,000
Shareholder note receivable	1,000						1,000
Issuance of common stock for other services	123				123
Issuance of common stock for other services, shares												12,000
Issuance of common stock for prepayment of debt	33,807				33,807
Issuance of common stock for prepayment of debt, shares												2,700,000
Foreign currency translation adjustments	116								116
Net loss	(78,994)									(78,994)
Balance at Dec. 31, 2020	$ 129,880				$ 770,764		$ (4,000)	$ (97)	$ 1,204	$ (637,999)		$ 8
Balance, shares at Dec. 31, 2020												82,104,000

CONSOLIDATED STATEMENTS OF ST_2

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Statement Of Stockholders Equity [Abstract]
Common stock public offering cost	$ 7.3	$ 3.8

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net loss	$ (78,994)	$ (57,002)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	10,949	7,578
Stock-based compensation	17,659	10,956
Amortization of debt discount and debt issuance costs	3,974	3,709
Amortization of right-of-use assets	683	930
Provision for doubtful accounts	107	242
Provision for excess and obsolete inventory	7,044	8,624
Deferred income tax benefit	9	(438)
Beneficial conversion feature from convertible notes		242
Loss on disposal of instruments	498	127
Loss on debt extinguishment	7,612
Accretion to contingent consideration		289
Changes in operating assets and liabilities:
Accounts receivable, net	(7,484)	(1,298)
Inventories, net	(18,192)	(14,712)
Prepaid expenses and other current assets	(2,930)	186
Other assets	(51)	262
Other long-term assets		(3,308)
Accounts payable	7,130	6,003
Accrued expenses and other	8,812	6,647
Lease liability	(1,312)	2,239
Other long-term liabilities	(1,926)	(4,397)
Net cash used in operating activities	(46,412)	(33,121)
Investing activities:
Purchases of property and equipment	(23,131)	(13,032)
Cash paid for acquisition of intangible assets	(755)
Cash received from sale of equipment	27
Net cash used in investing activities	(23,859)	(13,032)
Financing activities:
Proceeds from public offering, net	107,698	53,848
Proceeds from sale of common stock, net	3,341	1,977
Borrowings under lines of credit	42,455	114,710
Repayments under lines of credit	(56,615)	(112,934)
Principal payments on capital lease obligations	(32)	(27)
Proceeds from issuance of term debt, net	34,008	9,700
Principal payments on term loan and notes payable	(26)	(3,091)
Net cash provided by financing activities	130,829	64,183
Effect of exchange rate changes on cash	94	29
Net increase in cash	60,652	18,059
Cash at beginning of year	47,113	29,054
Cash at end of year	107,765	47,113
Supplemental disclosure of cash flow information:
Cash paid for interest	6,330	5,969
Cash paid for income taxes	190	161
Supplemental disclosure of noncash investing and financing activities:
Common stock issued for partial extinguishment of debt	33,807
Common stock issued for development of intangible assets	123
Common stock warrants issued with term loan draw	2,974	13,664
Purchases of property and equipment in accounts payable	$ 3,527	1,275
SafeOp Surgical, Inc.
Supplemental disclosure of noncash investing and financing activities:
Common stock issued for achievement of SafeOp contingent consideration		$ 2,889

The Company and Basis of Presen

The Company and Basis of Presentation	12 Months Ended
	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
The Company and Basis of Presentation	1. The Company and Basis of Presentation The Company Alphatec Holdings, Inc. (the “Company”), through its wholly owned subsidiaries, Alphatec Spine, Inc. (“Alphatec Spine”) and SafeOp Surgical, Inc. (“SafeOp”), is a medical technology company that designs, develops, and markets technology for the treatment of spinal disorders associated with disease and degeneration, congenital deformities, and trauma. The Company markets its products in the U.S. via independent sales agents and a direct sales force. On March 8, 2018, the Company completed its acquisition of SafeOp, pursuant to a reverse triangular merger of SafeOp into a newly created wholly owned subsidiary of the Company, with SafeOp being the surviving corporation and a wholly-owned subsidiary of the Company. On September 1, 2016, the Company completed the sale of its international distribution operations and agreements (collectively, the “International Business”) to Globus Medical Ireland, Ltd., a subsidiary of Globus Medical, Inc., and its affiliated entities (collectively “Globus”). As a result of this transaction, the International Business has been excluded from continuing operations for all periods presented in the consolidated financial statements and is reported as discontinued operations. See Note 4 for additional information on the divestiture of the International Business. Basis of Presentation The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") and include the accounts of the Company, Alphatec Spine and SafeOp. All intercompany balances and transactions have been eliminated in consolidation. The Company operates in one reportable business segment. Recent Developments Proposed Acquisition of EOS On December 16, 2020, the Company, entered into a Tender Offer Agreement (the “Tender Offer Agreement”) with EOS imaging S.A., a société anonyme organized and existing under the laws of France (“EOS”), pursuant to which the Company will commence a public tender offer (the “Offer”) to purchase all of the issued and outstanding ordinary shares, nominal value €0.01 per share (collectively, the “EOS Shares”), and outstanding convertible bonds (“OCEANEs”), of EOS. The Offer will consist of a cash tender offer price of €2.45 (or approximately $2.99) per EOS Share and €7.01 (or approximately $8.55) per OCEANE, (the “Offer Consideration”), for a total purchase price of up to approximately $116.9 million. The Offer will need to be filed with and cleared by the Autorité des marches financiers (the “AMF”). Certain shareholders of EOS, which currently control approximately 23% of the outstanding EOS Shares, collectively, have entered into Tender Commitments with the Company pursuant to which they have agreed, among other things, to tender their respective EOS Shares into the Offer, subject to certain conditions. These Tender Commitments will terminate if (i) the Tender Offer Agreement is terminated, (ii) the Offer is withdrawn by the Company pursuant to applicable French laws and regulations, or (iii) the Offer is not declared successful by the AMF as a result of certain conditions failing to be met or waived. In connection with the Offer, on December 16, 2020, the Company entered into a securities purchase agreement (the “Purchase Agreement”) with certain institutional and accredited investors, including Squadron Capital LLC (“Squadron Capital” and collectively, the “Purchasers”), providing for the sale by the Company of 12,421,242 shares of ATEC common stock (the “Private Placement Shares”) at a purchase price of $11.11 per share (the “Private Placement Purchase Price”), in a private placement (the “Private Placement”) for aggregate gross proceeds of $138.0 million. The Company intends to use the net proceeds from the Private Placement to fund the Offer Consideration and for general corporate and working capital purposes. Pursuant to the terms of the Purchase Agreement, from the Private Placement Closing until the Offer Closing, the Company is prohibited from issuing, or entering into any agreement to issue, or announcing the issuance or proposed issuance of, any shares of ATEC c ommon s tock or ATEC c ommon s tock equivalents, subject to certain permitted exceptions. If the Tender Offer Agreement is terminated or the Offer Closing has not occurred by July 31, 2021, then the Company will repurchase the Private Placement Shares from the Purchasers for an amount per share equal to the Private Placement Purchase Price plus interest on the Private Placement Purchase Price at a rate of nine percent per year computed from the date of the Private Placement Closing to the date of the repurchase. The Company determined that since it is within control of the Company to cancel the P rivate placement before closing and the shares have not yet been issued, an obligation to issue shares d id not exist as of December 31, 2020.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, and the reported amounts of revenues and expenses. Actual results could differ from those estimates. Significant items subject to such estimates and assumptions include the useful lives of property and equipment, intangibles, allowances for doubtful accounts, the valuation of share-based liabilities, deferred tax assets, inventory, stock-based compensation, revenues, restructuring liabilities, income tax uncertainties, and other contingencies. Concentrations of Credit Risk and Significant Customers Financial instruments, which potentially subject the Company to concentrations of credit risk, consist primarily of cash and accounts receivable. The Company limits its exposure to credit loss by depositing its cash with established financial institutions. As of December 31, 2020, a substantial portion of the Company’s available cash funds is held in business accounts. Although the Company deposits its cash with multiple financial institutions, its deposits, at times, may exceed federally insured limits. The Company’s customers are primarily hospitals, surgical centers and distributors. No one single customer represented greater than 10 percent of consolidated revenues and accounts receivable for any of the years presented. Credit to customers is granted based on an analysis of the customers’ credit worthiness. Credit losses have not been significant. Accounts Receivable, net Accounts receivable are presented net of allowance for doubtful accounts. The Company makes judgments as to its ability to collect outstanding receivables and provides allowances for a portion of receivables when collection becomes doubtful. Provisions are made based upon a specific review of all significant outstanding invoices and the overall quality and age of those invoices not specifically reviewed. In determining the provision for invoices not specifically reviewed, the Company analyzes historical collection experience. If the historical data used to calculate the allowance provided for doubtful accounts does not reflect the Company’s future ability to collect outstanding receivables or if the financial condition of customers were to deteriorate, resulting in impairment of their ability to make payments, an increase in the provision for doubtful accounts may be required. The Company’s accounts year Inventories, net Inventories are stated at the lower of cost or net realizable value, with cost primarily determined under the first-in, first-out method. The Company reviews the components of inventory on a periodic basis for excess, obsolete and impaired inventory, and records a reserve for the identified items. The Company calculates an inventory reserve for estimated excess and obsolete inventory based upon historical turnover and assumptions about future demand for its products and market conditions. The Company’s biologics inventories have an expiration based on a shelf life and are subject to demand fluctuations based on the availability and demand for alternative implant products. The Company’s estimates and assumptions for excess and obsolete inventory are reviewed and updated on a quarterly basis. Increases in the reserve for excess and obsolete inventory result in a corresponding increase to cost of revenues and establish a new cost basis for the part. Property and Equipment, net Property and equipment are stated at cost, net of accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the related assets, generally ranging from three to seven years. Leasehold improvements and assets acquired under capital leases are amortized over the shorter of their useful lives or the remaining terms of the related leases. Operating Lease Effective January 1, 2019, the Company adopted ASC No. 2016‑02, Leases (Topic 842) (“ASC 842”) On December 4, 2019, the Company entered into a new lease agreement, (“New Building Lease”), for a new headquarters location in Carlsbad, California. The term of the New Building Lease commenced on February 1, 2021 and at time of lease commencement the Company applied this guidance to create an additional ROU asset and operating lease liability on the Company’s consolidated balance sheet. Rent expense for operating leases is recognized on a straight-line basis over the reasonably assured lease term based on the total lease payments and is included in research and development and general and administrative expenses in the consolidated statements of operations. Goodwill and Intangible Assets The Company’s goodwill represents the excess of the cost over the fair value of net assets acquired from its business combination with SafeOp. The determination of the value of goodwill and intangible assets arising from its business combination and asset acquisitions requires extensive use of accounting estimates and judgments to allocate the purchase price to the fair value of the net tangible and intangible assets acquired, including capitalized Intangible assets acquired in a business combination that are used for IPR&D are considered indefinite lived until the completion or abandonment of the associated research and development efforts. Upon reaching the end of the relevant research and development project, the Company will amortize the acquired IPR&D over its estimated useful life or expense the acquired IPR&D should the research and development project be unsuccessful with no future alternative use. Goodwill and IPR&D are not amortized; however, they are assessed for impairment using fair value measurement techniques on an annual basis or more frequently if facts and circumstance warrant such a review. The goodwill or IPR&D are considered to be impaired if the Company determines that the carrying value of the reporting unit or IPR&D exceeds its respective fair value. The Company performs its annual impairment analysis by comparing the Company’s estimated fair value, calculated from t he Company’s market capitalization, The Company completed its most recent annual evaluation for impairment as of December 31, 2020 and determined that no impairment existed and, consequently, no impairment charge has been recorded during the year Intangible assets with a finite life, such as acquired technology, customer relationships, manufacturing know-how, licensed technology, supply agreements and certain trade names and trademarks, are amortized on a straight-line basis over their estimated useful life, ranging from one to twenty-year The Company evaluates its intangible assets with finite lives for indications of impairment whenever events or changes in circumstances indicate that the carrying value may not be recoverable. Factors that could trigger an impairment review include significant under-performance relative to expected historical or projected future operating results, significant changes in the manner of the Company’s use of the acquired assets or the strategy for the Company’s overall business or significant negative industry or economic trends. If this evaluation indicates that the value of the intangible asset may be impaired, the Company makes an assessment of the recoverability of the net carrying value of the asset over its remaining useful life. If this assessment indicates that the intangible asset is not recoverable, based on the estimated undiscounted future cash flows of the technology over the remaining amortization period, the Company reduces the net carrying value of the related intangible asset to fair value and may adjust the remaining amortization period. There were no impairment charges during the years ended December 31, 2020 or 2019. Impairment of Long-Lived Assets The Company assesses potential impairment to its long-lived assets when there is evidence that events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. An impairment loss is recognized when the carrying amount of the long-lived assets is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. Any required impairment loss is measured as the amount by which the carrying amount of a long-lived asset exceeds its fair value and is recorded as a reduction in the carrying value of the related asset and a charge to operating results. There were no impairment charges during the years ended December 31, 2020 or 2019. Warrants to Purchase Common Stock Warrants are accounted for in accordance with the applicable accounting guidance as either derivative liabilities or as equity instruments depending on the specific terms of the agreements. Liability-classified instruments are recorded at fair value at each reporting period with any change in fair value recognized as a component of change in fair value of derivative liabilities in the consolidated statements of operations. All warrants issued in 2020 and 2019 qualified for classification within stockholders’ equity and, therefore, did not require liability accounting. Fair Value Measurements The carrying amount of financial instruments consisting of cash, trade accounts receivable, prepaid expenses and other current assets, accounts payable, accrued expenses, accrued compensation and current portion of long-term debt included in the Company’s consolidated financial statements are reasonable estimates of fair value due to their short maturities. Based on the borrowing rates currently available to the Company for loans with similar terms, management believes the fair value of long-term debt approximates its carrying value. Authoritative guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Level 2: Level 3: T he Company does not maintain any financial assets that are considered to be Level 1, Level 2 or Level 3 instruments as of the years ended December 31, 2020 or December 31,2019. Liabilities measured Balance at Year Ended December 31, 2020 Level 1 Level 2 Level 3 Liability classified equity award* $ 4,108 — — $ 4,108 Foreign currency forward contract $ 878 — $ 878 — Balance at Year Ended December 31, 2019 Level 1 Level 2 Level 3 Liability classified equity award* $ 1,705 — — $ 1,705 *a portion of this liability is being accreted over the requisite service period On December 18, 2020, the Company entered into a foreign currency forward contract, with a notional amount of $117.9 million to mitigate the foreign currency exchange risk related to the Company’s Tender Offer Agreement, denominated in Euros ("EUR"). The contract is not designated as a hedging instrument. The Company has classified the derivative liability within Level 2 of the fair value hierarchy as observable inputs are available for the full term of the derivative instrument. The fair value of the forward contract was developed using a market approach based on publicly available market yield curves and the term of the contract. For the year ended December 31, 2020, the Company recognized a $0.9 million loss from the change in fair value of the contract, which was included in other expense, net in the consolidated statement of operations. A corresponding liability of $0.9 million related to the forward contract was included in accrued expenses on the Company’s consolidated balance sheet as of December 31, 2020. In 2019, the fair value of the contingent consideration liability assumed in the SafeOp acquisition was recorded as part of the purchase price consideration of the acquisition. The contingent consideration related to the SafeOp acquisition was classified within Level 3 of the fair value hierarchy as the Company was using a probability-weighted income approach, utilizing significant unobservable inputs including the probability of achieving each of the potential milestones and an estimated discount rate related to the risks of the expected cash flows attributable to the milestones. All the contingent milestones were achieved as of December 31, 2019. During the year ended December 31, 2019, the Company achieved the second of the two milestones related to the acquisition of SafeOp, which was settled through the issuance of 886,843 shares of the Company’s common stock. During the second quarter of 2019, the Company issued a liability classified equity award to one of its executive officers. The award will be earned over a 4-year vesting period and upon a specific market condition. As the award will be cash settled, it is classified as a liability within Level 3 of the fair value hierarchy as the Company is using a probability-weighted income approach, utilizing significant unobservable inputs including the probability of achieving the specified market condition with the valuation updated at each reporting period. The full fair value of the cash settled award was $ 4.1 million and $ 1.7 million as of December 31, 2020 and December 31, 2019, respectively. The fair value of the award is being recognized ratably as the underlying service period is provided . The following table provides a reconciliation of liabilities measured at fair value on a recurring basis as of December and Level 3 Liabilities Balance at December 31, 2018 $ 2,600 Settlement of milestone #2 (2,889 ) Change in fair value measurement- milestone #2 289 Straight line recognition of liability classified equity award 173 Change in fair value measurement of liability classified equity award 93 Balance at December 31, 2019 266 Straight line recognition of liability classified equity award 371 Change in fair value measurement of liability classified equity award 1,031 Balance at December 31, 2020 $ 1,668 Revenue Recognition The Company recognizes revenue from product sales in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers The Company derives its revenues primarily from the sale of spinal surgery implants and products used in the treatment of spine disorders. The Company sells its products primarily through its direct sales force and independent distributors. Revenue is recognized when control of the promised goods is transferred to the customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods. Transfer of control generally occurs when the Company receives the written acknowledgment that the product has been used in a surgical procedure or upon shipment to third-party customers who immediately accept title to such product. Research and Development Expenses Research and development expenses consist of costs associated with the design, development, testing, and enhancement of the Company’s products and technologies. Research and development costs also include salaries and related employee benefits, research-related overhead expenses, and fees paid to external service providers. Research and development costs are expensed as incurred. Litigation-related Expenses Litigation-related expenses are costs incurred for the ongoing litigation, primarily with NuVasive, Inc . See Note 6 for further information. Transaction-related Expenses The Company expensed certain costs incurred throughout the year related to the prior tender offer agreement entered into with EOS on February 28, 2020, which was subsequently terminated by the Company in response to the then-expected market effects of the COVID-19 pandemic on April 24, 2020, as well as costs incurred related to the renewed tender offer agreement entered into with EOS on December 16, 2020. These expenses primarily include third-party advisory and legal fees . Product Shipment Cost Product shipment costs are included in sales and marketing expenses in the accompanying consolidated statements of operations. Product shipment costs totaled $5.3 million and $4.0 million for the years ended December 31, 2020 and 2019, respectively. Stock-Based Compensation The Company accounts for stock-based compensation under provisions which require that share-based payment transactions with employees be recognized in the financial statements based on their fair value and recognized as compensation expense over the vesting period. The amount of expense recognized during the period is affected by subjective assumptions, including estimates of the future volatility of the Company’s stock price, the expected term for its stock options, the number of options expected to ultimately vest, and the timing of vesting for the Company’s share-based awards. The Company uses a Black-Scholes option pricing valuation model to estimate the fair value of its stock option awards. The calculation of the fair value of the awards using the Black-Scholes option pricing model is affected by the Company’s common stock price on the date of grant as well as assumptions regarding the following: • Estimated volatility is a measure of the amount by which the Company’s common stock price is expected to fluctuate each year during the expected life of the award. The Company’s estimated volatility through December 31, 2020 was based on a weighted-average volatility of its actual historical volatility over a period equal to the expected life of the awards. • The expected term represents the period of time that awards granted are expected to be outstanding. Through December 31, 2020, the Company calculated the expected term using a weighted-average term based on historical exercise patterns and the term from option date to full exercise for the options granted within the specified date range. • The risk-free interest rate is based on the yield curve of a zero-coupon U.S. Treasury bond on the date the stock option award is granted with a maturity equal to the expected term of the stock option award. • The assumed dividend yield is based on the Company’s expectation of not paying dividends in the foreseeable future. The Company uses historical data to estimate the number of future stock option forfeitures. Stock-based compensation recorded in the Company’s consolidated statements of operations is based on awards expected to ultimately vest and has been reduced for estimated forfeitures. The Company’s estimated forfeiture rates may differ from its actual forfeitures which would affect the amount of expense recognized during the period. The Company accounts for stock option grants to non-employees in accordance with provisions which require that the fair value of these instruments be recognized as an expense over the period in which the related services are rendered. Stock-based compensation expense of awards with performance conditions is recognized over the period from the date the performance condition is determined to be probable of occurring through the time the applicable condition is met. Determining the likelihood and timing of achieving performance conditions is a subjective judgment made by management which may affect the amount and timing of expense related to these share-based awards. Share-based compensation is adjusted to reflect the value of options which ultimately vest as such amounts become known in future periods. Stock-based awards with market conditions are valued using the Monte Carlo valuation technique which requires management to make significant estimates and assumptions that are not observable from the market. Stock based compensation for awards with both service and market conditions that contain one vesting date are recognized on a straight-line basis over the longer of the derived service period or the requisite service period. For awards with both service and market conditions with various vesting dates, stock-based compensation is recognized utilizing an accelerated expense model over the longer of the derived service period or the requisite service period. Valuation of Stock Option Awards The weighted average assumptions used to compute the stock-based compensation costs for the stock options granted during the years ended December 31, 2020 and 2019 are as follows: Year Ended December 31, 2020 2019 Risk-free interest rate 1.03 % 2.00 % Expected dividend yield — — Weighted average expected life (years) 6.08 6.09 Volatility 84.00 % 80.76 % Stock-Based Compensation Costs The compensation cost that has been included in the Company’s consolidated statements of operations for all stock-based compensation arrangements is detailed as follows (in thousands): Year Ended December 31, 2020 2019 Cost of revenues $ 512 $ 146 Research and development 2,114 752 Sales, general and administrative 15,033 10,058 Total $ 17,659 $ 10,956 Income Taxes The Company accounts for income taxes in accordance with provisions which set forth an asset and liability approach that requires the recognition of deferred tax assets and deferred tax liabilities for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of assets and liabilities. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. In making such determination, a review of all available positive and negative evidence must be considered, including scheduled reversal of deferred tax liabilities, projected future taxable income, tax planning strategies, and recent financial performance. The Company recognizes interest and penalties related to uncertain tax positions as a component of the income tax provision. Net Loss per Share Basic earnings per share (“EPS”) is calculated by dividing the net income or loss available to common stockholders by the weighted average number of shares of common stock outstanding for the period without consideration for common stock equivalents. Diluted EPS is computed by dividing the net income or loss available to common stockholders by the weighted average number of shares of common stock outstanding for the period and the weighted average number of dilutive common stock equivalents outstanding for the period determined using the treasury-stock method. For purposes of this calculation, common stock subject to repurchase by the Company, common stock issuable upon conversion of preferred shares, options and warrants are considered to be common stock equivalents and are only included in the calculation of diluted earnings per share when their effect is dilutive. The following table sets forth the computation of basic and diluted loss per share (in thousands, except per share data): Year Ended December 31, 2020 2019 Numerator: Net loss, basic and diluted $ (78,994 ) $ (57,002 ) Denominator: Weighted average common shares outstanding 67,200 52,520 Weighted average unvested common shares subject to repurchase (180 ) (286 ) Weighted average common shares outstanding - basic and diluted 67,020 52,234 Net loss per share, basic and diluted $ (1.18 ) $ (1.09 ) The anti-dilutive securities not included in diluted net loss per share were as follows calculated on a weighted average basis (in thousands): Year Ended December 31, 2020 2019 Options to purchase common stock 3,951 4,215 Warrants to purchase common stock 24,881 26,557 Series A convertible preferred stock 29 67 Unvested restricted stock awards 8,216 6,727 37,077 37,566 Recent Accounting Pronouncements Recently Adopted Accounting Pronouncements In December 2019, the Financial Accounting Standards Board (the “FASB”) issued ASU 2019-12, Income Taxes (Topic 740) intended to simplify the accounting for income taxes. The guidance removes the following exceptions: (1) exception to the incremental approach for intraperiod tax allocation when there is a loss from continuing operations and income or a gain from other items, (2) exception to the requirement to recognize a deferred tax liability for equity method investments when a foreign subsidiary becomes an equity method investment, (3) exception to the ability not to recognize a deferred tax liability for a foreign subsidiary when a foreign equity method investment becomes a subsidiary, and (4) exception to the general methodology for calculating income taxes in an interim period when a year-to-date loss exceeds the anticipated loss for the year. Additionally, the guidance simplifies the accounting for income taxes by: (1) requiring that an entity recognize a franchise tax (or similar tax) that is partially based on income as an income-based tax and account for any incremental amount incurred as a non-income-based tax, (2) requiring that an entity evaluate when a step up in the tax basis of goodwill should be considered part of the business combination in which the book goodwill was originally recognized and when it should be considered a separate transaction, (3) specifying that an entity is not required to allocate the consolidated amount of current and deferred tax expense to a legal entity that is not subject to tax in its separate financial statements (although the entity may elect to do so (on an entity-by-entity basis) for a legal entity that is both not subject to tax and disregarded by the taxing authority), (4) requiring that an entity reflect the effect of an enacted change in tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date, and (5) making minor improvements for income tax accounting related to employee stock ownership plans and investments in qualified affordable housing projects accounted for using the equity method. The guidance will be effective for fiscal years and interim periods beginning after December 15, 2020. Different components of the guidance require retrospective, modified retrospective or prospective adoption, and early adoption is permitted . The Company early adopted this standard on January 1, 2020 , and the adoption of the standard did not have a material impact to our consolidated financial statements. In November 2019, the FASB issued Accounting Standards Update (“ASU”) 2019-08, Compensation—Stock Compensation In August 2018, the FASB issued ASU 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40), which aligns the accounting for cloud computing implementation costs with that of costs to develop or obtain internal-use software, meaning such costs that are part of the application development stage are capitalized as an asset and amortized over the term of the arrangement, otherwise, such costs are expensed as incurred. It also clarifies the classification of amounts related to capitalized implementation costs in the financial statements. ASU 2018-15 is effective for annual reporting periods beginning after December 15, 2019, including interim reporting periods within those annual reporting periods. Early adoption is permitted. The Company adopted the guidance effective January 1, 2020. It did not have a material impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other Recently Issued Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40)

Balance Sheet Details

Balance Sheet Details	12 Months Ended
	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Details	3. Balance Sheet Details Accounts Receivable, net Accounts receivable consist of the following (in thousands): December 31, 2020 2019 Accounts receivable $ 23,887 $ 16,436 Less allowance for doubtful accounts (360 ) (286 ) Accounts receivable, net $ 23,527 $ 16,150 Inventories, net Inventories consist of the following (in thousands): December 31, 2020 2019 Raw materials $ 6,064 $ 5,822 Work-in-process 1,982 1,578 Finished goods 67,892 51,669 75,938 59,069 Less reserve for excess and obsolete (29,937 ) (24,215 ) Inventories, net $ 46,001 $ 34,854 Property and Equipment, net Property and equipment consist of the following (in thousands, except as indicated): Useful lives December 31, (in years) 2020 2019 Surgical instruments 4 $ 76,669 $ 58,502 Machinery and equipment 7 6,562 6,038 Computer equipment 3 4,206 3,594 Office furniture and equipment 5 1,380 1,297 Leasehold improvements various 1,761 1,761 Construction in progress n/a 2,738 496 93,316 71,688 Less accumulated depreciation and amortization (56,646 ) (51,966 ) Property and equipment, net $ 36,670 $ 19,722 Total depreciation expense was $9.2 million and $6.8 million for the years ended December 31, 2020 and 2019, respectively. At December 31, 2020 and 2019, assets recorded under capital leases of $0.1 million were included in the machinery and equipment balance. Amortization of assets under capital leases is included in depreciation expense. Intangible Assets, net Intangible assets, net consist of the following (in thousands, except as indicated): Remaining Avg. Useful lives Gross Accumulated Intangible December 31, 2020: (in years) Amount Amortization Assets, net Developed product technology 12 $ 35,376 $ (23,056 ) $ 12,320 License agreements 1 5,536 (965 ) 4,571 Trademarks and trade names — 792 (119 ) 673 Customer-related 3 7,458 (3,968 ) 3,490 Distribution network 2 4,027 (1,639 ) 2,388 In process research and development 7 1,278 — 1,278 Total $ 54,467 $ (29,747 ) $ 24,720 Remaining Avg. Useful lives Gross Accumulated Intangible December 31, 2019: (in years) Amount Amortization Assets, net Developed product technology 12 $ 35,376 $ (22,206 ) $ 13,170 Intellectual Property — 1,004 (1,004 ) — License agreements 1 5,536 (740 ) 4,796 Trademarks and trade names — 792 (119 ) 673 Customer-related 4 7,458 (3,481 ) 3,977 Distribution network 3 4,027 (1,438 ) 2,589 In process research and development 7 400 — 400 Total $ 54,593 $ (28,988 ) $ 25,605 Total expense related to amortization of intangible assets was $1.8 million and $0.7 million for the years ended December 31, 2020 and 2019, respectively. Future amortization expense related to intangible assets as of December 31, 2020 is as follows (in thousands): Year Ending December 31, 2021 $ 2,014 2022 2,014 2023 2,014 2024 1,911 2025 1,326 Thereafter 15,441 Total $ 24,720 Accrued Expenses Accrued expenses consist of the following (in thousands): December 31, 2020 2019 Commissions and sales milestones $ 6,734 $ 5,299 Payroll and payroll related 12,247 7,949 Litigation settlement obligation - short-term portion 4,000 4,400 Professional fees 3,551 3,945 Royalties 2,293 1,981 Interest 619 155 Other 5,787 2,687 Total accrued expenses $ 35,231 $ 26,416 Other Long-Term Liabilities Other long-term liabilities consist of the following (in thousands): December 31, 2020 2019 Litigation settlement obligation - long-term portion $ 7,634 $ 10,712 Line of credit exit fee — 600 Tax liabilities 373 373 Royalties 1,678 — Other 1,668 266 Other long-term liabilities $ 11,353 $ 11,951

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2020
Discontinued Operations And Disposal Groups [Abstract]
Discontinued Operations	4. Discontinued Operations In connection with the sale of the International Business, the Company entered into a product manufacture and supply agreement (the “Supply Agreement”) with Globus, pursuant to which the Company supplies to Globus certain of its implants and instruments, previously offered for sale by the Company in international markets at agreed-upon prices for a minimum term of three years, with the option for Globus to extend the term for up to two additional twelve month periods subject to Globus meeting specified purchase requirements. During the second quarter of 2020, Globus notified the Company that it will exercise the option to extend the agreement for the second additional twelve-month

Debt

Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	5. Debt MidCap Facility Agreement On May 29, 2020, the Company repaid in full all amounts outstanding under the Amended Credit Facility with MidCap Funding IV, LLC (“MidCap”). The Company made a final payment of $9.6 million to MidCap, consisting of outstanding principal and accrued interest. All amounts previously recorded as debt issuance costs were recorded as part of loss on debt extinguishment on the Company’s consolidated statement of operations for the year ended December 31, 2020. Squadron Medical Credit Agreement On November 6, 2018, the Company entered into a Term Loan with Squadron Medical Finance Solutions, LLC (“Squadron Medical”), a provider of debt financing to growing companies in the orthopedic industry. The Term Loan was subsequently amended March 2019, May 29, 2020 and December 16, 2020 to expand the availability of additional term loans, extend the maturity, remove all financial covenant requirements and, in the December 2020 amendment, to incorporate a debt exchange. On December 16, 2020, the Company amended the Term Loan to expand the credit facility by an additional $15.0 million and to extend the maturity of the Term Loan to June 30, 2026. In conjunction with the Term Loan amendment on December 16, 2020, the Company entered into a debt exchange agreement whereby the Company exchanged $30.0 million of the Company’s outstanding debt obligations pursuant to the Term Loan dated as of November 6, 2018, as amended, for the issuance of 2,700,270 shares of the Company’s Common Stock to Squadron Capital LLC and a participant lender, based on a price of $11.11 per share. The debt exchange resulted in additional debt issuance costs of $3.8 million calculated as the difference between the Company’s stock price on the date of issuance and the issuance price. The total principal outstanding under the Term Loan as of December 31, 2020 was $45.0 million, with an additional $40.0 million in available borrowings. The Term Loan bears interest at LIBOR plus 8.0% per annum, subject to a 9.0% floor and 12.0% ceiling. Interest-only payments are due monthly until December 2023 and joined by $1.0 million monthly principal payments beginning December 2023. Any remaining principal amounts of the Term Loan will be due on June 30, 2026. In addition to paying interest on outstanding principal on the Term Loan, the Company will pay a commitment fee at a rate of 1.0% per annum to Squadron Medical in respect of the unutilized Term Loan. As collateral for the Term Loan, Squadron Medical has a first lien security interest in substantially all assets . In connection with the initial 2018 financing, the Company issued initial warrants to Squadron Medical and a participant lender to purchase 845,000 shares of common stock at an exercise price of $3.15 per share. In conjunction with the first draw under the first amendment of the Term Loan in 2019, the Company issued to Squadron Medical and the participant lender warrants to purchase an additional 4,838,710 shares of the Company’s common stock at an exercise price of $2.17 per share. utilizing the Monte-Carlo simulation model as described further in Note 10 and are recorded within equity in accordance with authoritative accounting guidance and recorded as a debt discount. The Company accounted for the March 2019, May 2020, and December 2020 amendments of the Term Loan as debt modifications with continued amortization of the existing and inclusion of the new debt issuance costs amortized into interest expense utilizing the effective interest rate method. The Company determined that the $30.0 million pre-payment associated with the December 16, 2020 amendment should be accounted for as a partial extinguishment of the November 6, 2018 Term Loan, as amended. As a result of the partial extinguishment the Company elected, as an accounting policy in accordance with ASC 470-50-40-2, to write off a proportionate amount of the unamortized fees at the time that the financing was partially settled in accordance with the terms of the Term Loan dated November 6, 2018, as amended. The unamortized debt issuance costs are allocated between the remaining original loan balance and the portion of the loan paid down on a pro-rata basis. At the time of prepayment, the Company recorded a loss on extinguishment of $6.1 million and capitalized $3.8 million in non-cash debt issuance closing costs. As of December 31, 2020, the debt is recorded at its carrying value of $32.2 million, net of issuance costs of $12.8 million, including all amounts paid to third parties to secure the debt and the fair value of the warrants issued. The total debt discount will be amortized into interest expense through maturity of the debt utilizing the effective interest rate method. Paycheck Protection Loan On April 23, 2020, the Company received the proceeds from a loan in the amount of approximately $4.3 million (the “PPP Loan”) from Silicon Valley Bank, as lender, pursuant to the Paycheck Protection Program (“PPP”) of the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”). The PPP Loan matures on April 21, 2022 and bears interest at a rate of 1.0 % per annum. Commencing August 21, 2021, the Company is required to pay the lender equal monthly payments of principal and interest as required to fully amortize by April 21, 2022 the principal amount outstanding on the PPP Loan as of the date prescribed by guidance issued by U.S. Small Business Administration (“ SBA”). The PPP Loan is evidenced by a promissory note dated April 21, 2020 (the “Note”), which contains customary events of default relating to, among other things, payment defaults and breaches of representations and warranties. The PPP Loan may be prepaid by the Company at any time prior to maturity with no prepayment penalties. All or a portion of the PPP Loan may be forgiven by the SBA upon application. The Company submitted its application for forgiveness of the loan in November 2020. Under the CARES Act, loan forgiveness is available for the sum of documented payroll costs, covered rent payments, covered mortgage interest and covered utilities during the twenty-four-week period, beginning on the date of loan approval. For purposes of the CARES Act, payroll costs exclude compensation of an individual employee in excess of $100,000, prorated annually. Not more than 25% of the forgiven amount may be for non-payroll costs. Forgiveness is reduced if full-time headcount declines, or if salaries and wages for employees with salaries of $100,000 or less annually are reduced by more than 25%. In the event the PPP Loan, or any portion thereof, is forgiven pursuant to the PPP, the amount forgiven is applied to outstanding principal. The Company used all of the proceeds from the PPP Loan to retain employees and maintain payroll. Although the Company has applied for loan forgiveness as afforded by the PPP, no assurance can be provided that such loan forgiveness will be granted in whole or in part. As such, the PPP Loan is recorded as long-term debt on the Company’s consolidated balance sheet. Inventory Financing In November 2018, the Company entered into an Inventory Financing Agreement with a key inventory and instrument components supplier whereby the Company may draw up to $3.0 million for the purchase of inventory to accrue interest at a rate of LIBOR plus 8.0% subject to a 10.0% floor and 13.0% ceiling. In November 2020, the Company amended the agreement with the supplier to increase the available draw to $6.0 million. All principal will become due and payable upon maturity on November 6, 2023 and all interest will be paid monthly. The obligation outstanding under the Inventory Financing Agreement as of December 31, 2020 was $3.8 million. Other Debt Agreements The Company has one outstanding capital lease arrangement as of December 31, 2020. The lease bears interest at an annual rate of 6.4% and is due in monthly principal and interest installments, collateralized by the related equipment, and matures in December 2022. Long-term debt consists of the following (in thousands): December 31, 2020 2019 Squadron Medical Term Loan $ 45,000 $ 45,000 Amended Credit Facility with MidCap — 12,785 Inventory Financing 3,821 2,987 Note payable for software agreements, insurance premiums and PP&E 1,887 457 PPP Loan 4,271 — Total 54,979 61,229 Add: capital leases 69 101 Less: debt discount (12,814 ) (7,393 ) Total 42,234 53,937 Less: current portion of long-term debt (4,200 ) (489 ) Total long-term debt, net of current portion $ 38,034 $ 53,448 Principal payments on debt are as follows as of December 31, 2020 (in thousands): Year Ending December 31, 2021 $ 4,167 2022 1,949 2023 4,845 2024 12,018 2025 and thereafter 32,000 Total 54,979 Add: capital lease principal payments 69 Less: debt discount (12,814 ) Total 42,234 Less: current portion of long-term debt (4,200 ) Long-term debt, net of current portion $ 38,034

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies Leases The Company occupies approximately 76,000 square feet of office, engineering, and research and development space in Carlsbad, California. Monthly rent is approximately $118,000 per month for the year ended December 31, 2020 and increases by approximately $3,000 per month each year through expiration of the lease on July 31, 2021. On December 4, 2019, the Company entered into a new lease agreement for a new headquarters location which consists of 121,541 square feet of office, engineering, and research and development space in Carlsbad, California. The term of the new lease commenced on February 1, 2021 and will terminate on January 31, 2031, subject to two (2) sixty (60) month options to renew. The Company recognized a ROU asset and liability upon taking control of the premises on the lease commencement date. Base rent under the new building lease for the first twelve months of the term will be $195,000 per month subject to full abatement during months two through ten. Base rent for the second year of the term will be $244,115 per month and thereafter will increase annually by 3.0%. At the beginning of each exercised option period, base rent will be adjusted to the market rental value, and thereafter will increase annually by 3.0% through the end of such option period. Operating Lease The Company leases its buildings and certain equipment under operating leases which expire on various dates through 2021. Upon the Company’s adoption of ASC 842 on January 1, 2019, the Company recognized a ROU asset and lease liability for its building lease, assuming a 10.5% discount rate. Any short-term leases defined as 12 months or less or month-to-month leases were excluded and continue to be expensed each month. Total costs associated with these leases for the year ended December 31, 2020 was immaterial. The Company determines if an arrangement is a lease at inception. The Company has operating leases for its buildings and certain equipment with lease terms of 1 year to 10 years, some of which include options to extend and/or terminate the lease. The exercise of lease renewal options is at the Company’s sole discretion and were not included in the calculation of the Company’s lease liability as the Company is not able to determine without uncertainty if the renewal option will be exercised. The depreciable life of assets and leasehold improvements are limited to the expected term unless there is a transfer of title or purchase option reasonably certain of exercise. The Company’s lease agreements do not contain any variable lease payments, residual value guarantees or any restrictive covenants. The Company’s ROU asset represents the right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date of the lease or the ASC 842 adoption date, whichever is later, based on the present value of lease payments over the lease term. When readily determinable, the Company uses the implicit rate in determining the present value of lease payments, or 10.5% as of the adoption date. When leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the lease commencement date or adoption date, including the lease term. The operating lease ROU asset also includes any lease payments made and excludes lease incentives. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Future minimum annual undiscounted lease payments under the Company’s operating and capital leases are as follows (in thousands): Year ending December 31, 2021 $ 918 2022 40 Total undiscounted lease payments 958 Less: present value adjustment (32 ) Operating lease liability 926 Less: current portion of operating lease liability (885 ) Operating lease liability, less current portion $ 41 As of December 31, 2020, the Company’s remaining average lease term is Purchase Commitments The Company entered into a distribution agreement with a third-party provider in January 2020 in which the Company is obligated to certain minimum purchase requirements related to inventory and equipment leases. As of December 31, 2020, the minimum purchase commitment required by the Company under the agreement was $3.2 million to be paid over a three-year Litigation The Company is and may become involved in various legal proceedings arising from its business activities. While management is not aware of any litigation matter that in and of itself would have a material adverse impact on the Company’s consolidated results of operations, cash flows or financial position, litigation is inherently unpredictable, and depending on the nature and timing of a proceeding, an unfavorable resolution could materially affect the Company’s future consolidated results of operations, cash flows or financial position in a particular period. The Company assesses contingencies to determine the degree of probability and range of possible loss for potential accrual or disclosure in the Company’s consolidated financial statements. An estimated loss contingency is accrued in the Company’s consolidated financial statements if it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Because litigation is inherently unpredictable and unfavorable resolutions could occur, assessing contingencies is highly subjective and requires judgments about future events. When evaluating contingencies, the Company may be unable to provide a meaningful estimate due to a number of factors, including the procedural status of the matter in question, the presence of complex or novel legal theories, and/or the ongoing discovery and development of information important to the matters. In addition, damage amounts claimed in litigation against the Company may be unsupported, exaggerated or unrelated to reasonably possible outcomes, and as such are not meaningful indicators of the Company’s potential liability. In February 2018, NuVasive, Inc. filed suit against the Company in the United States District Court for the Southern District of California ( NuVasive, Inc. v. Alphatec Holdings, Inc. et al. , Case No. 3:18-cv-00347-CAB-MDD (S.D. Cal.)), alleging that certain of the Company’s products (including components of its Battalion™ Lateral System), infringe, or contribute to the infringement of, U.S. Patent Nos. 7,819,801, 8,355,780, 8,439,832, 8,753,270, 9,833,227 (entitled “Surgical access system and related methods”), U.S. Patent No. 8,361,156 (entitled “Systems and methods for spinal fusion”), and U.S. Design Patent Nos. D652,519 (“Dilator”) and D750,252 (“Intervertebral Implant”). NuVasive seeks unspecified monetary damages and an injunction against future purported infringement. In March 2018, the Company moved to dismiss NuVasive’s claims of infringement of its design patents for failure to state a cognizable legal claim. In May 2018, the Court ruled that NuVasive failed to state a plausible claim for infringement of the asserted design patents and dismissed those claims with prejudice. The Company filed its answer, affirmative defenses and counterclaims to NuVasive’s remaining claims in May 2018. Also in March 2018, NuVasive moved for a preliminary injunction. In March 2018, the Court denied that motion without prejudice for failure to comply with the Court’s chambers rules. In April 2018, NuVasive again moved for a preliminary injunction. In July 2018, after a hearing on the matter in June 2018, the Court denied that motion on the grounds that NuVasive failed to establish either likelihood of success on the merits or that it would suffer irreparable harm absent injunction. In September 2018, NuVasive filed an Amended Complaint, asserting additional infringement claims of U.S. Patent Nos. 9,924,859, 9,974,531 and 8,187,334. The Company filed its answer, affirmative defenses and counterclaims to these claims in October 2018. Also in October 2018, NuVasive moved to dismiss the Company’s counterclaims that intentionally had misled the U.S. Patent and Trademark Office as a means of obtaining certain patents asserted against the Company . In January 2019, the Court denied NuVasive’s motion as to all but one counterclaim, but granted the Company leave to amend that counterclaim to cure dismissal. The Company amended that counterclaim in February 2019 and, that same month, NuVasive again moved to dismiss it. In March 2019, the Court denied NuVasive’s motion. NuVasive filed its Answer to the amended counterclaim in April 2019. In December 2018, the Company filed a petition with the Patent Trial and Appeal Board (“PTAB”) challenging the validity of certain claims of the ’156 and ’334 Patents . In July 2019, PTAB instituted IPR of the validity of asserted claims of the two patents at issue. In July 2019, PTAB instituted IPR of the validity of asserted claims of the two patents at issue and held a hearing on the matter in April 2020. In July 2020, the PTAB ruled that all challenged claims of the ‘156 Patent were valid (not unpatentable) and ruled that several challenged claims of the ‘334 Patent were invalid, while finding that other challenged claims of the ‘334 Patent valid. NuVasive and the Company have both appealed the PTAB’s written decision on the matter. The appeals are currently pending before the U.S. Court of Appeals for the Federal Circuit. No briefing or hearing schedule has been set. In January 2020, NuVasive filed a Motion for Partial Summary Judgment of infringement and validity of the ’832, ’780 and ’270 Patents and the Company filed a Motion for Summary Judgment of non-infringement of all asserted claims and of invalidity of the ’832 Patent and for dismissal of NuVasive’s claim for lost profits and its allegations of assignor estoppel. In April 2020, the Court granted NuVasive’s Motion as to the alleged infringement of the ’832 Patent only and denied NuVasive’s Motion in all other respects. Also, in April 2020, the Court granted the Company’s Motion as to dismissal of the allegations of assignor estoppel and denied the Company’s Motion in all other respects. In January 2021, NuVasive filed a Motion for Partial Summary Judgment of infringement and validity of the ’156 and ’334 Implant Patents and the Company filed a Motion for Summary Judgment of invalidity of those same patents. The parties currently are briefing the respective motions. Hearing on the motions is set for March 2021. Trial is scheduled to take place in June 2021. The Company believes that the allegations lack merit and intends to vigorously defend all claims asserted. A liability is recorded in the consolidated financial statements if it is believed to be probable that a loss has been incurred and the amount of the loss can be reasonably estimated. It is impossible at this time to assess whether the outcome of this proceeding will have a material adverse effect on the Company’s consolidated results of operations, cash flows or financial position. Therefore, in accordance with authoritative accounting guidance, the Company has not recorded any accrual for a contingent liability associated with this legal proceeding based on its belief that a liability, while possible, is not probable and any range of potential future charge cannot be reasonably estimated at this time. Indemnifications In the normal course of business, the Company enters into agreements under which it occasionally indemnifies third-parties for intellectual property infringement claims or claims arising from breaches of representations or warranties. In addition, from time to time, the Company provides indemnity protection to third-parties for claims relating to past performance arising from undisclosed liabilities, product liabilities, environmental obligations, representations and warranties, and other claims. In these agreements, the scope and amount of remedy, or the period in which claims can be made, may be limited. It is not possible to determine the maximum potential amount of future payments, if any, due under these indemnities due to the conditional nature of the obligations and the unique facts and circumstances involved in each agreement. In October 2017, NuVasive filed a lawsuit in Delaware Chancery Court against Mr. Miles, the Company’s Chairman and CEO, who was a former officer and board member of NuVasive. The Company itself was not initially a named defendant in this lawsuit; however, on June 28, 2018, NuVasive amended its complaint to add the Company as a defendant. As of December 31, 2020, the Company has not recorded any liability on the consolidated balance sheet related to this matter. On October 12, 2018, the Delaware Court ordered that NuVasive begin advancing legal fees for Mr. Miles’ defense in the lawsuit, as well as Mr. Miles’ legal fees incurred in pursuing advancement of his fees, pursuant to an indemnification agreement between NuVasive and Mr. Miles. Royalties The Company has entered into various intellectual property agreements requiring the payment of royalties based on the sale of products that utilize such intellectual property. These royalties primarily relate to products sold by Alphatec Spine and are based on fixed fees or calculated either as a percentage of net sales or on a per-unit sold basis. Royalties are included on the accompanying consolidated statements of operations as a component of cost of revenues. As of December 31, 2020, the Company is obligated to pay guaranteed minimum royalty payments under these agreements of approximately $4.9 million through 2025 and beyond

Orthotec Settlement

Orthotec Settlement	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Orthotec Settlement	7. Orthotec Settlement On September 26, 2014, the Company entered into a Settlement and Release Agreement, dated as of August 13, 2014, by and among the Company and its direct subsidiaries, including Alphatec Spine, Inc., Alphatec Holdings International C.V., Scient'x S.A.S. and Surgiview S.A.S.; HealthpointCapital, LLC, HealthpointCapital Partners, L.P., HealthpointCapital Partners II, L.P., John H. Foster and Mortimer Berkowitz III; and Orthotec, LLC and Patrick Bertranou, (the “Settlement Agreement”). Pursuant to the Settlement Agreement, the Company agreed to pay Orthotec, LLC $49.0 million in cash, including initial cash payments totaling $1.75 million, which the Company previously paid in March 2014, and an additional lump sum payment of $15.75 million, which the Company previously paid in April 2014. The Company agreed to pay the remaining $31.5 million in 28 quarterly installments of $1.1 million and one additional quarterly installment of $0.7 million, commencing October 1, 2014. The payments set forth above are guaranteed by Stipulated Judgments held against the Company, HealthpointCapital Partners, L.P., HealthpointCapital Partners II, L.P., HealthpointCapital, LLC, John H. Foster and Mortimer Berkowitz III and, in the event of a default, will be entered and enforced against these entities and/or individuals in that order. In September 2014, the Company and HealthpointCapital entered into an agreement for joint payment of settlement whereby HealthpointCapital has agreed to contribute $5.0 million to the $49.0 million settlement amount. In October 2020, began its $5.0 million contribution, which will be in the form of quarterly payments. classified within stockholders’ equity on the Company’s consolidated balance sheets due to the related party nature with HealthpointCapital affiliates. Payments made by HealthpointCapital will be recorded as a reduction to stockholder’s equity. See Note 11 for further information. As of December 31, 2020, the Company has made installment payments in the aggregate of $45.0 million, with a remaining outstanding balance of $12.8 million (including interest). The Company has the right to prepay the amounts due without penalty. The unpaid amounts due accrue interest at the rate of 7.0% per year until paid in full. The accrued but unpaid interest will be paid in quarterly installments of $1.1 million (or the full amount of the accrued but unpaid interest if less than $1.1 million) following the full payment of the $31.5 million in quarterly installments described above. No interest will accrue on the accrued interest. The Settlement Agreement provides for mutual releases of all claims in the Orthotec, LLC v. Surgiview, S.A.S, et al. matter in the Superior Court of California, Los Angeles County and all other related litigation matters involving the Company and its directors and affiliates. A reconciliation of the total net settlement obligation is as follows (in thousands): December 31, 2020 December 31, 2019 Litigation settlement obligation - short-term portion $ 4,000 $ 4,400 Litigation settlement obligation - long-term portion 7,634 10,712 Total 11,634 15,112 Future Interest 1,199 2,121 Total settlement obligation, gross 12,833 17,233 Related party receivable - included in stockholders' equity (4,000 ) (5,000 ) Total settlement obligation, net $ 8,833 $ 12,233

Equity

Equity	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Equity	8. Equity Follow-On Registered Public Offering On October 16, 2020, the Company closed the 2020 Offering where it issued and sold a total of 13,142,855 shares of its common stock. The shares were sold pursuant to the Underwriting Agreement between the Company and Morgan Stanley & Co. LLC and Cowen and Company, LLC, as representative of the several underwriters named therein, at a price to the public of $8.75 per share. The closing of the 2020 Offering included the issuance and sale of 1,714,285 shares of the Company’s common stock, included within the total number of shares above, pursuant to the full exercise of the underwriters’ option to purchase additional shares pursuant to the Underwriting Agreement. The net proceeds to the Company from the 2020 Offering were approximately $107.7 million, including the net proceeds from the overallotment shares and deducting underwriting discounts and commissions and estimated offering expenses payable by the Company. Redeemable Preferred Stock The Company issued shares of redeemable preferred stock in connection with its initial public offering in June 2006. As of December 31, 2020, and 2019, the redeemable preferred stock carrying value was $23.6 million and there were 20 million shares of redeemable preferred stock authorized. The redeemable preferred stock is not convertible into common stock but is redeemable at $9.00 per share, (i) upon the Company’s liquidation, dissolution or winding up, or the occurrence of certain mergers, consolidations or sales of all or substantially all of the Company’s assets, before any payment to the holders of the Company’s common stock, or (ii) at the Company’s option at any time. Holders of redeemable preferred stock are generally not entitled to vote on matters submitted to the stockholders, except with respect to certain matters that will affect them adversely as a class and are not entitled to receive dividends. The carrying value of the redeemable preferred stock was $7.11 per share at December 31, 2020 and 2019. The redeemable preferred stock is presented separately from stockholders’ equity in the consolidated balance sheets and any adjustments to its carrying value up to its redemption value of $9.00 per share are reported as a dividend. 2017 PIPE Warrants The 2017 Common Stock Warrants (the “2017 PIPE Warrants”) have a five-year there were 543,864 2017 PIPE Warrant exercises, for total cash proceeds of $1.1 million. 2018 PIPE Warrants The 2018 Common Stock Warrants (the “2018 PIPE Warrants”) have a five-year year ended December 31, 2020, there were 2,342,986 2018 PIPE Warrant exercises for total cash proceeds of $1.3 million. During the year ended , there were 274,180 2018 PIPE Warrant exercises for total cash proceeds of $0.6 million. December 31, 2020 SafeOp Surgical Merger Warrants In conjunction with the Company’s 2018 acquisition of SafeOp, the Company issued warrants to purchase 2,200,000 shares of common stock at an exercise price of $3.50 per share and contain a five-year Squadron Medical Warrants As further described in Note 5, during the year ended December 31, 2018, in connection with the initial debt financing with Squadron Medical and a participant lender, the Company issued warrants to purchase 845,000 shares of common stock at an exercise price of $3.15 per share. An additional 4,838,710 warrants were issued at an exercise price of $2.17 per share during the second quarter of 2019, in conjunction with the Company’s draw on the expanded credit facility. In May 2020, an additional 1,075,820 warrants were issued at an exercise price of $4.88 per share in conjunction with the Company’s second amendment to the Squadron Medical debt for total warrants outstanding to Squadron Medical and the participant lender of 6,759,530. The warrants have a seven-year Executive Warrants In December 2017 the Company issued warrants to Mr. Miles, the Company’s Chairman and Chief Executive Officer, to purchase 1,327,434 shares of the Company’s common stock for $5 per share. The warrants have a five-year A summary of all outstanding warrants is as follows (in thousands): Number of Warrants Strike Price Expiration 2017 PIPE Warrants 3,107 $ 2.00 June 2022 2018 PIPE Warrants 11,380 $ 3.50 May 2023 SafeOp Surgical Merger Warrants 2,165 $ 3.50 May 2023 2018 Squadron Medical Warrants 845 $ 3.15 May 2027 2019 Squadron Medical Warrants 4,839 $ 2.17 May 2027 2020 Squadron Medical Warrants 1,076 $ 4.88 May 2027 Executive Warrants 1,327 $ 5.00 December 2022 Other* 142 $ 3.85 Various through May 2023 Total 24,881 *Represents weighted average strike price

Stock Benefit Plans and Stock-B

Stock Benefit Plans and Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Benefit Plans and Stock-Based Compensation	9. Stock Benefit Plans and Stock-Based Compensation 2016 Equity Incentive Plan In the third quarter of 2016, the Company adopted its 2016 Equity Incentive Plan (the “2016 Plan”), which replaced the Company’s 2005 Employee, Director and Consultant Stock Plan. On October 25, 2018, the Company’s Board of Directors adopted an amendment to the Company’s 2016 Equity Incentive Award Plan. The 2016 Plan allows for the grant of options, restricted stock, restricted stock unit awards and performance unit awards to employees, directors, and consultants of the Company. Upon its adoption, the 2016 Plan had 1,083,333 shares of common stock reserved for issuance. The Board of Directors determines the terms of the grants made under the 2016 Plan. Options granted under the 2016 Plan expire no later than ten years from the date of grant (five years for incentive stock options granted to holders of more than 10% of the Company’s voting stock). Options generally vest over a four-year Salary-to-Equity Conversion Program On April 5, 2020, the Company implemented a voluntary salary-to-equity conversion program for certain employees whose annual payroll costs exceed $100,000, including the Company’s executive officers. The program permitted each participant to make a voluntary election to reduce the participant’s compensation rate through July 11, 2020 from 10% to 75%. In exchange for the compensation reduction, each participant was granted a restricted stock unit from the Company’s 2016 Equity Incentive Plan, equal to the dollar amount of compensation reduction divided by the 30-day volume weighted average price of the Company’s common stock as of close of market on April 3, 2020. The restricted stock units granted under the program fully vested on July 10, 2020. The temporary reduction in compensation to the participants shall not be treated as a reduction in base annual salary rate for purposes of any other benefits plans in which the participants are enrolled or eligible to participate, including in any bonus plans of the Company. As the plan allows for a cash payment of the deferred amount in the event the employee separated from the Company prior to the completion date of the program, the amounts were recorded as a liability instrument through its settlement date with a corresponding fair value adjustment at each reporting period. The full fair value of $0.9 million was reclassified into equity upon settlement of the program and issuance of the common stock. A stock compensation charge of $0.9 million related to the program was recorded during the year ended December 31, 2020. 2016 Employment Inducement Award Plan On October 4, 2016, the Company’s Board of Directors adopted the 2016 Employment Inducement Award Plan (the “Inducement Plan”). The Inducement Plan allows for the grant of options, restricted stock, restricted stock unit awards and performance unit awards to new employees of the Company by granting an award to such new employee as an inducement for the employee to begin employment with the Company. As of December 31, 2020 the Inducement Plan had 692,392 shares of common stock reserved for issuance, which may only be granted to an employee who has not previously been an employee or member of the board of directors of the Company. The terms of the Inducement Plan are substantially similar to the terms of the Company’s 2016 Plan with two principal exceptions: (i) incentive stock options may not be granted under the Inducement Plan; and (ii) the annual compensation paid by the Company to specified executives will be deductible only to the extent that it does not exceed $1.0 million. 2019 Management Objective Strategic Incentive Plan Under the 2019 Management Objective Strategic Incentive Plan, the Company is authorized to grant up to 500,000 shares of common stock to third-party individuals or entities that do not qualify under the Company’s other existing equity plans, with a maximum grant of 50,000 shares per participant. As of December 31, 2020, 130,000 restricted shares and a warrant to purchase up to 25,000 restricted common stock shares have been granted under the 2019 Management Objective Strategic Incentive Plan. Total expense for the plan was $0.2 million and an immaterial amount for the years ended December 31, 2020 and December 31, 2019, respectively. 2017 Distributor Inducement Plan and 2017 Development Services Plan Under the 2017 Distributor Inducement Plan, the Company is authorized to grant up to 1,000,000 shares of common stock to third-party distributors whereby, upon the achievement of certain Company sales and/or distribution milestones the Company may grant to a distributor shares of common stock or warrants to purchase shares of common stock. The warrants and restricted stock units issued under the plan are subject to time based or net sales-based vesting conditions. As of December 31, 2020, 525,000 warrants and 284,500 shares of restricted common stock were granted under the 2017 Distributor Inducement Plan. As of December 31, 2020, 220,000 shares of common stock were earned or issued. Warrants granted under the plan as of December 31, 2020 were not yet subject to expiration related to any time or sales-based vesting conditions. Expense recorded for the plan was $0.5 million and $0.4 million for the years ended December 31, 2020 and December 31, 2019, respectively. Under the 2017 Development Services Plan, the Company is authorized to grant up to 7,000,000 shares of common stock to third-party individuals or entities whereby, upon the achievement of certain Company financial and commercial revenue milestones, future royalty payments for product and/or intellectual property development work may be paid in either cash or restricted shares of Company common stock at the election of the developer. Each common stock issuance is subject to net sales-based and other vesting provisions and satisfaction of applicable laws and market regulations regarding the issuance of restricted shares to such developers. As of December 31, 2020, the Company has entered into Development Services Agreements pursuant to which the Company has allocated 5,769,000 shares and granted 3,190,000 shares of restricted common stock under the 2017 Development Services Plan, subject to achievement of the performance criteria and vesting conditions as set forth in such Development Services Agreements. None of the grants are deemed probable of equity election and no common stock elections or cash payouts have been made under the plan as of December 31, 2020. The Company will recognize a non-cash charge to cost of sales associated with each of the Development Services Agreements when it is probable the respective performance targets will be achieved. Stock Options A summary of the Company’s stock option activity under the Plans and related information is as follows (in thousands, except as indicated and per share data): Shares Weighted average exercise price Weighted average remaining contractual term (in years) Aggregate intrinsic value Outstanding at December 31, 2019 4,215 $ 3.27 Granted 71 $ 6.64 Exercised (241 ) $ 2.33 $ 2,253 Forfeited (94 ) $ 10.44 Outstanding at December 31, 2020 3,951 $ 3.21 6.93 $ 45,320 Options vested and exercisable at December 31, 2020 2,837 $ 3.26 6.70 $ 32,570 Options vested and expected to vest at December 31, 2020 3,951 $ 3.21 6.93 $ 45,320 The weighted-average grant-date fair value per share of stock options granted during the years ended December 31, 2020 and 2019 was $4.71 and $1.92, respectively. The aggregate intrinsic value of options at December 31, 2020 is based on the Company’s closing stock price on the last business day of 2020 of $14.52 per share. As of December 31, 2020, there was $2.2 million of unrecognized compensation expense for stock options which is expected to be recognized on a straight-line basis over a weighted average period of approximately 1.57 years. Restricted Stock Awards and Units The following table summarizes information about the restricted stock awards, restricted stock units and performance-based restricted units activity (in thousands, except as indicated and per share data): Shares Weighted average grant date fair value Weighted average remaining recognition period (in years) Unvested at December 31, 2019 6,727 $ 2.17 Awarded 3,964 $ 4.87 Vested (2,363 ) $ 3.52 Forfeited (112 ) $ 4.13 Unvested at December 31, 2020 8,216 $ 3.13 1.99 The weighted average fair value per share of awards granted during the years ended December 31, 2020 and 2019 was $4.87 and $1.92, respectively. As of December 31, 2020, there was $22.1 million of unrecognized compensation expense for restricted stock awards and units which is expected to be recognized on a straight-line basis over a weighted average period of approximately 1.99 years. Employee Stock Purchase Plan In 2007, the Company adopted the Alphatec Holdings, Inc. 2007 Employee Stock Purchase Plan (the “ESPP”), which was amended in May 2017. The ESPP provides eligible employees with a means of acquiring equity in the Company at a discounted purchase price using their own accumulated payroll deductions. Under the terms of the ESPP, employees can elect to have up to 20% of their annual compensation, up to a maximum of $21,250 per year, withheld to purchase shares of Company common stock for a purchase price equal to 85% of the lower of the fair market value per share (at closing) of Company common stock on (i) the commencement date of the six-month During the years ended December 31, 2020 and 2019, there were 379,166 and 359,689 shares of common stock, respectively, purchased under the ESPP. The Company recognized $1.0 million and $0.7 million in expense related to the ESPP for the years ended December 31, 2020 and 2019, respectively. As of December 31, 2020, 216,131 shares were available under the ESPP for future issuance. The Company estimates the fair value of shares issued to employees under the ESPP using the Black-Scholes option-pricing model Year Ended December 31, 2020 2019 Risk-free interest rate 0.12% - 1.58% 1.58% - 2.50% Expected dividend yield — — Expected term (years) 0.50 0.50 Volatility 54.96%-102.50% 49.78%-82.08% Common Stock Reserved for Future Issuance Common stock reserved for future issuance consists of the following (in thousands): December 31, 2020 Warrants outstanding 24,881 Authorized for future grant under the Plans 5,015 Authorized for future grant under the Management Objective Strategic Incentive Plan 345 Authorized for future grant under the Distributor and Development Services plans 7,780 Stock options outstanding 3,951 Unvested restricted stock awards 8,216 Employee stock purchase plan 216 Series A convertible preferred stock 29 50,433

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes The components of the pretax income (loss) are presented in the following table (in thousands): Year Ended December 31, 2020 2019 U.S. Domestic $ (78,849 ) $ (57,141 ) Foreign — (100 ) Pretax loss from operations $ (78,849 ) $ (57,241 ) The components of the provision (benefit) for income taxes from continuing operations are presented in the following table (in thousands): Year Ended December 31, 2020 2019 Current income tax provision: Federal $ — $ — State 100 207 Foreign 35 — Total current 135 207 Deferred income tax (benefit) provision: Federal (2 ) (195 ) State 12 (251 ) Total deferred 10 (446 ) Total income tax provision (benefit) $ 145 $ (239 ) The provision for income taxes differs from the amount of income tax determined by applying the applicable U.S. statutory federal income tax rate to pretax loss from continuing operations as a result of the following differences: December 31, 2020 2019 Federal statutory rate 21.00 % 21.00 % Adjustments for tax effects of: State taxes, net (0.11 )% 0.12 % Stock-based compensation (0.93 )% 0.26 % R&D credit expiration - % (5.96 )% Foreign taxes (0.04 )% - % Other permanent adjustments (1.70 )% (0.42 )% Foreign partnership liquidation - % 19.19 % Federal uncertain tax positions - % 3.25 % NOL expiration - % (3.01 )% Other (0.15 )% 1.16 % Valuation allowance (18.25 )% (35.09 )% Effective income tax rate (0.18 )% 0.50 % Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2020 and 2019 are as follows (in thousands): December 31, 2020 2019 Deferred tax assets: Accruals and reserves $ 3,665 $ 2,730 Income tax credit carryforwards 1,582 1,591 Interest 8,193 4,095 Inventory 8,117 8,625 Legal settlement 2,875 3,789 Net operating losses 70,220 53,592 Stock-based compensation 2,464 2,256 Total deferred tax assets 97,116 76,678 Valuation allowance (87,489 ) (71,159 ) Total deferred tax assets, net of valuation allowance 9,627 5,519 Deferred tax liabilities: Property and equipment (7,094 ) (3,117 ) Goodwill and intangibles (2,483 ) (2,344 ) Total deferred tax liabilities (9,577 ) (5,461 ) Net deferred tax assets $ 50 $ 58 The realization of deferred tax assets is dependent on the Company’s ability to generate sufficient taxable income in future years in the associated jurisdiction to which the deferred tax assets relate. As of December 31, 2020, a valuation allowance of $87.5 million has been established against the deferred tax assets, as the Company has determined that it is currently not likely that these assets will be realized. During the years ended December 31, 2020, the federal and state valuation allowances collectively increased by $14.4 million and $1.9 million, respectively. In determining the need for a valuation allowance, the Company considers all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies, and recent financial performance. Based on the review of all positive and negative evidence, including a three-year At December 31, 2020, the Company has unrecognized tax benefits of $2.5 million which will affect the effective tax rate if recognized when the Company no longer has a valuation allowance offsetting its deferred tax assets. The following table summarizes the changes to unrecognized tax benefits (in thousands): Year ended December 31, 2020 2019 Unrecognized tax benefit at the beginning of the year $ 2,452 $ 4,334 Reductions as a result of lapse of applicable statute of limitations — (1,882 ) Unrecognized tax benefits at the end of the year $ 2,452 $ 2,452 The Company and its subsidiaries are subject to federal income tax as well as income tax of multiple state and foreign jurisdictions. With few exceptions, the Company is no longer subject to income tax examination by tax authorities in major jurisdictions for years prior to 2015. However, to the extent allowed by law, the taxing authorities may have the right to examine prior periods where net operating losses and tax credits were generated and carried forward and make adjustments up to the amount of the carryforwards. The Company is not currently under examination by the Internal Revenue Service, foreign or state and local tax authorities. The Company recognizes interest and penalties related to uncertain tax positions as a component of the income tax provision. As of December 31, 2020, there were no accrued interest and penalties. At December 31, 2020, the Company had federal and state net operating loss carryforwards of $273.7 million and $193.4 million, respectively, which began expiring at various dates beginning in 2021 and through 2040. Federal and some state net operating losses generated in years ending after December 31, 2017 can be carried forward indefinitely. At December 31, 2020, the Company had state research and development tax credit carryforwards of $3.2 million. The state research and development tax credits do not have an expiration date and may be carried forward indefinitely. Utilization of the net operating loss and tax credit carryforwards may become subject to annual limitations due to ownership change limitations that could occur in the future as provided by Section 382 and 383 of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”), as well as similar state provisions. These ownership changes may limit the amount of the net operating loss and tax credit carryforwards that can be utilized annually to offset future taxable income, if the Company experiences a cumulative change in ownership of more than 50% within a three-year

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	11. Related Party Transactions In July 2016, the Company entered into a forbearance agreement with HealthpointCapital, LLC, HealthpointCapital Partners, L.P., and HealthpointCapital Partners II, L.P. (collectively, "HealthpointCapital"), pursuant to which HealthpointCapital, on behalf of the Company, paid $1.0 million of the $1.1 million payment due and payable by the Company to Orthotec on July 1, 2016 and agreed to not exercise its contractual rights to seek an immediate repayment of such amount. Pursuant to this forbearance agreement, the Company repaid this amount in September 2016. The Company and HealthpointCapital also entered into an agreement for joint payment of settlement whereby HealthpointCapital has agreed to contribute $5.0 million to the $49.0 million Orthotec settlement amount. In October 2020, began making its $5.0 million contribution, which will be in the form of quarterly payments. During the second quarter of 2018, HealthpointCapital Partners, L.P., and HealthpointCapital Partners II, L.P. distributed its holdings in the Company’s common stock to its limited partners. As a result, the fund is no longer a shareholder of the Company as of December 31, 2020 HealthpointCapital classified within stockholders’ equity on the Company’s consolidated balance sheets due to the related party nature with HealthpointCapital affiliates. Payments made by HealthpointCapital will be recorded as an increase to stockholder’s equity. In November 2018, the Company entered into a Term Loan with Squadron Medical. The Term Loan was amended in March 2019, May 2020 and December 2020. See Note 5 for further details regarding the Term Loan. Squadron Capital, LLC, an affiliate of Squadron Medical, was a lead investor in the Private Placement that was closed on March 1, 2021. David Pelizzon, President and Director of Squadron Capital, LLC, currently serves on the Company’s Board of Directors. Included on the consolidated balance sheet as of December 31, 2020 is a $1.1 million officer receivable for settlement of a tax liability related to the vesting of a restricted stock unit. A corresponding liability for the same amount is also included on the consolidated balance sheet within the accrued expenses line item. Subsequent to December 31, 2020, the amounts were remitted to settle the tax liability.

Retirement Plan

Retirement Plan	12 Months Ended
	Dec. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Retirement Plan	12. Retirement Plan The Company maintains an employee savings plan that qualifies as a deferred salary arrangement under Section 401(k) of the Internal Revenue Code. Under the savings plan, participating employees may contribute a portion of their pre-tax earnings, up to the Internal Revenue Service annual contribution limit. Additionally, the Company may elect to make matching contributions into the savings plan at its sole discretion of up to 4% of each individual’s compensation. Matching contributions vest after one year of service. The Company’s total contributions to the 401(k) plan were $0.9 million and $0.6 million for the years ended December 31, 2020 and 2019, respectively.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Events On March 5, 2021, the Company filed a draft offer with the AMF related to its Tender Offer Agreement with EOS to purchase all of the issued and outstanding EOS Shares and OCEANEs. The Tender Offer Agreement is subject to clearance by the French Ministry of the Economy and Finance and AMF and will consist of a cash tender offer price of €2.45 (or approximately $2.99) per EOS Share and €7.01 (or approximately $8.55) per OCEANE for a total purchase price of up to approximately $116.9 million. Once approved, the Offer will be open for tender during an initial acceptance period of 25 Euronext Paris trading days. The obligation of the Company or its affiliates to purchase EOS Shares and OCEANEs pursuant to the Offer is subject to the satisfaction or waiver of the condition that a minimum number of EOS Shares and OCEANEs have been validly tendered that would allow the Company to acquire at least two-thirds of the share capital and voting rights of EOS on a fully diluted basis at the end of the acceptance period of the Offer. The settlement and delivery of the EOS Shares and OCEANEs tendered into the Offer will occur shortly after the end of the initial acceptance period of the Offer. The Offer will then reopen for a subsequent acceptance period of 10 Euronext Paris trading days. If the Company or its affiliates own 90% or more of EOS’ share capital and voting rights upon closing of the initial or subsequent offer acceptance period, In connection with the proposed acquisition of EOS in December 2020, the Company announced a definitive securities purchase agreement to raise $138.0 million in a private placement of common stock at a price of $11.11 per share. The Private Placement , which closed on March 1, 2021, generated net proceeds of approximately $132.0 million, net of fees related to the Private Placement

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, and the reported amounts of revenues and expenses. Actual results could differ from those estimates. Significant items subject to such estimates and assumptions include the useful lives of property and equipment, intangibles, allowances for doubtful accounts, the valuation of share-based liabilities, deferred tax assets, inventory, stock-based compensation, revenues, restructuring liabilities, income tax uncertainties, and other contingencies.
Concentrations of Credit Risk and Significant Customers	Concentrations of Credit Risk and Significant Customers Financial instruments, which potentially subject the Company to concentrations of credit risk, consist primarily of cash and accounts receivable. The Company limits its exposure to credit loss by depositing its cash with established financial institutions. As of December 31, 2020, a substantial portion of the Company’s available cash funds is held in business accounts. Although the Company deposits its cash with multiple financial institutions, its deposits, at times, may exceed federally insured limits. The Company’s customers are primarily hospitals, surgical centers and distributors. No one single customer represented greater than 10 percent of consolidated revenues and accounts receivable for any of the years presented. Credit to customers is granted based on an analysis of the customers’ credit worthiness. Credit losses have not been significant.
Accounts Receivable, net	Accounts Receivable, net Accounts receivable are presented net of allowance for doubtful accounts. The Company makes judgments as to its ability to collect outstanding receivables and provides allowances for a portion of receivables when collection becomes doubtful. Provisions are made based upon a specific review of all significant outstanding invoices and the overall quality and age of those invoices not specifically reviewed. In determining the provision for invoices not specifically reviewed, the Company analyzes historical collection experience. If the historical data used to calculate the allowance provided for doubtful accounts does not reflect the Company’s future ability to collect outstanding receivables or if the financial condition of customers were to deteriorate, resulting in impairment of their ability to make payments, an increase in the provision for doubtful accounts may be required. The Company’s accounts year
Inventories, net	Inventories, net Inventories are stated at the lower of cost or net realizable value, with cost primarily determined under the first-in, first-out method. The Company reviews the components of inventory on a periodic basis for excess, obsolete and impaired inventory, and records a reserve for the identified items. The Company calculates an inventory reserve for estimated excess and obsolete inventory based upon historical turnover and assumptions about future demand for its products and market conditions. The Company’s biologics inventories have an expiration based on a shelf life and are subject to demand fluctuations based on the availability and demand for alternative implant products. The Company’s estimates and assumptions for excess and obsolete inventory are reviewed and updated on a quarterly basis. Increases in the reserve for excess and obsolete inventory result in a corresponding increase to cost of revenues and establish a new cost basis for the part.
Property and Equipment, net	Property and Equipment, net Property and equipment are stated at cost, net of accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the related assets, generally ranging from three to seven years. Leasehold improvements and assets acquired under capital leases are amortized over the shorter of their useful lives or the remaining terms of the related leases.
Operating Lease	Operating Lease Effective January 1, 2019, the Company adopted ASC No. 2016‑02, Leases (Topic 842) (“ASC 842”) On December 4, 2019, the Company entered into a new lease agreement, (“New Building Lease”), for a new headquarters location in Carlsbad, California. The term of the New Building Lease commenced on February 1, 2021 and at time of lease commencement the Company applied this guidance to create an additional ROU asset and operating lease liability on the Company’s consolidated balance sheet. Rent expense for operating leases is recognized on a straight-line basis over the reasonably assured lease term based on the total lease payments and is included in research and development and general and administrative expenses in the consolidated statements of operations.
Goodwill and Intangible Assets	Goodwill and Intangible Assets The Company’s goodwill represents the excess of the cost over the fair value of net assets acquired from its business combination with SafeOp. The determination of the value of goodwill and intangible assets arising from its business combination and asset acquisitions requires extensive use of accounting estimates and judgments to allocate the purchase price to the fair value of the net tangible and intangible assets acquired, including capitalized Intangible assets acquired in a business combination that are used for IPR&D are considered indefinite lived until the completion or abandonment of the associated research and development efforts. Upon reaching the end of the relevant research and development project, the Company will amortize the acquired IPR&D over its estimated useful life or expense the acquired IPR&D should the research and development project be unsuccessful with no future alternative use. Goodwill and IPR&D are not amortized; however, they are assessed for impairment using fair value measurement techniques on an annual basis or more frequently if facts and circumstance warrant such a review. The goodwill or IPR&D are considered to be impaired if the Company determines that the carrying value of the reporting unit or IPR&D exceeds its respective fair value. The Company performs its annual impairment analysis by comparing the Company’s estimated fair value, calculated from t he Company’s market capitalization, The Company completed its most recent annual evaluation for impairment as of December 31, 2020 and determined that no impairment existed and, consequently, no impairment charge has been recorded during the year Intangible assets with a finite life, such as acquired technology, customer relationships, manufacturing know-how, licensed technology, supply agreements and certain trade names and trademarks, are amortized on a straight-line basis over their estimated useful life, ranging from one to twenty-year The Company evaluates its intangible assets with finite lives for indications of impairment whenever events or changes in circumstances indicate that the carrying value may not be recoverable. Factors that could trigger an impairment review include significant under-performance relative to expected historical or projected future operating results, significant changes in the manner of the Company’s use of the acquired assets or the strategy for the Company’s overall business or significant negative industry or economic trends. If this evaluation indicates that the value of the intangible asset may be impaired, the Company makes an assessment of the recoverability of the net carrying value of the asset over its remaining useful life. If this assessment indicates that the intangible asset is not recoverable, based on the estimated undiscounted future cash flows of the technology over the remaining amortization period, the Company reduces the net carrying value of the related intangible asset to fair value and may adjust the remaining amortization period. There were no impairment charges during the years ended December 31, 2020 or 2019.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company assesses potential impairment to its long-lived assets when there is evidence that events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. An impairment loss is recognized when the carrying amount of the long-lived assets is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. Any required impairment loss is measured as the amount by which the carrying amount of a long-lived asset exceeds its fair value and is recorded as a reduction in the carrying value of the related asset and a charge to operating results. There were no impairment charges during the years ended December 31, 2020 or 2019.
Warrants to Purchase Common Stock	Warrants to Purchase Common Stock Warrants are accounted for in accordance with the applicable accounting guidance as either derivative liabilities or as equity instruments depending on the specific terms of the agreements. Liability-classified instruments are recorded at fair value at each reporting period with any change in fair value recognized as a component of change in fair value of derivative liabilities in the consolidated statements of operations. All warrants issued in 2020 and 2019 qualified for classification within stockholders’ equity and, therefore, did not require liability accounting.
Fair Value Measurements	Fair Value Measurements The carrying amount of financial instruments consisting of cash, trade accounts receivable, prepaid expenses and other current assets, accounts payable, accrued expenses, accrued compensation and current portion of long-term debt included in the Company’s consolidated financial statements are reasonable estimates of fair value due to their short maturities. Based on the borrowing rates currently available to the Company for loans with similar terms, management believes the fair value of long-term debt approximates its carrying value. Authoritative guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Level 2: Level 3: T he Company does not maintain any financial assets that are considered to be Level 1, Level 2 or Level 3 instruments as of the years ended December 31, 2020 or December 31,2019. Liabilities measured Balance at Year Ended December 31, 2020 Level 1 Level 2 Level 3 Liability classified equity award* $ 4,108 — — $ 4,108 Foreign currency forward contract $ 878 — $ 878 — Balance at Year Ended December 31, 2019 Level 1 Level 2 Level 3 Liability classified equity award* $ 1,705 — — $ 1,705 *a portion of this liability is being accreted over the requisite service period On December 18, 2020, the Company entered into a foreign currency forward contract, with a notional amount of $117.9 million to mitigate the foreign currency exchange risk related to the Company’s Tender Offer Agreement, denominated in Euros ("EUR"). The contract is not designated as a hedging instrument. The Company has classified the derivative liability within Level 2 of the fair value hierarchy as observable inputs are available for the full term of the derivative instrument. The fair value of the forward contract was developed using a market approach based on publicly available market yield curves and the term of the contract. For the year ended December 31, 2020, the Company recognized a $0.9 million loss from the change in fair value of the contract, which was included in other expense, net in the consolidated statement of operations. A corresponding liability of $0.9 million related to the forward contract was included in accrued expenses on the Company’s consolidated balance sheet as of December 31, 2020. In 2019, the fair value of the contingent consideration liability assumed in the SafeOp acquisition was recorded as part of the purchase price consideration of the acquisition. The contingent consideration related to the SafeOp acquisition was classified within Level 3 of the fair value hierarchy as the Company was using a probability-weighted income approach, utilizing significant unobservable inputs including the probability of achieving each of the potential milestones and an estimated discount rate related to the risks of the expected cash flows attributable to the milestones. All the contingent milestones were achieved as of December 31, 2019. During the year ended December 31, 2019, the Company achieved the second of the two milestones related to the acquisition of SafeOp, which was settled through the issuance of 886,843 shares of the Company’s common stock. During the second quarter of 2019, the Company issued a liability classified equity award to one of its executive officers. The award will be earned over a 4-year vesting period and upon a specific market condition. As the award will be cash settled, it is classified as a liability within Level 3 of the fair value hierarchy as the Company is using a probability-weighted income approach, utilizing significant unobservable inputs including the probability of achieving the specified market condition with the valuation updated at each reporting period. The full fair value of the cash settled award was $ 4.1 million and $ 1.7 million as of December 31, 2020 and December 31, 2019, respectively. The fair value of the award is being recognized ratably as the underlying service period is provided . The following table provides a reconciliation of liabilities measured at fair value on a recurring basis as of December and Level 3 Liabilities Balance at December 31, 2018 $ 2,600 Settlement of milestone #2 (2,889 ) Change in fair value measurement- milestone #2 289 Straight line recognition of liability classified equity award 173 Change in fair value measurement of liability classified equity award 93 Balance at December 31, 2019 266 Straight line recognition of liability classified equity award 371 Change in fair value measurement of liability classified equity award 1,031 Balance at December 31, 2020 $ 1,668
Revenue Recognition	Revenue Recognition The Company recognizes revenue from product sales in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers The Company derives its revenues primarily from the sale of spinal surgery implants and products used in the treatment of spine disorders. The Company sells its products primarily through its direct sales force and independent distributors. Revenue is recognized when control of the promised goods is transferred to the customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods. Transfer of control generally occurs when the Company receives the written acknowledgment that the product has been used in a surgical procedure or upon shipment to third-party customers who immediately accept title to such product.
Research and Development Expenses	Research and Development Expenses Research and development expenses consist of costs associated with the design, development, testing, and enhancement of the Company’s products and technologies. Research and development costs also include salaries and related employee benefits, research-related overhead expenses, and fees paid to external service providers. Research and development costs are expensed as incurred.
Litigation-related Expenses	Litigation-related Expenses Litigation-related expenses are costs incurred for the ongoing litigation, primarily with NuVasive, Inc . See Note 6 for further information.
Transaction-related Expenses	Transaction-related Expenses The Company expensed certain costs incurred throughout the year related to the prior tender offer agreement entered into with EOS on February 28, 2020, which was subsequently terminated by the Company in response to the then-expected market effects of the COVID-19 pandemic on April 24, 2020, as well as costs incurred related to the renewed tender offer agreement entered into with EOS on December 16, 2020. These expenses primarily include third-party advisory and legal fees .
Product Shipment Cost	Product Shipment Cost Product shipment costs are included in sales and marketing expenses in the accompanying consolidated statements of operations. Product shipment costs totaled $5.3 million and $4.0 million for the years ended December 31, 2020 and 2019, respectively.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for stock-based compensation under provisions which require that share-based payment transactions with employees be recognized in the financial statements based on their fair value and recognized as compensation expense over the vesting period. The amount of expense recognized during the period is affected by subjective assumptions, including estimates of the future volatility of the Company’s stock price, the expected term for its stock options, the number of options expected to ultimately vest, and the timing of vesting for the Company’s share-based awards. The Company uses a Black-Scholes option pricing valuation model to estimate the fair value of its stock option awards. The calculation of the fair value of the awards using the Black-Scholes option pricing model is affected by the Company’s common stock price on the date of grant as well as assumptions regarding the following: • Estimated volatility is a measure of the amount by which the Company’s common stock price is expected to fluctuate each year during the expected life of the award. The Company’s estimated volatility through December 31, 2020 was based on a weighted-average volatility of its actual historical volatility over a period equal to the expected life of the awards. • The expected term represents the period of time that awards granted are expected to be outstanding. Through December 31, 2020, the Company calculated the expected term using a weighted-average term based on historical exercise patterns and the term from option date to full exercise for the options granted within the specified date range. • The risk-free interest rate is based on the yield curve of a zero-coupon U.S. Treasury bond on the date the stock option award is granted with a maturity equal to the expected term of the stock option award. • The assumed dividend yield is based on the Company’s expectation of not paying dividends in the foreseeable future. The Company uses historical data to estimate the number of future stock option forfeitures. Stock-based compensation recorded in the Company’s consolidated statements of operations is based on awards expected to ultimately vest and has been reduced for estimated forfeitures. The Company’s estimated forfeiture rates may differ from its actual forfeitures which would affect the amount of expense recognized during the period. The Company accounts for stock option grants to non-employees in accordance with provisions which require that the fair value of these instruments be recognized as an expense over the period in which the related services are rendered. Stock-based compensation expense of awards with performance conditions is recognized over the period from the date the performance condition is determined to be probable of occurring through the time the applicable condition is met. Determining the likelihood and timing of achieving performance conditions is a subjective judgment made by management which may affect the amount and timing of expense related to these share-based awards. Share-based compensation is adjusted to reflect the value of options which ultimately vest as such amounts become known in future periods. Stock-based awards with market conditions are valued using the Monte Carlo valuation technique which requires management to make significant estimates and assumptions that are not observable from the market. Stock based compensation for awards with both service and market conditions that contain one vesting date are recognized on a straight-line basis over the longer of the derived service period or the requisite service period. For awards with both service and market conditions with various vesting dates, stock-based compensation is recognized utilizing an accelerated expense model over the longer of the derived service period or the requisite service period.
Valuation of Stock Option Awards	Valuation of Stock Option Awards The weighted average assumptions used to compute the stock-based compensation costs for the stock options granted during the years ended December 31, 2020 and 2019 are as follows: Year Ended December 31, 2020 2019 Risk-free interest rate 1.03 % 2.00 % Expected dividend yield — — Weighted average expected life (years) 6.08 6.09 Volatility 84.00 % 80.76 %
Stock-Based Compensation Costs	Stock-Based Compensation Costs The compensation cost that has been included in the Company’s consolidated statements of operations for all stock-based compensation arrangements is detailed as follows (in thousands): Year Ended December 31, 2020 2019 Cost of revenues $ 512 $ 146 Research and development 2,114 752 Sales, general and administrative 15,033 10,058 Total $ 17,659 $ 10,956
Income Taxes	Income Taxes The Company accounts for income taxes in accordance with provisions which set forth an asset and liability approach that requires the recognition of deferred tax assets and deferred tax liabilities for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of assets and liabilities. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. In making such determination, a review of all available positive and negative evidence must be considered, including scheduled reversal of deferred tax liabilities, projected future taxable income, tax planning strategies, and recent financial performance. The Company recognizes interest and penalties related to uncertain tax positions as a component of the income tax provision.
Net Loss per Share	Net Loss per Share Basic earnings per share (“EPS”) is calculated by dividing the net income or loss available to common stockholders by the weighted average number of shares of common stock outstanding for the period without consideration for common stock equivalents. Diluted EPS is computed by dividing the net income or loss available to common stockholders by the weighted average number of shares of common stock outstanding for the period and the weighted average number of dilutive common stock equivalents outstanding for the period determined using the treasury-stock method. For purposes of this calculation, common stock subject to repurchase by the Company, common stock issuable upon conversion of preferred shares, options and warrants are considered to be common stock equivalents and are only included in the calculation of diluted earnings per share when their effect is dilutive. The following table sets forth the computation of basic and diluted loss per share (in thousands, except per share data): Year Ended December 31, 2020 2019 Numerator: Net loss, basic and diluted $ (78,994 ) $ (57,002 ) Denominator: Weighted average common shares outstanding 67,200 52,520 Weighted average unvested common shares subject to repurchase (180 ) (286 ) Weighted average common shares outstanding - basic and diluted 67,020 52,234 Net loss per share, basic and diluted $ (1.18 ) $ (1.09 ) The anti-dilutive securities not included in diluted net loss per share were as follows calculated on a weighted average basis (in thousands): Year Ended December 31, 2020 2019 Options to purchase common stock 3,951 4,215 Warrants to purchase common stock 24,881 26,557 Series A convertible preferred stock 29 67 Unvested restricted stock awards 8,216 6,727 37,077 37,566
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently Adopted Accounting Pronouncements In December 2019, the Financial Accounting Standards Board (the “FASB”) issued ASU 2019-12, Income Taxes (Topic 740) intended to simplify the accounting for income taxes. The guidance removes the following exceptions: (1) exception to the incremental approach for intraperiod tax allocation when there is a loss from continuing operations and income or a gain from other items, (2) exception to the requirement to recognize a deferred tax liability for equity method investments when a foreign subsidiary becomes an equity method investment, (3) exception to the ability not to recognize a deferred tax liability for a foreign subsidiary when a foreign equity method investment becomes a subsidiary, and (4) exception to the general methodology for calculating income taxes in an interim period when a year-to-date loss exceeds the anticipated loss for the year. Additionally, the guidance simplifies the accounting for income taxes by: (1) requiring that an entity recognize a franchise tax (or similar tax) that is partially based on income as an income-based tax and account for any incremental amount incurred as a non-income-based tax, (2) requiring that an entity evaluate when a step up in the tax basis of goodwill should be considered part of the business combination in which the book goodwill was originally recognized and when it should be considered a separate transaction, (3) specifying that an entity is not required to allocate the consolidated amount of current and deferred tax expense to a legal entity that is not subject to tax in its separate financial statements (although the entity may elect to do so (on an entity-by-entity basis) for a legal entity that is both not subject to tax and disregarded by the taxing authority), (4) requiring that an entity reflect the effect of an enacted change in tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date, and (5) making minor improvements for income tax accounting related to employee stock ownership plans and investments in qualified affordable housing projects accounted for using the equity method. The guidance will be effective for fiscal years and interim periods beginning after December 15, 2020. Different components of the guidance require retrospective, modified retrospective or prospective adoption, and early adoption is permitted . The Company early adopted this standard on January 1, 2020 , and the adoption of the standard did not have a material impact to our consolidated financial statements. In November 2019, the FASB issued Accounting Standards Update (“ASU”) 2019-08, Compensation—Stock Compensation In August 2018, the FASB issued ASU 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40), which aligns the accounting for cloud computing implementation costs with that of costs to develop or obtain internal-use software, meaning such costs that are part of the application development stage are capitalized as an asset and amortized over the term of the arrangement, otherwise, such costs are expensed as incurred. It also clarifies the classification of amounts related to capitalized implementation costs in the financial statements. ASU 2018-15 is effective for annual reporting periods beginning after December 15, 2019, including interim reporting periods within those annual reporting periods. Early adoption is permitted. The Company adopted the guidance effective January 1, 2020. It did not have a material impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other Recently Issued Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40)

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Liabilities measured at fair value on recurring basis	Liabilities measured Balance at Year Ended December 31, 2020 Level 1 Level 2 Level 3 Liability classified equity award* $ 4,108 — — $ 4,108 Foreign currency forward contract $ 878 — $ 878 — Balance at Year Ended December 31, 2019 Level 1 Level 2 Level 3 Liability classified equity award* $ 1,705 — — $ 1,705 *a portion of this liability is being accreted over the requisite service period
Reconciliation of liabilities measured at fair value using significant unobservable inputs	The following table provides a reconciliation of liabilities measured at fair value on a recurring basis as of December and Level 3 Liabilities Balance at December 31, 2018 $ 2,600 Settlement of milestone #2 (2,889 ) Change in fair value measurement- milestone #2 289 Straight line recognition of liability classified equity award 173 Change in fair value measurement of liability classified equity award 93 Balance at December 31, 2019 266 Straight line recognition of liability classified equity award 371 Change in fair value measurement of liability classified equity award 1,031 Balance at December 31, 2020 $ 1,668
Summary of weighted average assumptions used to compute stock-based compensation costs for stock options granted	The weighted average assumptions used to compute the stock-based compensation costs for the stock options granted during the years ended December 31, 2020 and 2019 are as follows: Year Ended December 31, 2020 2019 Risk-free interest rate 1.03 % 2.00 % Expected dividend yield — — Weighted average expected life (years) 6.08 6.09 Volatility 84.00 % 80.76 %
Summary of compensation cost for stock-based compensation arrangements	The compensation cost that has been included in the Company’s consolidated statements of operations for all stock-based compensation arrangements is detailed as follows (in thousands): Year Ended December 31, 2020 2019 Cost of revenues $ 512 $ 146 Research and development 2,114 752 Sales, general and administrative 15,033 10,058 Total $ 17,659 $ 10,956
Computation of Basic and Diluted Loss Per Share	The following table sets forth the computation of basic and diluted loss per share (in thousands, except per share data): Year Ended December 31, 2020 2019 Numerator: Net loss, basic and diluted $ (78,994 ) $ (57,002 ) Denominator: Weighted average common shares outstanding 67,200 52,520 Weighted average unvested common shares subject to repurchase (180 ) (286 ) Weighted average common shares outstanding - basic and diluted 67,020 52,234 Net loss per share, basic and diluted $ (1.18 ) $ (1.09 )
Weighted-average anti-dilutive securities not included in diluted net loss per share	The anti-dilutive securities not included in diluted net loss per share were as follows calculated on a weighted average basis (in thousands): Year Ended December 31, 2020 2019 Options to purchase common stock 3,951 4,215 Warrants to purchase common stock 24,881 26,557 Series A convertible preferred stock 29 67 Unvested restricted stock awards 8,216 6,727 37,077 37,566

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	12 Months Ended
	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Accounts receivable, net	Accounts receivable consist of the following (in thousands): December 31, 2020 2019 Accounts receivable $ 23,887 $ 16,436 Less allowance for doubtful accounts (360 ) (286 ) Accounts receivable, net $ 23,527 $ 16,150
Inventories, net	Inventories consist of the following (in thousands): December 31, 2020 2019 Raw materials $ 6,064 $ 5,822 Work-in-process 1,982 1,578 Finished goods 67,892 51,669 75,938 59,069 Less reserve for excess and obsolete (29,937 ) (24,215 ) Inventories, net $ 46,001 $ 34,854
Property and equipment, net	Property and equipment consist of the following (in thousands, except as indicated): Useful lives December 31, (in years) 2020 2019 Surgical instruments 4 $ 76,669 $ 58,502 Machinery and equipment 7 6,562 6,038 Computer equipment 3 4,206 3,594 Office furniture and equipment 5 1,380 1,297 Leasehold improvements various 1,761 1,761 Construction in progress n/a 2,738 496 93,316 71,688 Less accumulated depreciation and amortization (56,646 ) (51,966 ) Property and equipment, net $ 36,670 $ 19,722
Intangible assets, net	Intangible assets, net consist of the following (in thousands, except as indicated): Remaining Avg. Useful lives Gross Accumulated Intangible December 31, 2020: (in years) Amount Amortization Assets, net Developed product technology 12 $ 35,376 $ (23,056 ) $ 12,320 License agreements 1 5,536 (965 ) 4,571 Trademarks and trade names — 792 (119 ) 673 Customer-related 3 7,458 (3,968 ) 3,490 Distribution network 2 4,027 (1,639 ) 2,388 In process research and development 7 1,278 — 1,278 Total $ 54,467 $ (29,747 ) $ 24,720 Remaining Avg. Useful lives Gross Accumulated Intangible December 31, 2019: (in years) Amount Amortization Assets, net Developed product technology 12 $ 35,376 $ (22,206 ) $ 13,170 Intellectual Property — 1,004 (1,004 ) — License agreements 1 5,536 (740 ) 4,796 Trademarks and trade names — 792 (119 ) 673 Customer-related 4 7,458 (3,481 ) 3,977 Distribution network 3 4,027 (1,438 ) 2,589 In process research and development 7 400 — 400 Total $ 54,593 $ (28,988 ) $ 25,605
Schedule of intangible assets, future expected amortization expense	Future amortization expense related to intangible assets as of December 31, 2020 is as follows (in thousands): Year Ending December 31, 2021 $ 2,014 2022 2,014 2023 2,014 2024 1,911 2025 1,326 Thereafter 15,441 Total $ 24,720
Accrued expenses	Accrued expenses consist of the following (in thousands): December 31, 2020 2019 Commissions and sales milestones $ 6,734 $ 5,299 Payroll and payroll related 12,247 7,949 Litigation settlement obligation - short-term portion 4,000 4,400 Professional fees 3,551 3,945 Royalties 2,293 1,981 Interest 619 155 Other 5,787 2,687 Total accrued expenses $ 35,231 $ 26,416
Schedule of Other Long-Term Liabilities	Other long-term liabilities consist of the following (in thousands): December 31, 2020 2019 Litigation settlement obligation - long-term portion $ 7,634 $ 10,712 Line of credit exit fee — 600 Tax liabilities 373 373 Royalties 1,678 — Other 1,668 266 Other long-term liabilities $ 11,353 $ 11,951

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Long-Term Debt	Long-term debt consists of the following (in thousands): December 31, 2020 2019 Squadron Medical Term Loan $ 45,000 $ 45,000 Amended Credit Facility with MidCap — 12,785 Inventory Financing 3,821 2,987 Note payable for software agreements, insurance premiums and PP&E 1,887 457 PPP Loan 4,271 — Total 54,979 61,229 Add: capital leases 69 101 Less: debt discount (12,814 ) (7,393 ) Total 42,234 53,937 Less: current portion of long-term debt (4,200 ) (489 ) Total long-term debt, net of current portion $ 38,034 $ 53,448
Principal Payments on Debt	Principal payments on debt are as follows as of December 31, 2020 (in thousands): Year Ending December 31, 2021 $ 4,167 2022 1,949 2023 4,845 2024 12,018 2025 and thereafter 32,000 Total 54,979 Add: capital lease principal payments 69 Less: debt discount (12,814 ) Total 42,234 Less: current portion of long-term debt (4,200 ) Long-term debt, net of current portion $ 38,034

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Future minimum annual lease payments	Future minimum annual undiscounted lease payments under the Company’s operating and capital leases are as follows (in thousands): Year ending December 31, 2021 $ 918 2022 40 Total undiscounted lease payments 958 Less: present value adjustment (32 ) Operating lease liability 926 Less: current portion of operating lease liability (885 ) Operating lease liability, less current portion $ 41

Orthotec Settlement (Tables)

Orthotec Settlement (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Schedule of Reconciliation of Total Net Settlement Obligation	A reconciliation of the total net settlement obligation is as follows (in thousands): December 31, 2020 December 31, 2019 Litigation settlement obligation - short-term portion $ 4,000 $ 4,400 Litigation settlement obligation - long-term portion 7,634 10,712 Total 11,634 15,112 Future Interest 1,199 2,121 Total settlement obligation, gross 12,833 17,233 Related party receivable - included in stockholders' equity (4,000 ) (5,000 ) Total settlement obligation, net $ 8,833 $ 12,233

Equity (Tables)

Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Summary of Outstanding Warrants	A summary of all outstanding warrants is as follows (in thousands): Number of Warrants Strike Price Expiration 2017 PIPE Warrants 3,107 $ 2.00 June 2022 2018 PIPE Warrants 11,380 $ 3.50 May 2023 SafeOp Surgical Merger Warrants 2,165 $ 3.50 May 2023 2018 Squadron Medical Warrants 845 $ 3.15 May 2027 2019 Squadron Medical Warrants 4,839 $ 2.17 May 2027 2020 Squadron Medical Warrants 1,076 $ 4.88 May 2027 Executive Warrants 1,327 $ 5.00 December 2022 Other* 142 $ 3.85 Various through May 2023 Total 24,881 *Represents weighted average strike price

Stock Benefit Plans and Stock_2

Stock Benefit Plans and Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	A summary of the Company’s stock option activity under the Plans and related information is as follows (in thousands, except as indicated and per share data): Shares Weighted average exercise price Weighted average remaining contractual term (in years) Aggregate intrinsic value Outstanding at December 31, 2019 4,215 $ 3.27 Granted 71 $ 6.64 Exercised (241 ) $ 2.33 $ 2,253 Forfeited (94 ) $ 10.44 Outstanding at December 31, 2020 3,951 $ 3.21 6.93 $ 45,320 Options vested and exercisable at December 31, 2020 2,837 $ 3.26 6.70 $ 32,570 Options vested and expected to vest at December 31, 2020 3,951 $ 3.21 6.93 $ 45,320
Summary of Information about Restricted Stock Awards, Restricted Stock Units and Performance-Based Restricted Units Activity	The following table summarizes information about the restricted stock awards, restricted stock units and performance-based restricted units activity (in thousands, except as indicated and per share data): Shares Weighted average grant date fair value Weighted average remaining recognition period (in years) Unvested at December 31, 2019 6,727 $ 2.17 Awarded 3,964 $ 4.87 Vested (2,363 ) $ 3.52 Forfeited (112 ) $ 4.13 Unvested at December 31, 2020 8,216 $ 3.13 1.99
Schedule of Assumptions used to Estimate Fair Value of Stock Options Granted and Stock Purchase Rights under ESPP	The Company estimates the fair value of shares issued to employees under the ESPP using the Black-Scholes option-pricing model Year Ended December 31, 2020 2019 Risk-free interest rate 0.12% - 1.58% 1.58% - 2.50% Expected dividend yield — — Expected term (years) 0.50 0.50 Volatility 54.96%-102.50% 49.78%-82.08%
Summary of Common Stock Reserved for Future Issuance	Common stock reserved for future issuance consists of the following (in thousands): December 31, 2020 Warrants outstanding 24,881 Authorized for future grant under the Plans 5,015 Authorized for future grant under the Management Objective Strategic Incentive Plan 345 Authorized for future grant under the Distributor and Development Services plans 7,780 Stock options outstanding 3,951 Unvested restricted stock awards 8,216 Employee stock purchase plan 216 Series A convertible preferred stock 29 50,433

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Components of Pretax Income (Loss)	The components of the pretax income (loss) are presented in the following table (in thousands): Year Ended December 31, 2020 2019 U.S. Domestic $ (78,849 ) $ (57,141 ) Foreign — (100 ) Pretax loss from operations $ (78,849 ) $ (57,241 )
Components of Provision (Benefit) for Income Taxes from Continuing Operations	The components of the provision (benefit) for income taxes from continuing operations are presented in the following table (in thousands): Year Ended December 31, 2020 2019 Current income tax provision: Federal $ — $ — State 100 207 Foreign 35 — Total current 135 207 Deferred income tax (benefit) provision: Federal (2 ) (195 ) State 12 (251 ) Total deferred 10 (446 ) Total income tax provision (benefit) $ 145 $ (239 )
Schedule of Effective Income Tax Rate Reconciliation	The provision for income taxes differs from the amount of income tax determined by applying the applicable U.S. statutory federal income tax rate to pretax loss from continuing operations as a result of the following differences: December 31, 2020 2019 Federal statutory rate 21.00 % 21.00 % Adjustments for tax effects of: State taxes, net (0.11 )% 0.12 % Stock-based compensation (0.93 )% 0.26 % R&D credit expiration - % (5.96 )% Foreign taxes (0.04 )% - % Other permanent adjustments (1.70 )% (0.42 )% Foreign partnership liquidation - % 19.19 % Federal uncertain tax positions - % 3.25 % NOL expiration - % (3.01 )% Other (0.15 )% 1.16 % Valuation allowance (18.25 )% (35.09 )% Effective income tax rate (0.18 )% 0.50 %
Significant Components of Company's Deferred Tax Assets and Liabilities	Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2020 and 2019 are as follows (in thousands): December 31, 2020 2019 Deferred tax assets: Accruals and reserves $ 3,665 $ 2,730 Income tax credit carryforwards 1,582 1,591 Interest 8,193 4,095 Inventory 8,117 8,625 Legal settlement 2,875 3,789 Net operating losses 70,220 53,592 Stock-based compensation 2,464 2,256 Total deferred tax assets 97,116 76,678 Valuation allowance (87,489 ) (71,159 ) Total deferred tax assets, net of valuation allowance 9,627 5,519 Deferred tax liabilities: Property and equipment (7,094 ) (3,117 ) Goodwill and intangibles (2,483 ) (2,344 ) Total deferred tax liabilities (9,577 ) (5,461 ) Net deferred tax assets $ 50 $ 58
Summary of Changes to Unrecognized Tax Benefits	The following table summarizes the changes to unrecognized tax benefits (in thousands): Year ended December 31, 2020 2019 Unrecognized tax benefit at the beginning of the year $ 2,452 $ 4,334 Reductions as a result of lapse of applicable statute of limitations — (1,882 ) Unrecognized tax benefits at the end of the year $ 2,452 $ 2,452

The Company and Basis of Pres_2

The Company and Basis of Presentation - Additional Information (Details) $ / shares in Units, $ in Millions	Dec. 16, 2020USD ($)$ / sharesshares	Dec. 31, 2020segment	Dec. 16, 2020€ / shares
Company And Basis Of Presentation [Line Items]
Number of Reportable Segments | segment		1
Private Placement
Company And Basis Of Presentation [Line Items]
Sale of ATEC common stock shares | shares	12,421,242
Purchase price per share | $ / shares	$ 11.11
Gross proceeds for private placement	$ 138
Interest percentage on purchase price	9.00%
Tender Offer Agreement | EOS Imaging S.A.
Company And Basis Of Presentation [Line Items]
Share price | € / shares			€ 0.01
Tender offer price | (per share)	$ 2.99		2.45
Outstanding EOS shares	23.00%
Tender Offer Agreement | EOS Imaging S.A. | Maximum
Company And Basis Of Presentation [Line Items]
Purchase price	$ 116.9
Tender Offer Agreement | EOS Imaging S.A. | OCEANEs
Company And Basis Of Presentation [Line Items]
Tender offer price | (per share)	$ 8.55		€ 7.01

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	Dec. 04, 2019	Dec. 31, 2020USD ($)customer	Dec. 31, 2019USD ($)customershares	Dec. 18, 2020USD ($)	Jan. 01, 2020USD ($)	Sep. 30, 2019USD ($)	Mar. 31, 2019USD ($)
Significant Accounting Policies [Line Items]
Accounts receivable payment terms		30 days
Accounts receivable related to products and services		$ 23,527,000	$ 16,150,000
Operating lease, ROU asset		1,177,000	1,860,000				$ 2,400,000
Operating lease liability		926,000					$ 2,900,000
Removal of deferred rent						$ 600,000
Goodwill and intangible asset impairment charge		0
Impairment charges of Long-lived assets disposition		0	0
Impairment charges of Long-lived assets held for use		0	0
Sales, general and administrative		$ 129,156,000	101,714,000
ASU No. 2019-08
Significant Accounting Policies [Line Items]
Cumulative adjustment to accumulated deficit					$ 100,000
Change in accounting principle, Accounting standards update, Adopted [true false]		true
Change in accounting principle, Accounting standards update, Adoption date		Jan. 1, 2020
ASU No. 2019-12
Significant Accounting Policies [Line Items]
Change in accounting principle, Accounting standards update, Adopted [true false]		true
Change in accounting principle, Accounting standards update, Adoption date		Jan. 1, 2020
Change in accounting principle, Accounting standards update, Immaterial effect [true false]		true
Change in accounting principle, accounting standards update, early adoption [true false]		true
ASU No. 2018-15
Significant Accounting Policies [Line Items]
Change in accounting principle, Accounting standards update, Adopted [true false]		true
Change in accounting principle, Accounting standards update, Adoption date		Jan. 1, 2020
Change in accounting principle, Accounting standards update, Immaterial effect [true false]		true
ASU No. 2017-04
Significant Accounting Policies [Line Items]
Change in accounting principle, Accounting standards update, Adopted [true false]		true
Change in accounting principle, Accounting standards update, Adoption date		Jan. 1, 2020
Product Shipment
Significant Accounting Policies [Line Items]
Sales, general and administrative		$ 5,300,000	$ 4,000,000
SafeOp Surgical, Inc. | Common Stock
Significant Accounting Policies [Line Items]
Stock issued for acquisition | shares			886,843
Fair value, inputs, level 3
Significant Accounting Policies [Line Items]
Notional amount of foreign currency forward contracts				$ 117,900,000
Loss from change in fair value		900,000
Foreign currency forward contract liability		$ 900,000
Vesting period		4 years
Fair value of the cash settled award		$ 4,100,000	$ 1,700,000
New building lease
Significant Accounting Policies [Line Items]
Lease agreement commencement date	Feb. 1, 2021
Minimum
Significant Accounting Policies [Line Items]
Estimated useful lives of property and equipment		3 years
Minimum | Acquired Technology, Customer Relationships, Manufacturing Know-how, Licensed Technology, Supply Agreements and Certain Trade Names and Trademarks
Significant Accounting Policies [Line Items]
Intangible assets, amortization period		1 year
Maximum
Significant Accounting Policies [Line Items]
Estimated useful lives of property and equipment		7 years
Maximum | Acquired Technology, Customer Relationships, Manufacturing Know-how, Licensed Technology, Supply Agreements and Certain Trade Names and Trademarks
Significant Accounting Policies [Line Items]
Intangible assets, amortization period		20 years
Sales | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk, number of customers | customer		0	0
Accounts Receivable | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk, number of customers | customer		0	0

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Liabilities Measured at Fair Value on Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Liability Classified Equity Award
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities measured at fair value on a recurring basis	$ 4,108	$ 1,705
Foreign Currency Forward Contract
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities measured at fair value on a recurring basis	878
Level 2 | Foreign Currency Forward Contract
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities measured at fair value on a recurring basis	878
Level 3 | Liability Classified Equity Award
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities measured at fair value on a recurring basis	$ 4,108	$ 1,705

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Reconciliation of Liabilities (Details) - Fair value, inputs, level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	$ 266	$ 2,600
Settlement of milestone #2		(2,889)
Change in fair value measurement and milestone #2		289
Straight line recognition of liability classified equity award	371	173
Change in fair value measurement of liability classified equity award	1,031	93
Ending balance	$ 1,668	$ 266

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Summary of Weighted Average Assumptions Used to Compute Stock-Based Compensation Costs for Stock Options Granted (Details) - Options to purchase common stock	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.03%	2.00%
Weighted average expected life	6 years 29 days	6 years 1 month 2 days
Volatility	84.00%	80.76%

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Summary of Compensation Cost for Stock-Based Compensation Arrangements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 17,659	$ 10,956
Cost of Revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	512	146
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	2,114	752
Sales, General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 15,033	$ 10,058

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Computation of Basic and Diluted Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss, basic and diluted	$ (78,994)	$ (57,002)
Denominator:
Weighted average common shares outstanding	67,200	52,520
Weighted average unvested common shares subject to repurchase	(180)	(286)
Weighted average common shares outstanding - basic and diluted	67,020	52,234
Net loss per share, basic and diluted	$ (1.18)	$ (1.09)

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Weighted-Average Anti-Dilutive Securities Not Included in Diluted Net Loss Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities not included in diluted net loss per share (in shares)	37,077	37,566
Series A Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities not included in diluted net loss per share (in shares)	29	67
Options to purchase common stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities not included in diluted net loss per share (in shares)	3,951	4,215
Warrants to purchase common stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities not included in diluted net loss per share (in shares)	24,881	26,557
Unvested restricted stock awards
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities not included in diluted net loss per share (in shares)	8,216	6,727

Balance Sheet Details - Account

Balance Sheet Details - Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Accounts receivable	$ 23,887	$ 16,436
Less allowance for doubtful accounts	(360)	(286)
Accounts receivable, net	$ 23,527	$ 16,150

Balance Sheet Details - Invento

Balance Sheet Details - Inventories, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 6,064	$ 5,822
Work-in-process	1,982	1,578
Finished goods	67,892	51,669
Inventory, gross, total	75,938	59,069
Less reserve for excess and obsolete	(29,937)	(24,215)
Inventories, net	$ 46,001	$ 34,854

Balance Sheet Details - Propert

Balance Sheet Details - Property and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 93,316	$ 71,688
Less accumulated depreciation and amortization	(56,646)	(51,966)
Property and equipment, net	$ 36,670	19,722
Surgical instruments
Property, Plant and Equipment [Line Items]
Useful lives	4 years
Property and equipment, gross	$ 76,669	58,502
Machinery and equipment
Property, Plant and Equipment [Line Items]
Useful lives	7 years
Property and equipment, gross	$ 6,562	6,038
Computer equipment
Property, Plant and Equipment [Line Items]
Useful lives	3 years
Property and equipment, gross	$ 4,206	3,594
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Useful lives	5 years
Property and equipment, gross	$ 1,380	1,297
Leasehold improvements
Property, Plant and Equipment [Line Items]
Various useful lives of leasehold improvements	various
Property and equipment, gross	$ 1,761	1,761
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,738	$ 496

Balance Sheet Details - Additio

Balance Sheet Details - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Depreciation	$ 9.2	$ 6.8
Amortization of intangible assets	1.8	0.7
Machinery and equipment
Property, Plant and Equipment [Line Items]
Capital leased assets, gross	$ 0.1	$ 0.1

Balance Sheet Details - Intangi

Balance Sheet Details - Intangible Assets, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite Lived Intangible Assets [Line Items]
Gross Amount	$ 54,467	$ 54,593
Accumulated Amortization	(29,747)	(28,988)
Intangible Assets, net	$ 24,720	$ 25,605
Developed product technology
Finite Lived Intangible Assets [Line Items]
Useful lives	12 years	12 years
Gross Amount	$ 35,376	$ 35,376
Accumulated Amortization	(23,056)	(22,206)
Intangible Assets, net	$ 12,320	13,170
Intellectual property
Finite Lived Intangible Assets [Line Items]
Gross Amount		1,004
Accumulated Amortization		$ (1,004)
License agreements
Finite Lived Intangible Assets [Line Items]
Useful lives	1 year	1 year
Gross Amount	$ 5,536	$ 5,536
Accumulated Amortization	(965)	(740)
Intangible Assets, net	4,571	$ 4,796
Trademarks and trade names
Finite Lived Intangible Assets [Line Items]
Useful lives		0 years
Gross Amount	792	$ 792
Accumulated Amortization	(119)	(119)
Intangible Assets, net	$ 673	$ 673
Customer-related
Finite Lived Intangible Assets [Line Items]
Useful lives	3 years	4 years
Gross Amount	$ 7,458	$ 7,458
Accumulated Amortization	(3,968)	(3,481)
Intangible Assets, net	$ 3,490	$ 3,977
Distribution network
Finite Lived Intangible Assets [Line Items]
Useful lives	2 years	3 years
Gross Amount	$ 4,027	$ 4,027
Accumulated Amortization	(1,639)	(1,438)
Intangible Assets, net	$ 2,388	$ 2,589
In process research and development
Finite Lived Intangible Assets [Line Items]
Useful lives	7 years	7 years
Gross Amount	$ 1,278	$ 400
Intangible Assets, net	$ 1,278	$ 400

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule of Intangible Assets, Future Expected Amortization Expense (Details) $ in Thousands	Dec. 31, 2020USD ($)
Balance Sheet Related Disclosures [Abstract]
2021	$ 2,014
2022	2,014
2023	2,014
2024	1,911
2025	1,326
Thereafter	15,441
Total	$ 24,720

Balance Sheet Details - Accrued

Balance Sheet Details - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Commissions and sales milestones	$ 6,734	$ 5,299
Payroll and payroll related	12,247	7,949
Litigation settlement obligation - short-term portion	4,000	4,400
Professional fees	3,551	3,945
Royalties	2,293	1,981
Interest	619	155
Other	5,787	2,687
Total accrued expenses	$ 35,231	$ 26,416

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Litigation settlement obligation - long-term portion	$ 7,634	$ 10,712
Line of credit exit fee		600
Tax liabilities	373	373
Royalties	1,678
Other	1,668	266
Other long-term liabilities	$ 11,353	$ 11,951

Discontinued Operations - Addit

Discontinued Operations - Additional Information (Details) $ in Thousands	Sep. 01, 2016option	Jun. 30, 2020	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contracts revenue			$ 144,861	$ 113,427
Cost of revenues			42,360	35,833
Supply agreement
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contracts revenue			3,800	5,200
Cost of revenues			$ 3,500	$ 4,800
Discontinued operations, disposed of by sale | International Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Supply commitment term	3 years
Supply agreement, number of annual options to extend | option	2
Supply agreement, extended term		12 months
Supply agreement, extended period		2021-08

Debt - MidCap Facility Agreemen

Debt - MidCap Facility Agreement (Details) - USD ($) $ in Thousands	May 29, 2020	Dec. 31, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Final settlement under agreement	$ 9,600	$ 56,615	$ 112,934

Debt - Squadron Medical Credit

Debt - Squadron Medical Credit Agreement (Details) - USD ($)	Dec. 16, 2020	Nov. 06, 2018	Dec. 31, 2020	May 29, 2020	Dec. 31, 2019	Mar. 27, 2019
Line Of Credit Facility [Line Items]
Issuance of common stock			82,294,000		61,718,000
Number of warrants outstanding			24,881,000
Loss on debt extinguishment			$ (7,612,000)
Squadron Medical Credit Agreement
Line Of Credit Facility [Line Items]
Issuance of common stock	2,700,270
Common stock price per share	$ 11.11
Additional debt issuance costs	$ 3,800,000		12,800,000
Maximum borrowing capacity			45,000,000
Additional borrowing capacity			40,000,000
New debt issuance costs	30,000,000
Loss on debt extinguishment		$ 6,100,000
Debt instrument capitalized non-cash costs		$ 3,800,000
Debt carrying amount, net of issuance cost			32,200,000
Debt issuance costs	3,800,000		$ 12,800,000
Squadron Medical Credit Agreement | Common Stock | Participant Lender
Line Of Credit Facility [Line Items]
Number of warrants issued (in shares)		845,000				4,838,710
Exercise price of warrants		$ 3.15		$ 4.88		$ 2.17
Additional warrants issued				1,075,820
Number of warrants outstanding			6,759,530
Squadron Medical Credit Agreement | Term Loan
Line Of Credit Facility [Line Items]
Additional line of credit	$ 15,000,000
Debt instrument maturity	Jun. 30, 2026
Secured debt agreement	$ 30,000,000		$ 45,000,000		$ 45,000,000
Squadron Medical Credit Agreement | Line of Credit
Line Of Credit Facility [Line Items]
Floor on interest rate		9.00%
Ceiling on interest rate		12.00%
Payment terms			Interest-only payments are due monthly until December 2023 and joined by $1.0 million monthly principal payments beginning December 2023. Any remaining principal amounts of the Term Loan will be due on June 30, 2026.
Debt instrument, monthly principal payments		$ 1,000,000
Line of credit, unused capacity, commitment fee percentage		1.00%
Squadron Medical Credit Agreement | Line of Credit | London Interbank Offered Rate (LIBOR)
Line Of Credit Facility [Line Items]
Interest rate description		LIBOR plus 8.0
Basis spread		8.00%

Debt - Paycheck Protection Loan

Debt - Paycheck Protection Loan (Details) - Paycheck Protection Program Loans	Apr. 23, 2020USD ($)
Line Of Credit Facility [Line Items]
Proceeds from loan	$ 4,300,000
Debt instrument, maturity date	Apr. 21, 2022
Interest rate	1.00%
Debt instrument, Description	Commencing August 21, 2021, the Company is required to pay the lender equal monthly payments of principal and interest as required to fully amortize by April 21, 2022 the principal amount outstanding on the PPP Loan as of the date prescribed by guidance issued by U.S. Small Business Administration (“SBA”).
Prepayment penalties	$ 0
Amount of compensation excluded for payroll costs	$ 100,000,000
Maximum percentage forgiven for non-payroll costs.	25.00%
Maximum amount of compensation to reduce the forgiveness	$ 100,000,000

Debt - Inventory Financing Agre

Debt - Inventory Financing Agreement (Details) - Inventory Financing Agreement - USD ($)	1 Months Ended	12 Months Ended
	Nov. 30, 2018	Dec. 31, 2020	Nov. 30, 2020
Line Of Credit Facility [Line Items]
Maximum borrowing capacity	$ 3,000,000		$ 6,000,000
Line of Credit
Line Of Credit Facility [Line Items]
Debt instrument, maturity date		Nov. 6, 2023
Debt instrument, frequency of periodic payment		monthly
Obligation outstanding under inventory financing agreement		$ 3,800,000
London Interbank Offered Rate (LIBOR) | Line of Credit
Line Of Credit Facility [Line Items]
Interest rate description	LIBOR plus 8.0%
Basis spread	8.00%
Floor on interest rate	10.00%
Ceiling on interest rate	13.00%

Debt - Other Debt Agreements (D

Debt - Other Debt Agreements (Details)	12 Months Ended
	Dec. 31, 2020Agreement
Debt Disclosure [Abstract]
Capital leases interest percentage	6.40%
Number of capital lease agreement	1

Debt - Long-Term Debt (Details)

Debt - Long-Term Debt (Details) - USD ($)	Dec. 31, 2020	Dec. 16, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Inventory Financing	$ 3,821,000		$ 2,987,000
Note payable for software agreements, insurance premiums and PP&E	1,887,000		457,000
PPP Loan	4,271,000
Total	54,979,000		61,229,000
Add: capital leases	69,000		101,000
Less: debt discount	(12,814,000)		(7,393,000)
Total	42,234,000		53,937,000
Less: current portion of long-term debt	(4,200,000)		(489,000)
Total long-term debt, net of current portion	38,034,000		53,448,000
Squadron Medical Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity	45,000,000
Term Loan | Squadron Medical Credit Agreement
Debt Instrument [Line Items]
Squadron Medical Term Loan	$ 45,000,000	$ 30,000,000	45,000,000
Amended Credit Facility And Term Loan With Mid Cap
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 12,785,000

Debt - Principal Payments on De

Debt - Principal Payments on Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
2021	$ 4,167
2022	1,949
2023	4,845
2024	12,018
2025 and thereafter	32,000
Total	54,979
Add: capital lease principal payments	69	$ 101
Less: debt discount	(12,814)	(7,393)
Total	42,234	53,937
Less: current portion of long-term debt	(4,200)	(489)
Long-term debt, net of current portion	$ 38,034	$ 53,448

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	Dec. 04, 2019USD ($)ft²	Dec. 31, 2020USD ($)ft²	Dec. 31, 2019USD ($)	Jan. 01, 2019
Loss Contingencies [Line Items]
Remaining operating lease term		8 months 12 days
Rent expense		$ 1,300,000	$ 1,300,000
Cash payments related to operating lease		1,400,000	$ 1,400,000
Liability in connection with lawsuit		0
Alphatec Spine, Inc.
Loss Contingencies [Line Items]
Guaranteed obligated minimum royalty payments through 2025 and beyond		4,900,000
Third-party Provider
Loss Contingencies [Line Items]
Minimum purchase commitment requirements		$ 3,200,000
Minimum purchase commitment to be paid period		3 years
Recognized an ROU asset related to purchase agreement amount		$ 500,000
Rent expense pertaining to assets		100,000
Leased assets within purchase agreement		$ 400,000
Maximum
Loss Contingencies [Line Items]
Operating lease term		10 years
Minimum
Loss Contingencies [Line Items]
Operating lease term		1 year
Building lease
Loss Contingencies [Line Items]
Area for facility of office, engineering and research and development space | ft²	121,541	76,000
Lease agreement expiry date	Jan. 31, 2031	Jul. 31, 2021
Lease agreement commencement date	Feb. 1, 2021
Lease renewal term	260 months
Annual increase in base rent	3.00%
Operating lease discount rate				10.50%
First year | Building lease
Loss Contingencies [Line Items]
Lease rent payable per month		$ 118,000
Each year thereafter | Building lease
Loss Contingencies [Line Items]
Lease rent payable increase per month		$ 3,000
First year | Building lease
Loss Contingencies [Line Items]
Lease base rent payment per month	$ 195,000
First year | Building lease | Maximum
Loss Contingencies [Line Items]
Abatement period	10 years
First year | Building lease | Minimum
Loss Contingencies [Line Items]
Abatement period	2 years
Second year | Building lease
Loss Contingencies [Line Items]
Lease base rent payment per month	$ 244,115

Commitments and Contingencies_2

Commitments and Contingencies - Future Minimum Annual Lease Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
2021	$ 918
2022	40
Total undiscounted lease payments	958
Less: present value adjustment	(32)
Operating lease liability	926		$ 2,900
Less: current portion of operating lease liability	(885)	$ (1,314)
Operating lease liability, less current portion	$ 41	$ 925

Orthotec Settlement - Additiona

Orthotec Settlement - Additional Information (Details)	Jul. 01, 2016USD ($)	Oct. 01, 2014USD ($)	Aug. 13, 2014USD ($)installment	Oct. 31, 2020USD ($)installment	Sep. 30, 2014USD ($)	Apr. 30, 2014USD ($)	Mar. 31, 2014USD ($)	Dec. 31, 2020USD ($)installment	Dec. 31, 2019USD ($)
Loss Contingencies [Line Items]
Settlement amount to be contributed								$ 4,000,000	$ 5,000,000
Liability in connection with lawsuit								0
Orthotec LLC, litigation settlement
Loss Contingencies [Line Items]
Judgment assessed by court for (against) company			$ 49,000,000
Payments of settlement						$ 15,750,000	$ 1,750,000	$ 45,000,000
Number of quarterly installments | installment			28					5
Litigation settlement interest, quarterly installments, amount			$ 1,100,000
Litigation settlement, final installment amount			700,000
Liability in connection with lawsuit								$ 12,800,000
Orthotec LLC, litigation settlement | HealthpointCapital, LLC
Loss Contingencies [Line Items]
Judgment assessed by court for (against) company				$ 5,000,000	$ 5,000,000
Payments of settlement	$ 1,000,000							1,100,000
Number of quarterly installments | installment				5
Settlement amount to be contributed								$ 4,000,000
Beginning Fourth Quarter of 2014 | Orthotec LLC, litigation settlement
Loss Contingencies [Line Items]
Settlement amount, remaining balance		$ 31,500,000
Litigation settlement interest, quarterly installments, amount			$ 1,100,000
Litigation settlement interest rate			7.00%
Litigation settlement payments, quarterly payment amount			$ 1,100,000
Final Installment | Orthotec LLC, litigation settlement
Loss Contingencies [Line Items]
Number of quarterly installments | installment			1

Orthotec Settlement - Schedule

Orthotec Settlement - Schedule of Reconciliation of Total Net Settlement Obligation (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Litigation settlement obligation - short-term portion	$ 4,000	$ 4,400
Litigation settlement obligation - long-term portion	7,634	10,712
Total	11,634	15,112
Future Interest	1,199	2,121
Total settlement obligation, gross	12,833	17,233
Related party receivable - included in stockholders' equity	(4,000)	(5,000)
Total settlement obligation, net	$ 8,833	$ 12,233

Equity - Additional Information

Equity - Additional Information (Details) - USD ($)	Oct. 16, 2020	May 31, 2020	Dec. 31, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2017	Jun. 30, 2019	Dec. 31, 2018
Subsidiary Sale Of Stock [Line Items]
Shares issued of underwriters option to purchase additional shares				241,000
Net proceeds from offering				$ 3,341,000	$ 1,977,000
Redeemable preferred stock carrying value				$ 23,603,000	$ 23,603,000
Redeemable preferred stock authorized				20,000,000	20,000,000
Redeemable preferred stock, price per share				$ 0.0001	$ 0.0001
Number of warrants outstanding				24,881,000
Stock-based compensation				$ 17,659,000	$ 10,956,000
Patrick S. Miles
Subsidiary Sale Of Stock [Line Items]
Warrant expiration period			5 years
Number of warrants issued (in shares)			1,327,434			1,327,434
Exercise price of warrants			$ 5			$ 5
Stock-based compensation						$ 1,400,000
SafeOp Surgical, Inc.
Subsidiary Sale Of Stock [Line Items]
Warrant expiration period				5 years
Proceeds from exercise of warrant				$ 0
Number of warrants exercised				34,807	0
Number of warrants outstanding				2,164,875
Number of warrants issued (in shares)				2,200,000
Exercise price of warrants				$ 3.50
Squadron Medical | Participant Lender
Subsidiary Sale Of Stock [Line Items]
Warrant expiration period		7 years
Number of warrants outstanding				6,759,530
Number of warrants issued (in shares)		1,075,820					4,838,710	845,000
Exercise price of warrants		$ 4.88					$ 2.17	$ 3.15
Warrants And Rights Outstanding Maturity Date		May 29, 2027
2017 PIPE Warrants
Subsidiary Sale Of Stock [Line Items]
Warrant expiration period				5 years
Proceeds from exercise of warrant				$ 600,000	$ 1,100,000
Number of warrants exercised				273,554	543,864
Number of warrants outstanding				3,107,000
Exercise price of warrants				$ 2
2018 Common Stock Warrants
Subsidiary Sale Of Stock [Line Items]
Warrant expiration period				5 years
Proceeds from exercise of warrant				$ 1,300,000	$ 600,000
Number of warrants exercised				2,342,986	274,180
Number of warrants outstanding				11,379,685
Exercise price of warrants				$ 3.50
Redeemable Preferred Stock
Subsidiary Sale Of Stock [Line Items]
Redeemable preferred stock carrying value				$ 23,600,000	$ 23,600,000
Redeemable preferred stock authorized				20,000,000	20,000,000
Redeemable preferred stock redemption, price per share				$ 9	$ 9
Redeemable preferred stock, price per share				$ 7.11	$ 7.11
Common Stock
Subsidiary Sale Of Stock [Line Items]
Common stock issued				13,143,000	12,535,000
Common Stock | 2020 Offering
Subsidiary Sale Of Stock [Line Items]
Common stock issued	13,142,855
Shares issued price per share	$ 8.75
Shares issued of underwriters option to purchase additional shares	1,714,285
Net proceeds from offering	$ 107,700,000

Equity - Summary of Outstanding

Equity - Summary of Outstanding Warrants (Details)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Class Of Warrant Or Right [Line Items]
Number of Warrants	24,881,000
2017 PIPE Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	3,107,000
Strike Price | $ / shares	$ 2
Expiration	June 2022
2018 PIPE Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	11,379,685
Strike Price | $ / shares	$ 3.50
Expiration	May 2023
SafeOp Surgical Merger Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	2,165,000
Strike Price | $ / shares	$ 3.50
Expiration	May 2023
2018 Squadron Medical Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	845,000
Strike Price | $ / shares	$ 3.15
Expiration	May 2027
2019 Squadron Medical Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	4,839,000
Strike Price | $ / shares	$ 2.17
Expiration	May 2027
2020 Squadron Medical Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	1,076,000
Strike Price | $ / shares	$ 4.88
Expiration	May 2027
Executive Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	1,327,000
Strike Price | $ / shares	$ 5
Expiration	December 2022
Other Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	142,000
Strike Price | $ / shares	$ 3.85
Expiration	Various through May 2023

Stock Benefit Plans and Stock_3

Stock Benefit Plans and Stock-Based Compensation - Additional Information (Details) - USD ($)	Apr. 05, 2020	May 31, 2017	Jul. 31, 2019	Sep. 30, 2016	Dec. 31, 2020	Dec. 31, 2019	Jun. 17, 2020	Apr. 08, 2020	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance					50,433,000
Stock compensation charge					$ 900,000
Stock-based compensation					$ 17,659,000	$ 10,956,000
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued					13,143,000	12,535,000
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance					3,951,000
Weighted-average grant-date fair value of stock options granted					$ 4.71	$ 1.92
Share price					$ 14.52
Unrecognized compensation expense for stock options and awards expected to be recognized					$ 2,200,000
Straight-line basis over a weighted average period					1 year 6 months 25 days
Unvested Restricted Stock Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance					8,216,000
Restricted shares granted under the plan					3,964,000
Straight-line basis over a weighted average period					1 year 11 months 26 days
Weighted average fair value of awards granted					$ 4.87	$ 1.92
Unrecognized compensation expense for restricted stock and awards expected to be recognized					$ 22,100,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance					216,131
Stock-based compensation					$ 1,000,000	$ 700,000
Employee stock purchase plan, maximum annual compensation percentage		20.00%
Employee stock purchase plan, maximum annual compensation amount		$ 21,250
Purchase price equal to the lower of the fair market value per share (at closing) of Company common stock		85.00%
Employee stock purchase plan, offering period		6 months
Shares of common stock purchased under the ESPP					379,166	359,689
2016 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance				1,083,333
Number of shares available for grant					4,161,838		7,000,000
2016 Equity Incentive Plan | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period				10 years
Award vesting period				4 years
Exercise price minimum percentage of market price on grant date				100.00%
2016 Equity Incentive Plan | Employee Stock Option | 10 Percent Stockholder
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period				5 years
Exercise price minimum percentage of market price on grant date				110.00%
Salary-to-Equity Conversion Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting date	Jul. 10, 2020
Deferred compensation liability					$ 900,000
Salary-to-Equity Conversion Program | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Eligible employee payroll cost for conversion program	$ 100,000
Employee voluntary election to reduce compensation rate	10.00%
Salary-to-Equity Conversion Program | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee voluntary election to reduce compensation rate	75.00%
Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance					692,392
Maximum award to be deductible other than options					$ 1,000,000
2019 Management Objective Strategic Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation					$ 200,000
2019 Management Objective Strategic Incentive Plan | Board of Directors Chairman | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share authorized grant of warrants			500,000
Maximum grant of shares per participant			50,000
2019 Management Objective Strategic Incentive Plan | Unvested Restricted Stock Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum grant of shares per participant					25,000
Restricted shares granted under the plan					130,000
2017 Distributor Inducement Plan | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation					$ 500,000	$ 400,000
Common stock issued					220,000
Number of warrants available to be granted					525,000
2017 Distributor Inducement Plan | Board of Directors Chairman | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share authorized grant of warrants									1,000,000
2017 Distributor Inducement Plan | Restricted Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted under the plan					284,500
Two Thousand Seventeen Development Services Plan | Board of Directors Chairman | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant								7,000,000
Common stock issued					0
Two Thousand Seventeen Development Services Plan | Restricted Common Stock | Board of Directors Chairman
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant					5,769,000
Restricted shares granted under the plan					3,190,000

Stock Benefit Plans and Stock_4

Stock Benefit Plans and Stock-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Outstanding, Beginning balance | shares	4,215
Shares, Granted | shares	71
Shares, Exercised | shares	(241)
Shares, Forfeited | shares	(94)
Shares Outstanding, Ending balance | shares	3,951
Shares, Options vested and exercisable | shares	2,837
Shares, Options vested and expected to vest | shares	3,951
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price, Outstanding, Beginning balance | $ / shares	$ 3.27
Weighted average exercise price, Granted | $ / shares	6.64
Weighted average exercise price,Exercised | $ / shares	2.33
Weighted average exercise price, Forfeited | $ / shares	10.44
Weighted average exercise price, Outstanding, Ending balance | $ / shares	3.21
Weighted average exercise price, Options vested and exercisable | $ / shares	3.26
Weighted average exercise price, Options vested and expected to vest | $ / shares	$ 3.21
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term, Outstanding, balance	6 years 11 months 4 days
Weighted average remaining contractual term, Options vested and exercisable	6 years 8 months 12 days
Weighted average remaining contractual term, Options vested and expected to vest	6 years 11 months 4 days
Aggregate intrinsic value, Outstanding, Beginning balance | $	$ 0
Aggregate intrinsic value, Exercised | $	2,253
Aggregate intrinsic value, Outstanding, Ending balance | $	45,320
Aggregate intrinsic value, Options vested and exercisable | $	32,570
Aggregate intrinsic value, Options vested and expected to vest | $	$ 45,320

Stock Benefit Plans and Stock_5

Stock Benefit Plans and Stock-Based Compensation - Summary of Information about Restricted Stock Awards, Restricted Stock Units and Performance-Based Restricted Units Activity (Details) - Unvested restricted stock awards - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares, Unvested beginning balance	6,727
Shares, Awarded	3,964
Shares, Vested	(2,363)
Shares, Forfeited	(112)
Shares, Unvested ending balance	8,216	6,727
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted average grant date fair value, Unvested beginning balance	$ 2.17
Weighted average grant date fair value, Awarded	4.87	$ 1.92
Weighted average grant date fair value, Vested	3.52
Weighted average grant date fair value, Forfeited	4.13
Weighted average grant date fair value, Unvested ending balance	$ 3.13	$ 2.17
Weighted average remaining recognition period (in years)	1 year 11 months 26 days

Stock Benefit Plans and Stock_6

Stock Benefit Plans and Stock-Based Compensation - Schedule of Assumptions used to Estimate Fair Value of Stock Options Granted and Stock Purchase Rights under ESPP (Details) - ESPP	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate, minimum	0.12%	1.58%
Risk-free interest rate, maximum	1.58%	2.50%
Weighted average expected life	6 months	6 months
Volatility, minimum	54.96%	54.96%
Volatility, maximum	102.50%	82.08%

Stock Benefit Plans and Stock_7

Stock Benefit Plans and Stock-Based Compensation - Summary Common Stock Reserved for Future Issuance (Details) shares in Thousands	Dec. 31, 2020shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance	50,433
Warrants Outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance	24,881
Authorized for Future Grant Under the Distributor and Development Services Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance	7,780
Authorized for Future Grant Under the Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance	5,015
Authorized for Future Grant Under the Management Objective Strategic Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance	345
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance	3,951
Unvested Restricted Stock Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance	8,216
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance	216
Series A Convertible Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance	29

Income Taxes - Components of Pr

Income Taxes - Components of Pretax Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
U.S. Domestic	$ (78,849)	$ (57,141)
Foreign		(100)
Pretax loss from operations	$ (78,849)	$ (57,241)

Income Taxes - Components of _2

Income Taxes - Components of Provision (Benefit) for Income Taxes from Continuing Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Current income tax provision:
State	$ 100	$ 207
Foreign	35
Total current	135	207
Deferred income tax (benefit) provision:
Federal	(2)	(195)
State	12	(251)
Total deferred	10	(446)
Total income tax provision (benefit)	$ 145	$ (239)

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal statutory rate	21.00%	21.00%
Adjustments for tax effects of:
State taxes, net	(0.11%)	0.12%
Stock-based compensation	(0.93%)	0.26%
R&D credit expiration		(5.96%)
Foreign taxes	(0.04%)
Other permanent adjustments	(1.70%)	(0.42%)
Foreign partnership liquidation		19.19%
Federal uncertain tax positions		3.25%
NOL expiration		(3.01%)
Other	(0.15%)	1.16%
Valuation allowance	(18.25%)	(35.09%)
Effective income tax rate	(0.18%)	0.50%

Income Taxes - Significant Comp

Income Taxes - Significant Components of Company's Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Accruals and reserves	$ 3,665	$ 2,730
Income tax credit carryforwards	1,582	1,591
Interest	8,193	4,095
Inventory	8,117	8,625
Legal settlement	2,875	3,789
Net operating losses	70,220	53,592
Stock-based compensation	2,464	2,256
Total deferred tax assets	97,116	76,678
Valuation allowance	(87,489)	(71,159)
Total deferred tax assets, net of valuation allowance	9,627	5,519
Deferred tax liabilities:
Property and equipment	(7,094)	(3,117)
Goodwill and intangibles	(2,483)	(2,344)
Total deferred tax liabilities	(9,577)	(5,461)
Net deferred tax assets	$ 50	$ 58

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2018	Dec. 31, 2019
Income Tax [Line Items]
Deferred tax asset, valuation allowance	$ 87,489,000		$ 71,159,000
Number of years cumulative pre-tax loss	3 years
Indefinite life assets	$ 0
Unrecognized tax benefits	2,452,000	$ 4,334,000	$ 2,452,000
Accrued interest and penalties	0
Operating loss carryforwards state	193,400,000
Operating loss carryforwards federal	273,700,000
Federal and state net operating loss carryforwards, expiring year		2040
State research and development tax credit carryforwards	$ 3,200,000
Cumulative change in ownership percentage	50.00%
Period for cumulative change in ownership	3 years
Federal
Income Tax [Line Items]
Deferred tax asset, valuation allowance increase (decrease)	$ 14,400,000
State
Income Tax [Line Items]
Deferred tax asset, valuation allowance increase (decrease)	$ 1,900,000

Income Taxes - Summary of Chang

Income Taxes - Summary of Changes to Unrecognized Tax Benefits (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefit at the beginning of the year	$ 4,334
Reductions as a result of lapse of applicable statute of limitations	(1,882)
Unrecognized tax benefits at the end of the year	$ 2,452

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) $ in Thousands	Jul. 01, 2016USD ($)	Aug. 13, 2014USD ($)installment	Oct. 31, 2020USD ($)installment	Sep. 30, 2014USD ($)	Apr. 30, 2014USD ($)	Mar. 31, 2014USD ($)	Dec. 31, 2020USD ($)installment	Dec. 31, 2019USD ($)
Related Party Transaction [Line Items]
Settlement amount to be contributed							$ 4,000	$ 5,000
Withholding tax receivable from officer							1,076
Restricted Stock Unit
Related Party Transaction [Line Items]
Withholding tax receivable from officer							1,100
Orthotec LLC, litigation settlement
Related Party Transaction [Line Items]
Payments of settlement					$ 15,750	$ 1,750	$ 45,000
Judgment assessed by court for (against) company		$ (49,000)
Number of quarterly installments | installment		28					5
Orthotec LLC, litigation settlement | Forbearance Agreement, Settlement Payment
Related Party Transaction [Line Items]
Payments of settlement	$ 1,000						$ 1,100
Judgment assessed by court for (against) company			$ (5,000)	$ (5,000)
Number of quarterly installments | installment			5
Settlement amount to be contributed							$ 4,000

Retirement Plan - Additional In

Retirement Plan - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Contribution Plan Disclosure [Line Items]
Matching contributions by employer	4.00%
Employer matching contribution, vesting period	1 year
Section 401(k) plan
Defined Contribution Plan Disclosure [Line Items]
Total contributions	$ 0.9	$ 0.6

Subsequent Event - Additional I

Subsequent Event - Additional Information (Details) $ / shares in Units, $ in Thousands	Mar. 05, 2021USD ($)TradingDay$ / shares	Dec. 16, 2020USD ($)$ / shares	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Mar. 05, 2021€ / shares	Dec. 16, 2020€ / shares
Subsequent Event [Line Items]
Issuance of common stock for public offering, net of offering costs			$ 107,698	$ 53,848
Private Placement
Subsequent Event [Line Items]
Purchase price per share | $ / shares		$ 11.11
Gross proceeds for private placement		$ 138,000
Subsequent Event | Private Placement
Subsequent Event [Line Items]
Issuance of common stock for public offering, net of offering costs	$ 138,000
Purchase price per share | $ / shares	$ 11.11
Gross proceeds for private placement	$ 132,000
Tender Offer Agreement | EOS Imaging S.A.
Subsequent Event [Line Items]
Tender offer price | (per share)		$ 2.99				€ 2.45
Tender Offer Agreement | EOS Imaging S.A. | OCEANEs
Subsequent Event [Line Items]
Tender offer price | (per share)		$ 8.55				€ 7.01
Tender Offer Agreement | Subsequent Event | EOS Imaging S.A.
Subsequent Event [Line Items]
Tender offer price | (per share)	$ 2.99				€ 2.45
Initial tender acceptance trading days | TradingDay	25
Subsequent tender acceptance trading days | TradingDay	10
Ownership percentage on share capital and voting rights	90.00%				90.00%
Tender Offer Agreement | Subsequent Event | EOS Imaging S.A. | Maximum
Subsequent Event [Line Items]
Purchase price	$ 116,900
Tender Offer Agreement | Subsequent Event | EOS Imaging S.A. | OCEANEs
Subsequent Event [Line Items]
Tender offer price | (per share)	$ 8.55				€ 7.01