Alphatec (ATEC) 10-Q 11 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 01, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	Alphatec Holdings, Inc.
Entity Central Index Key	1,350,653
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Document Type	10-Q
Trading Symbol	ATEC
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		27,185,355

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash	$ 47,645	$ 22,466
Accounts receivable, net	11,960	14,822
Inventories, net	28,872	27,292
Prepaid expenses and other current assets	1,986	1,767
Current assets of discontinued operations	269	131
Total current assets	90,732	66,478
Property and equipment, net	11,549	12,670
Goodwill	14,346
Intangibles, net	26,514	5,248
Other assets	137	208
Noncurrent assets of discontinued operations	58	56
Total assets	143,336	84,660
Current liabilities:
Accounts payable	3,769	3,878
Accrued expenses	23,368	22,246
Current portion of long-term debt	6,891	3,306
Current liabilities of discontinued operations	467	312
Total current liabilities	34,495	29,742
Long-term debt, less current portion	34,665	37,767
Other long-term liabilities	19,000	20,206
Redeemable preferred stock, $0.0001 par value; 20,000 shares authorized at March 31, 2018 and December 31, 2017; 3,319 shares issued and outstanding at both March 31, 2018 and December 31, 2017	23,603	23,603
Commitments and contingencies
Stockholders' equity (deficit):
Common stock, $0.0001 par value; 200,000 authorized at March 31, 2018 and December 31, 2017; 25,549 and 19,857 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively	2	2
Treasury stock, at cost, 2 shares, at both March 31, 2018 and December 31, 2017	(97)	(97)
Additional paid-in capital	496,972	436,803
Shareholder note receivable	(5,000)	(5,000)
Accumulated other comprehensive income	1,071	1,093
Accumulated deficit	(461,375)	(459,459)
Total stockholders’ equity (deficit)	31,573	(26,658)
Total liabilities and stockholders’ equity (deficit)	143,336	84,660
Series A Convertible Preferred Stock
Stockholders' equity (deficit):
Convertible preferred stock
Series B Convertible Preferred Stock
Stockholders' equity (deficit):
Convertible preferred stock

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
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	25,549,000	19,857,000
Common stock, shares outstanding	25,549,000	19,857,000
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
Convertible preferred stock, shares issued	4,000
Convertible preferred stock, shares outstanding	4,000
Series B Convertible Preferred Stock
Convertible preferred stock, par value (dollars per share)	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	45,000	0
Convertible preferred stock, shares issued	45,000
Convertible preferred stock, shares outstanding	45,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Revenues	$ 21,307	$ 27,978
Cost of revenues	7,737	11,199
Gross profit	13,570	16,779
Operating expenses:
Research and development	1,786	1,449
Sales and marketing	10,060	11,103
General and administrative	6,442	6,223
Amortization of intangible assets	177	172
Transaction-related expenses	1,542
Gain on settlement	(6,168)
Restructuring expenses	398	1,231
Total operating expenses	14,237	20,178
Operating loss	(667)	(3,399)
Other income (expense):
Interest expense, net	(1,707)	(1,981)
Other income (expense), net	62	5
Total other income (expense)	(1,645)	(1,976)
Loss from continuing operations before taxes	(2,312)	(5,375)
Income tax (benefit) provision	(458)	49
Loss from continuing operations	(1,854)	(5,424)
Loss from discontinued operations, net of applicable taxes	(62)	(91)
Net loss	$ (1,916)	$ (5,515)
Net loss per share, basic and diluted:
Continuing operations	$ (0.09)	$ (0.60)
Discontinued operations	0	(0.01)
Net loss per share, basic and diluted	$ (0.09)	$ (0.61)
Shares used in calculating basic and diluted net loss per share	21,212	9,005

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (1,916)	$ (5,515)
Foreign currency translation adjustments related to continuing operations	(22)	190
Foreign currency translation adjustments related to discontinued operations	0	0
Comprehensive loss	$ (1,938)	$ (5,325)

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net loss	$ (1,916)	$ (5,515)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	1,886	1,868
Stock-based compensation	619	808
Amortization of debt discount and debt issuance costs	589	717
Provision for doubtful accounts	55	12
Provision for excess and obsolete inventory	1,345	306
Deferred income tax expense	31
Gain on settlement	(6,168)
Loss on disposal of instruments	(131)
Other non-cash items		994
Changes in operating assets and liabilities:
Accounts receivable, net	2,846	4,356
Inventories, net	(2,733)	(254)
Prepaid expenses and other current assets	(217)	1,958
Other assets	37	291
Accounts payable	(192)	(5,725)
Accrued expenses and other	(258)	(5,867)
Other long-term liabilities	(1,071)
Deferred revenues	(22)
Net cash used in operating activities	(5,300)	(6,051)
Investing activities:
Purchases of property and equipment	(410)	(1,977)
Cash paid for acquisition of SafeOp Surgical, Inc.	(13,844)
Cash received from sale of equipment	172
Net cash used in investing activities	(14,082)	(1,977)
Financing activities:
Borrowings under lines of credit	22,433	24,195
Repayments under lines of credit	(24,178)	(26,426)
Principal payments on capital lease obligations	(31)	(159)
Proceeds from sale of stock, net	47,259	17,472
Principal payments on notes payable and term loan	(900)	(1,325)
Net cash provided by financing activities	44,583	13,757
Effect of exchange rate changes on cash	(22)	96
Net increase in cash	25,179	5,825
Cash at beginning of period, including discontinued operations	22,466	19,752
Cash at end of period, including discontinued operations	47,645	25,577
Supplemental disclosure of cash flow information:
Cash paid for interest	1,092	1,277
Cash paid for income taxes	6	198
Transaction related expenses in accounts payable	542
Purchases of property and equipment in accounts payable	$ 515	$ 3,650

The Company and Basis of Presen

The Company and Basis of Presentation	3 Months Ended
	Mar. 31, 2018
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 focused on the design, development and promotion of products for the surgical treatment of spine disorders. The Company has a comprehensive product portfolio and pipeline that addresses the cervical, thoracolumbar and intervertebral regions of the spine and covers a variety of spinal disorders and surgical procedures. The Company’s principal product offerings are focused on the U.S. market for fusion-based spinal disorder solutions. On March 6, 2018, the Company and its newly-created wholly-owned subsidiary, Safari Merger Sub, Inc. (“Sub”), entered into an Agreement and Plan of Merger (the “Merger Agreement”) with SafeOp, a Delaware corporation, certain Key Stockholders of SafeOp and a Stockholder Representative. The Merger Agreement provides for a reverse triangular merger (the “Merger”), which was consummated on March 8, 2018, in which Sub was merged into SafeOp, with SafeOp being the surviving corporation and a wholly-owned subsidiary of the Company. See Note 8 for further information. On September 1, 2016, the Company completed the sale of its international distribution operations and agreements to Globus Medical Ireland, Ltd., a subsidiary of Globus Medical, Inc., and its affiliated entities (collectively “Globus”), including the Company’s wholly-owned subsidiaries in Japan, Brazil, Australia and Singapore and substantially all of the assets of the Company’s other sales operations in the United Kingdom and Italy (collectively, the “International Business”), pursuant to a purchase and sale agreement, dated as of July 25, 2016 (as amended, the “Purchase and Sale Agreement”) (the “Globus Transaction”). As a result of the Globus Transaction, the International Business has been excluded from continuing operations for all periods presented in this Quarterly Report on Form 10-Q and is reported as discontinued operations. See Note 4 for additional information on the divestiture of the International Business. The Company operates in one reportable business segment. The sale of the International Business represented a strategic shift and had a significant impact on the Company's operations and financial results. Recent Developments I n including the integration of next-generation neuromonitoring solutions, advancement of its product pipeline, and investment in sales and marketing to expand its market presence See Note 10 for further information. Basis of Presentation The accompanying condensed consolidated balance sheet as of December 31, 2017, which has been derived from audited financial statements, and the unaudited interim condensed consolidated financial statements have been prepared by the Company in accordance with U.S. generally accepted accounting principles (“GAAP”) and the rules and regulations of the Securities and Exchange Commission (“SEC”) related to a quarterly report on Form 10-Q. Certain information and note disclosures normally included in annual audited financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations, although the Company believes that the disclosures made in this Quarterly Report on Form 10-Q are adequate to make the information not misleading. The unaudited interim condensed consolidated financial statements reflect all adjustments, including normal recurring adjustments which, in the opinion of management, are necessary for a fair statement of the financial position and results of operations for the periods presented. These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements for the year ended December 31, 2017, which are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 that was filed with the SEC on March 9, 2018. Operating results for the three months ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018, or any other future periods. The Company’s annual operating plan projects that its existing working capital at March 31, 2018 of $56.2 million (including cash of $47.6 million) which includes the gross proceeds of $48.6 million received as of March 31, 2018 from the equity offering that closed on March 8, 2018 (see Note 10) as well as the amendments to its debt facilities (see Note 5), allows the Company to fund its operations through at least one year subsequent to the date the financial statements are issued. The Company has incurred significant net losses since inception and has relied on its ability to fund its operations through revenues from the sale of its products, equity financings and debt financings. As the Company has historically incurred losses, successful transition to profitability is dependent upon achieving a level of revenues adequate to support the Company’s cost structure. This may not occur and, unless and until it does, the Company will continue to need to raise additional capital. Operating losses and negative cash flows may continue for at least the next year as the Company continues to incur costs related to the execution of its operating plan and introduction of new products. As more fully described in Note 5, the Company is a party to debt agreements with MidCap Funding IV, LLC and Globus (the “Debt Agreements”). The Debt Agreements include traditional lending and reporting covenants, including a financial covenant that requires the Company to maintain a minimum fixed charge coverage ratio, beginning in April 2019. Should at any time the Company fail to maintain compliance with this covenant, the Company will need to seek waivers or amendments to the Debt Agreements. If the Company is unable to secure such waivers or amendments, it may be required to classify its obligations under the Debt Agreements in current liabilities on its consolidated balance sheet. The Company may also be required to repay all or a portion of outstanding indebtedness under the Debt Agreements, which may require the Company to obtain further financing. There is no assurance that the Company will be able to obtain further financing, or do so on reasonable terms. The accompanying condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern and do not include any adjustments that might result from the outcome of this uncertainty. A going concern basis of accounting contemplates the recovery of the Company’s assets and the satisfaction of its liabilities in the normal course of business.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The Company’s significant accounting policies are described in Note 2 to its audited consolidated financial statements for the year ended December 31, 2017, which are included in the Company’s Annual Report on Form 10-K that was filed with the SEC on March 9, 2018. Except as discussed below, these accounting policies have not significantly changed during the three months ended March 31, 2018. Revenue Recognition The Company recognizes revenue from license and collaboration agreements in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements. The Company derives its revenues primarily from the sale of spinal surgery implants 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 are 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. The Company’s accounts receivable generally have net 30 day payment terms. The Company generally does not allow returns of products that have been delivered. The Company offers standard quality assurance warranty on its products. As of March 31, 2018, accounts receivable related to products and services were $12.0 million. For the three months ended March 31, 2018, the Company had no material bad debt expense and there were no material contract assets, contract liabilities or deferred contract costs recorded on the consolidated balance sheet as of March 31, 2018. 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. As of March 31, 2018, all warrants are classified within stockholders’ equity. The Company periodically evaluates changes in facts and circumstances that could impact the classification of warrants. Transaction-related Expenses The Company expensed certain costs related to the SafeOp acquisition, which primarily include third-party advisory and legal fees . Fair Value Measurements T he carrying amount of financial instruments consisting of cash, restricted 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: The Company does not maintain any financial assets that are considered to be Level 1, Level 2 or Level 3 instruments as of March 31, 2018. The fair value of the contingent consideration liability assumed in the SafeOp acquisition is recorded as part of the purchase price consideration of the acquisition. 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. The following table provides a reconciliation of liabilities measured at fair value using significant unobservable inputs (Level 3) for the three months ended March 31, 2018 (in thousands): Level 3 Liability Balance at January 1, 2018 $ — Contingent consideration liability recorded upon acquisition of SafeOp 3,200 Change in fair value measurement — Balance at March 31, 2018 $ 3,200 The material factors that may impact the fair value of the contingent consideration, and therefore, this liability, are the probabilities of achieving the related milestones and the discount rate. Significant increases or decreases in any of the probabilities of success would result in a significantly higher or lower fair value, respectively. Any necessary Recent Accounting Pronouncements Recently Adopted Accounting Pronouncements In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) , as modified by subsequently issued ASUs 2015-14, 2016-08, 2016-10, 2016-12 and 2016-20 (collectively “ASU 2014-09”). ASU 2014-09 superseded existing revenue recognition standards with a single model unless those contracts are within the scope of other standards. The revenue recognition principle in ASU 2014-09 is that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company adopted the new standard effective January 1, 2018 using the modified retrospective approach applied to those contracts which were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under ASU 2014-09, while prior period amounts are not adjusted and continue to be reported in accordance with the historic accounting under ASC 605. The adoption of ASU 2014-09 did not have a material cumulative impact on the Company’s consolidated financial statements as of January 1, 2018. In August 2016, the FASB issued new accounting guidance, which eliminates the diversity in practice related to the classification of certain cash receipts and payments in the statement of cash flows, by adding or clarifying guidance on eight specific cash flow issues. The guidance is effective for annual and interim reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. The amendments in this update should be applied retrospectively to all periods presented, unless deemed impracticable, in which case, prospective application is permitted. The adoption did not have a material cumulative impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Clarifying the Definition of a Business In May 2017, the FASB recently issued ASU 2017-09, Compensation-Stock Compensation , to provide clarity and reduce both 1) diversity in practice and 2) cost and complexity when applying the guidance in Topic 718 to a change in the terms or conditions of a share-based payment award. ASU 2017-09 provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting under Topic 718. The amendments in ASU 2017-09 are effective for fiscal and interim reporting periods in fiscal years beginning after December 15, 2017. Early adoption is permitted, including adoption in any interim period. The amendments in ASU 2017-09 should be applied prospectively to an award modified on or after the adoption date. The adoption did not have a material cumulative impact on the Company’s consolidated financial statements. In July 2017, the FASB issued ASU 2017-11, Earnings Per Share (Topic 260); Distinguishing Liabilities from Equity (Topic 480); Derivatives and Hedging (Topic 815): (Part I) Accounting for Certain Financial Instruments with Down Round Features, (Part II) Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Non-controlling Interests with a Scope Exception. The ASU allows companies to exclude a down round feature when determining whether a financial instrument (or embedded conversion feature) is considered indexed to the entity’s own stock. As a result, financial instruments (or embedded conversion features) with down round features may no longer be required to be classified as liabilities. A company will recognize the value of a down round feature only when it is triggered and the strike price has been adjusted downward. For equity-classified freestanding financial instruments, such as warrants, an entity will treat the value of the effect of the down round, when triggered, as a dividend and a reduction of income available to common shareholders in computing basic earnings per share. For convertible instruments with embedded conversion features containing down round provisions, entities will recognize the value of the down round as a beneficial conversion discount to be amortized to earnings. The guidance in ASU 2017-11 is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted, and the guidance is to be applied using a full or modified retrospective approach. The Company early adopted the guidance in conjunction with the 2018 Private Placement. Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02 , Leases (Topic 842) In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other

Select Condensed Consolidated B

Select Condensed Consolidated Balance Sheet Details	3 Months Ended
	Mar. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Select Condensed Consolidated Balance Sheet Details	3. Select Condensed Consolidated Balance Sheet Details Accounts Receivable, net Accounts receivable, net consist of the following (in thousands): March 31, 2018 December 31, 2017 Accounts receivable $ 12,013 $ 15,328 Allowance for doubtful accounts (53 ) (506 ) Accounts receivable, net $ 11,960 $ 14,822 Inventories, net Inventories, net consist of the following (in thousands): March 31, 2018 December 31, 2017 Raw materials $ 5,961 $ 4,969 Work-in-process 791 502 Finished goods 38,854 37,933 45,606 43,404 Less reserve for excess and obsolete finished goods (16,734 ) (16,112 ) Inventories, net $ 28,872 $ 27,292 Property and Equipment, net Property and equipment, net consist of the following (in thousands except as indicated): Useful lives (in years) March 31, 2018 December 31, 2017 Surgical instruments 4 $ 52,460 $ 53,198 Machinery and equipment 7 6,012 5,503 Computer equipment 3 3,540 3,500 Office furniture and equipment 5 2,829 2,794 Leasehold improvements various 1,714 1,714 Construction in progress n/a 70 336 66,625 67,045 Less accumulated depreciation and amortization (55,076 ) (54,375 ) Property and equipment, net $ 11,549 $ 12,670 Total depreciation expense was $1.5 million and $1.6 million for the three months ended March 31, 2018 and 2017, respectively. At both March 31, 2018 and December 31, 2017, assets recorded under capital leases of $2.1 million were included in the machinery and equipment balance. Amortization of assets under capital leases is included in depreciation expense. Intangible Assets, net In conjunction with the acquisition of SafeOp during the three months ended March 31, 2018, the Company recorded a total of $21.6 million of new intangible assets. See Note 8 for further information regarding the acquisition. Intangible assets, net consist of the following (in thousands except as indicated): Remaining Avg. Useful lives (in years) March 31, 2018 December 31, 2017 Developed technology 8 $ 26,975 $ 13,876 Intellectual property — 1,004 1,004 License agreements 1 5,738 5,738 Trademarks and trade names — 792 732 Customer-related 2 7,458 7,458 Distribution network 4 4,027 4,027 In process research and development — 8,400 — 54,394 32,835 Less accumulated amortization (27,880 ) (27,587 ) Intangible assets, net $ 26,514 $ 5,248 Total amortization expense was $0.3 million and $0.2 million for the three months ended March 31, 2018 and 2017, respectively. Future amortization expense related to intangible assets as of March 31, 2018 is as follows (in thousands): Year Ending December 31, Remainder of 2018 $ 1,043 2019 1,426 2020 1,411 2021 1,411 2022 1,411 Thereafter 19,812 $ 26,514 Accrued Expenses Accrued expenses consist of the following (in thousands): March 31, 2018 December 31, 2017 Commissions and sales milestones $ 3,435 $ 3,360 Payroll and payroll related 2,653 2,968 Litigation settlements 4,400 4,400 Accrued professional fees 2,566 1,484 Royalties 1,139 1,269 Restructuring and severance accruals 539 520 Accrued taxes 286 246 Guaranteed collaboration compensation, current — 4,485 Accrued interest 377 376 Acquisition related - contingent consideration 3,200 Other 4,773 3,138 Total accrued expenses $ 23,368 $ 22,246

Discontinued Operations

Discontinued Operations	3 Months Ended
	Mar. 31, 2018
Discontinued Operations And Disposal Groups [Abstract]
Discontinued Operations	4. Discontinued Operations In connection with the Globus Transaction, 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 (the “Products”), 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. In accordance with authoritative guidance, sales to Globus are reported under continuing operations as the Company has continuing involvement under the Supply Agreement. Included in the results of continuing operations for the three months ended March 31, 2017 are revenues of $4.5 million and cost of revenue of $3.8 million from the Supply Agreement. During the three months ended March 31, 2018, the Company recorded $2.1 million in revenue and $2.0 million in cost of revenue from the Supply Agreement in continuing operations. The Company recorded $0.1 million in general and administrative expenses pertaining to discontinued operations on the Company’s condensed consolidated statements of operations and comprehensive loss for both the three months ended March 31, 2018 and 2017. In addition, on September 1, 2016, the Company entered into a five-year term credit, security and guaranty agreement with Globus (the “Globus Facility Agreement”), as further described in Note 5, pursuant to which Globus agreed to loan the Company up to $30 million, subject to the terms and conditions set forth in the Globus Facility Agreement, as amended.

Debt

Debt	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt	5. Debt MidCap Facility Agreement The Company’s Amended Credit Facility with MidCap provides for a revolving credit commitment up to $22.5 million and a term loan commitment up to $5 million. As of March 31, 2018, $8.4 million was outstanding under the revolving line of credit and $1.5 million was outstanding under the term loan. The term loan interest rate is priced at the London Interbank Offered Rate ("LIBOR") plus 8.0%, subject to a 9.5% floor, and the revolving line of credit interest rate is priced at LIBOR plus 6.0%, reset monthly. At March 31, 2018, the revolving line of credit carried an interest rate of 7.66% and the term loan carried an interest rate of 9.66%. The borrowing base is determined, from time to time, based on the value of domestic eligible accounts receivable. As collateral for the Amended Credit Facility, the Company granted MidCap first lien on accounts receivable and related assets The Amended Credit Facility also includes several event of default provisions, such as payment default, insolvency conditions and a material adverse effect clause, which could cause interest to be charged at a rate which is up to five percentage points above the rate effective immediately before the event of default or result in MidCap’s right to declare all outstanding obligations immediately due and payable. On March 8, 2018, the Company entered into a Seventh Amendment to the Amended Credit Facility to extend the date that the financial covenants of the Amended Credit Facility are effective from April 2018 to April 2019, and established a minimum liquidity covenant of $5.0 million through March 2019. The Company was in compliance with the covenants under the Amended Credit Facility at March 31, 2018. Globus Facility Agreement On September 1, 2016, the Company and Globus entered into the Globus Facility Agreement, pursuant to which Globus loaned the Company $30 million, subject to the terms and conditions set forth in the Globus Facility Agreement. As of March 31, 2018, the outstanding balance under the Globus Facility Agreement was $30.0 million, which becomes due and payable in quarterly payments of $0.8 million starting in September 2018, with a final payment of the remaining outstanding principal and interest due on September 1, 2021. The term loan interest rate is priced at LIBOR plus 8.0% through September 1, 2018, and LIBOR plus 13.0%, thereafter. At March 31, 2018, the unamortized debt discount related to the Globus Facility Agreement within the condensed consolidated balance sheet was $0.7 million, which will be amortized over the remaining term of the Globus Facility Agreement As collateral for the Globus Facility Agreement, the Company granted Globus a first lien security interest in substantially all of its assets, other than accounts receivable and related assets, which will secure the Globus Facility Agreement on a second lien basis . The Globus Facility Agreement also includes several event of default provisions, such as payment default, insolvency conditions and a material adverse effect clause, which could cause interest to be charged at a rate which is up to five percentage points above the rate effective immediately before the event of default or result in Globus’s right to declare all outstanding obligations immediately due and payable. On March 8, 2018, the Company entered into a Second Amendment to the Globus Facility Agreement to extend the date that the financial covenants of the Globus Facility Agreement are effective from April 2018 to April 2019, and established a minimum liquidity covenant of $5.0 million through March 2019. The Company was in compliance with the covenants under the Globus Facility Agreement at March 31, 2018. Principal payments on the Company's debt are as follows as of March 31, 2018 (in thousands): Year Ending December 31, Remainder of 2018 $ 6,502 2019 3,423 2020 3,380 2021 21,667 2022 and thereafter 8,424 Total 43,396 Add: capital lease principal payments 192 Less: unamortized debt discount and debt issuance costs (2,032 ) Total 41,556 Less: current portion of long-term debt (6,891 ) Long-term debt, net of current portion $ 34,665

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies Leases The Company leases certain equipment under capital leases which expire on various dates through 2018. The leases bear interest at rates ranging from 6.40% to 7.64% per annum, are generally due in monthly principal and interest installments and are collateralized by the related equipment. The Company also leases its buildings and certain equipment and vehicles under operating leases which expire on various dates through 2022. Future minimum annual lease payments under such leases are as follows as of March 31, 2018 (in thousands): Year Ending December 31, Operating Capital Remainder of 2018 $ 1,276 $ 70 2019 1,645 37 2020 1,688 37 2021 1,009 37 2022 and thereafter — 37 $ 5,618 218 Less: amount representing interest (26 ) Present value of minimum lease payments 192 Current portion of capital leases (70 ) Capital leases, less current portion $ 122 Rent expense under operating leases for the three months ended March 31, 2018 and 2017 was $0.3 million and $0.4 million, respectively. 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. On February 13, 2018, NuVasive, Inc. filed suit against the Company in the United States District Court for the Southern District of California, alleging that certain of the Company’s products (including components of the Squadron™ Lateral Retractor, the Battalion™ Lateral Spacer and other components of the 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”) (collectively, the “NuVasive Patents”). NuVasive is seeking unspecified monetary damages and a court injunction against future infringement by the Company. On March 8, 2018, the Company moved to dismiss NuVasive’s claims of infringement of its design patents on the grounds that those allegations fail to state a cognizable legal claim. On April 12, 2018, the Court took the motion under submission without oral argument. On March 26, 2018, NuVasive moved for a preliminary injunction, which, on March 27, 2018, the Court denied without prejudice for failure to comply with the Court’s chambers rules. On April 5, 2018, NuVasive again moved for a preliminary injunction. The Company’s response to that motion is due on or before May 17, 2018, and the parties currently are engaged in earing on the motion is set for June 21, 2018, at which time the Court also will conduct its initial case management conference. The Company believes that the allegations lack merit and intends to vigorously defend itself against all claims asserted and may assert its own counterclaims. In addition, the Company may also seek the following relief: (i) a declaration that the NuVasive Patents are invalid and/or that the Company does not infringe any valid claim of the NuVasive Patents; (ii) a permanent injunction against NuVasive charging that the Company has infringed or is infringing the NuVasive Patents; and (iii) costs and reasonable attorneys’ fees. in accordance with authoritative accounting guidance, 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, a competitor of the Company filed a lawsuit against Mr. Miles, the Company’s executive chairman who was a former employee of this competitor. The Company itself was not a named defendant in this lawsuit. However, the Company agreed to indemnify Mr. Miles in connection with this lawsuit, and recorded an expense of $0.1 million during the year ended December 31, 2017. As of March 31, 2018, the Company has not recorded any liability in the consolidated balance sheet related to this matter. 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 March 31, 2018, the Company is obligated to pay guaranteed minimum royalty payments under these agreements of approximately $6.1 million through 2022 and beyond.

Orthotec Settlement

Orthotec Settlement	3 Months Ended
	Mar. 31, 2018
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. In September 2014, the Company and HealthpointCapital entered into an agreement for joint payment of settlement whereby HealthpointCapital has agreed to contribute $5 million to the $49 million settlement amount. As of March 31, 2018, the Company has made installment payments in the aggregate of $32.9 million, with a remaining outstanding balance of $24.9 million (including interest). The Company has the right to prepay the amounts due without penalty. In addition, the unpaid balance of the amounts due accrues interest at the rate of 7% per year beginning May 15, 2014 until the amounts due are 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 provided 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.

Acquisition of SafeOp Surgical,

Acquisition of SafeOp Surgical, Inc.	3 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
Acquisition of SafeOp Surgical, Inc.	8. Acquisition of SafeOp Surgical, Inc. On March 9, 2018, the Company announced its acquisition of SafeOp, a privately-held provider of neuromonitoring technology designed to enable effective intra-operative nerve health assessment. SafeOp currently produces the EPAD ™ neuromonitoring device which entered the market in late 2016 (“EPAD”). SafeOp’s EPAD device is based upon somatosensory evoked potential (“SSEP”), technology and is an FDA 510(k) - cleared device designed to allow ongoing monitoring of critical nerve function. The EPAD seeks to automate SSEP’s where brain activity resulting from touch is measured, thereby eliminating the need for a technician or other neuromonitoring specialist. SafeOp is developing a product that will allow for both free run and triggered specific recording of muscle activity, also known as Electromyography (“EMG”). The Company expects to receive FDA approval for SafeOp’s EMG technology in late 2018 to complement the SSEP solution. In addition to expanding the Company’s market presence in lateral spine surgery, the Company believes that the SafeOp solution will allow it to integrate neuromonitoring into its broader product portfolio and accelerate the transition to procedural integration of the entire portfolio. The Merger was accounted for using the acquisition method of accounting. The following unaudited pro forma results of operations assume that the Company acquired Three Months Ended March 31, 2018 2017 (in thousands, except per share data) Revenue $ 21,335 $ 28,024 Loss from continuing operations (2,682 ) (6,656 ) Net loss $ (2,744 ) $ (6,747 ) Net loss per share, basic and diluted $ (0.11 ) $ (0.46 ) The unaudited pro forma information presented above is not necessarily indicative of either the results of operations that would have occurred had the acquisition of SafeOp been effective on January 1, 2018 or 2017, respectively or of the Company’s future results of operations. The results of operations for SafeOp have been included in the Company’s financial results since the acquisition date. For the three months ended March 31, 2018, the Company’s total net revenues were not materially impacted from the Merger and net loss increased by $0.2 million due to SafeOp’s operating expenses. Under the term of the definitive merger agreement, the Company agreed to pay $15.1 million in cash and agreed to issue 3,265,132 shares of common stock. On March 9, 2018 the Company paid $13.8 million in cash consideration, and expects to pay the remaining $1.3 million during the second quarter of 2018. On March 8, 2018, the Company issued 2,975,209 shares of common stock valued at $9.8 million, based on the closing share price of $3.30, and expects to issue the additional shares during the second quarter of 2018. The Company also issued $3 million in convertible notes that are convertible into a total of 987,578 shares, which includes total expected interest to be incurred, of common stock and issued warrants to purchase 2.2 million shares of common stock at an exercise price of $3.50 per share. An additional 1,330,263 shares of common stock are issuable upon achievement of post-closing milestones. The total purchase price is presented below (in thousands): Cash paid and payable $ 15,103 Common stock issued and issuable 10,756 Note 3,000 Warrants 1,650 Contingent Consideration 3,200 Total $ 33,709 The Company has measured the identifiable assets and liabilities assumed at their acquisition date fair values separately from goodwill. The intangible assets acquired includes the EPAD tradename, in-process research and development (“IPR&D”) for the EMG technology, and the developed technology for SSEP. The fair value of the EPAD tradename was determined to be $60,000 with an estimated useful life of one year. The IPR&D for the EMG technology is considered to have an indefinite life until the development is completed (i.e. once FDA clearance is obtained), at which point the Company will determine the intangible asset’s estimate useful life. The developed SSEP technology has an estimated fair value of $13.1 million with an estimated useful life of 20 years. Due to the short time frame since the acquisition date, the Company recorded the net tangible and intangible assets acquired and liabilities assumed based upon the preliminary valuation. The preliminary valuations, along with the Company’s estimates and assumptions, are subject to change within the measurement period (not to exceed one year). The primary areas of the preliminary purchase price allocation still in process relate to the fair values of assets acquired and liabilities assumed including: IPR&D, EPAD tradename and developed SSEP technology and related deferred tax consequences. The allocation of the purchase price to the assets acquired and liabilities assumed based on their fair values, is as follows (in thousands): Assets acquired: Accounts receivable $ 40 Inventory 192 Prepaid expenses and other current assets 89 Total current assets $ 321 Property and equipment, net 20 Other long-term assets 5 IPR&D 8,400 EPAD Tradename 60 Developed Technology 13,100 Total assets $ 21,906 Liabilities assumed: Accounts payable $ 54 Accrued expenses 148 Deferred tax liability 2,341 Total liabilities $ 2,543 Goodwill 14,346 Total consideration transferred $ 33,709 The purchase price exceeded the fair value of the net tangible and identifiable intangible assets acquired from SafeOp. As a result, the Company recorded goodwill in connection with the Merger. Specifically, the goodwill recorded as part of the Merger includes the assembled workforce and synergies associated with the combined entity. The goodwill is not expected to be deductible for tax purposes. As a result of the Merger, for the three months ended March 31, 2018, the Company incurred $1.5 million in total transaction costs which, in accordance with authoritative accounting guidance, were expensed as incurred. The Company agreed to issue additional shares of common stock for up to $4.3 million upon achievement of post-closing milestones (the “Contingent Consideration”). The first milestone includes payment of up to $1.4 million 10 days after submission of an application for Regulatory Approval (as that term is defined in the Merger agreement) for an indication for regulatory clearance for use of a product that includes specifically recording of muscle activity (EMG). The second milestone includes a payment of up to $2.9 million 10 days after the receipt Regulatory Approval from any Regulatory Authority (as those terms are defined in the Merger agreement) for an indication for use of a product that includes specifically EMG. The Contingent Consideration is recorded as a liability and measured at fair value 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. The material factors that may impact the fair value of the Contingent Consideration, and therefore, this liability, are the probabilities of achieving the related milestones and the discount rate. Significant increases or decreases in any of the probabilities of success would result in a significantly higher or lower fair value, respectively. The fair value of the Contingent Consideration, and the associated liability relating to the Contingent Consideration at each reporting date, will be re-assessed with the changes in fair value reflected in earnings.

Net Loss Per Share

Net Loss Per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Net Loss Per Share	9. 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 common shares outstanding for the period, without consideration for common stock equivalents. Diluted EPS is computed by dividing the net income available to common stockholders by the weighted average number of common shares 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, options, performance-based restricted stock units 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 presents the computation of basic and diluted net loss per share for continuing and discontinued operations (in thousands, except per share amounts): Three Months Ended March 31, 2018 2017 Numerator: Loss from continuing operations $ (1,854 ) $ (5,424 ) Loss from discontinued operations (62 ) (91 ) Net loss $ (1,916 ) $ (5,515 ) Denominator: Weighted average common shares outstanding 21,212 9,089 Weighted average unvested common shares subject to repurchase — (84 ) Weighted average common shares outstanding—basic and diluted 21,212 9,005 Net loss per share, basic and diluted: Continuing operations $ (0.09 ) $ (0.60 ) Discontinued operations $ (0.00 ) $ (0.01 ) Net loss per share, basic and diluted $ (0.09 ) $ (0.61 ) The anti-dilutive securities not included in diluted net Three Months Ended March 31, 2018 2017 Options to purchase common stock 316 1,164 Unvested restricted share awards — 84 Series A Convertible Preferred Stock 2,505 7,622 Series B Convertible Preferred Stock 5,045 — Convertible Notes 238 — Warrants to purchase common stock 4,874 9,440 12,978 18,310

Stock Benefit Plans and Equity

Stock Benefit Plans and Equity Transactions	3 Months Ended
	Mar. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Benefit Plans and Equity Transactions	10. Stock Benefit Plans and Equity Transactions Stock Benefit Plans 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 such new employee to begin employment with the Company. The Inducement Plan currently has 3,150,000 shares of common stock reserved for issuance. Equity awards under the Inducement Plan 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 Equity Incentive 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. Total stock-based compensation for the three months ended March 31, 2018 and 2017 is as follows (in thousands): Three Months Ended March 31, 2018 2017 Cost of revenues $ 22 $ 3 Research and development (116 ) 311 Sales and marketing 111 73 General and administrative 602 421 Total $ 619 $ 808 The negative stock-based compensation expense recorded within the Company’s research and development expense is a result of the revaluation of the Company’s Elite Medical Holdings and Pac 3 Surgical Collaboration liability of a decrease of $0.2 million. The agreement and subsequent termination are described further in Note 11. Shares Reserved For Future Issuance As of March 31, 2018, the Company had reserved shares of its common stock for future issuance as follows (in thousands): March 31, 2018 Stock options outstanding 3,180 Unvested restricted stock award 2,034 Employee stock purchase plan 411 Series A convertible preferred stock 2,022 Series B convertible preferred stock 14,349 Convertible Notes 988 Warrants outstanding 23,182 Merger shares issuable 290 Merger contingently issuable 1,330 Authorized for future grant under the Plans 439 48,225 Series A Convertible Preferred Stock On March 22, 2017, the Company entered into the Securities Purchase Agreement with certain institutional and accredited investors, including certain directors, executive officers and employees of the Company (collectively, the “Purchasers”), providing for the sale by the Company of 1,809,628 shares of the Company’s common stock at a purchase price of $2.00 per share (the “Common Shares”), 15,245 shares of newly designated Series A Convertible Preferred Stock at a purchase price of $1,000 per share (which shares are convertible into approximately 7,622,372 shares of common stock, and were initially subject to limitations on conversion prior to the approval by the Company’s stockholders (“2017 Stockholder Approval”) as required in accordance with the NASDAQ listing rules), and warrants to purchase up to 9,432,000 shares of the Company’s common stock at an exercise price of $2.00 per share (the “2017 Common Stock Warrants”), in a private placement (the “2017 Private Placement”). The 2017 Common Stock Warrants became exercisable following 2017 Stockholder Approval, are subject to certain ownership limitations, and expire five years after June 15, 2017, the date 2017 Stockholder Approval was received. The Series A Convertible Preferred Stock are entitled to dividends on an as-if-converted basis in the same form as any dividends actually paid on shares of common stock or other securities. Except as otherwise required by law, the holders of Series A Convertible Preferred Stock have no right to vote on matters submitted to a vote of the Company’s stockholders. Without the prior written consent of 75% of the outstanding shares of Series A Convertible Preferred Stock, the Company may not: (a) alter or change adversely the powers, preferences or rights given to the Series A Convertible Preferred Stock or alter or amend the Certificate of Designation, (b) amend the Company’s certificate of incorporation or other charter documents in any manner that adversely affects any rights of the holders of Series A Convertible Preferred Stock, (c) increase the number of authorized shares of Series A Convertible Preferred Stock, or (d) enter into any agreement with respect to any of the foregoing. In the event of the dissolution and winding up of the Company, the proceeds available for distribution to the Company’s stockholders shall be distributed pari passu among the holders of the shares of common stock and Series A Convertible Preferred Stock, pro rata based upon the number of shares held by each such holder, as if the outstanding shares of Series A Convertible Preferred Stock were convertible, and were converted, into shares of common stock. During the three months ended March 31, 2018, 1,274 shares of Series A Preferred Stock were converted into 636,997 shares of common stock. As of March 31, 2018, there were 4,043 shares of Series A Convertible Preferred Stock outstanding, which are convertible into 2,021,673 shares of Common Stock. In conjunction with the 2017 Private Placement, the Company also issued warrants to purchase common stock to the exclusive placement agents for the issuance (“the 2017 Banker Warrants”). The warrants were for the purchase of up to an aggregate of 471,600 shares of the Company’s common stock with substantially the same terms as the 2017 Common Stock Warrants, except that they have an exercise price equal $2.50 per share. During the three months ended March 31, 2018, 304,182 of the 2017 Banker Warrants were exercised for total cash proceeds upon exercise of $0.8 million during the quarter. A total of 167,418 of the 2017 Banker Warrants remained outstanding as of March 31, 2018. The 2017 Private Placement, including the issuance of the 2017 Banker Warrants, closed on March 29, 2017, with aggregate gross proceeds to the Company of approximately $18.9 million. 2017 Common Stock Warrants The 2017 Common Stock Warrants, are exercisable for cash. The exercise price of the 2017 Common Stock Warrants is subject to adjustment in the case of stock dividends or other distributions on shares of common stock or any other equity or equity equivalent securities payable in shares of common stock, stock splits, stock combinations, reclassifications or similar events affecting the Company’s common stock, and also, subject to limitations, upon any distribution of assets, including cash, stock or other property to the Company’s stockholders. Prior to exercise, holders of the 2017 Common Stock Warrants do not have any of the rights of holders of the common stock purchasable upon exercise, including voting rights; however, the holders of the 2017 Common Stock Warrants have certain rights to participate in distributions or dividends paid on the Company’s common stock to the extent set forth in the 2017 Common Stock Warrants. The 2017 Common Stock Warrants may not be exercised by the holder to the extent that the holder, together with its affiliates, would beneficially own, after such exercise more than 4.99% of the shares of the Company’s common stock then outstanding (subject to the right of the holder to increase or decrease such beneficial ownership limitation upon notice to us, provided that such limitation cannot exceed 9.99%) and provided that any increase in the beneficial ownership limitation shall not be effective until 61 days after such notice is delivered. If the Company effects a fundamental transaction, then upon any subsequent exercise of any 2017 Common Stock Warrants, the holder thereof shall have the right to receive, for each share of common stock that would have been issuable upon such exercise immediately prior to the occurrence of such fundamental transaction, the number of shares of the successor’s or acquiring corporation’s common stock or of the Company’s common stock, if the Company is the surviving corporation, and any additional consideration receivable as a result of such fundamental transaction by a holder of the number of shares of common stock into which the 2017 Common Stock Warrants were exercisable immediately prior to such fundamental transaction. In addition, in the event of a fundamental transaction (other than a fundamental transaction not approved by the Company’s Board of Directors), the Company or any successor entity shall, at the holder’s option, purchase the holder’s 2017 Common Stock Warrants for an amount of cash equal to the value of the 2017 Common Stock Warrants as determined in accordance with the Black Scholes option pricing model. A fundamental transaction as described in the 2017 Common Stock Warrants generally includes any merger with or into another entity, sale of all or substantially all of the Company’s assets, tender offer or exchange offer, reclassification of the Company’s common stock or the consummation of a transaction whereby another entity acquires more than 50% of the Company’s outstanding voting stock. Based on the terms of the 2017 Common Stock Warrants, the Company may be required to settle such warrants with cash upon a fundamental transaction, as defined. Through October 19, 2017, the holders of 2017 Common Stock Warrants did not control the Company’s Board of Directors, and therefore, since potential future cash settlement was deemed to be within the Company’s control, the 2017 Common Stock Warrants were classified in stockholders’ equity in accordance with the authoritative accounting guidance. Effective with the appointment of Ward W. Woods (a holder of 2017 Common Stock Warrants) to the Company’s board of directors on October 17, 2017, the holders of 2017 Common Stock Warrants now represent a majority of the Board of Directors. As a result of this change, the Company was required to re-classify the warrants as a liability in accordance with the authoritative accounting guidance. On December 29, 2017, two board members who are holders of 2017 Common Stock Warrants entered into recusal agreements, pursuant to which they agreed to abstain from voting on any fundamental transaction so long as their 2017 Common Stock Warrants are outstanding. Consequently, the 2017 Common Stock Warrants were re-classified into the equity section of the consolidated balance sheet as of December 29, 2017 and remain in equity as of March 31, 2018. In conjunction with the 2018 Private Placement described further below, a holder of 2.4 million 2017 Common Stock Warrant Holder exercised 1.7 million 2017 During the three months ended March 31, 2018, excluding the $3.4 million described above, the Company received proceeds of approximately in connection with the exercise of approximately of 2017 Common Stock Warrants. As of March 31, 2018, there were 6,007,090 2017 Common Stock Warrants outstanding. 2018 Private Placement and Series B Convertible Preferred Stock On March 8, 2018, the Company completed the 2018 Private Placement to certain institutional and accredited investors, including certain directors and executive officers of the Company, at a purchase price of $1,000 per share, 45,200 of newly designated Series B Convertible Preferred Stock, which shares of preferred stock will be converted into 12,617,857 shares (subject to adjustment as described below and in the Certificate of Designations) of the Company’s common stock upon approval by the Company’s stockholders (“2018 Stockholder Approval”), and warrants to purchase up to 12,196,851 shares of common stock at an exercise price of $3.50 per share (the “2018 Common Stock Warrants”). The 2018 Common Stock Warrants will become exercisable following 2018 Stockholder Approval, are subject to certain ownership limitations in certain cases, and expire five years after the date of such 2018 Stockholder Approval. The gross proceeds from the 2018 Private Placement were approximately $45.2 million. A total of 45,200 shares of Series B Convertible Preferred Stock are authorized for issuance under a Certificate of Designation of Preferences, Rights and Limitations of Series B Convertible Preferred Stock of the Company (the “Certificate of Designation”) filed with the Secretary of State of the State of Delaware on March 8, 2018 in connection with the closing of the 2018 Private Placement. Each share of Series B Convertible Preferred Stock has a stated value of $1,000 and is convertible into approximately 317 shares of common stock. Until the date that 2018 2018 The Series B Convertible Preferred Stock will be entitled to dividends on an as-if-converted basis in the same form as any dividends actually paid on shares of common stock or other securities. The initial conversion price of $3.15 is subject to appropriate adjustment in the event of a stock split, stock dividend, combination, reclassification or other recapitalization affecting the common stock. In addition, until the date that is one year from the effective date of the resale registration statement filed in connection with the 2018 Private Placement, the conversion price is also subject to full ratchet anti-dilution protection in the event the Company issues securities at an effective price less than the initial conversion price, subject to certain exceptions. If the Company’s stockholders do not approve the conversion of the Series B Convertible Preferred Stock, the shares of Series B Convertible Preferred Stock will not become convertible, and will remain outstanding in accordance with the terms of the Certificate of Designation. Except as otherwise required by law, the holders of Series B Convertible Preferred Stock will have no right to vote on matters submitted to a vote of the Company’s stockholders. Without the prior written consent of 75% of the outstanding shares of Series B Convertible Preferred Stock, however, the Company may not: (a) alter or change adversely the powers, preferences or rights given to the Preferred Stock or alter or amend the Certificate of Designation, (b) amend the Company’s certificate of incorporation or other charter documents in any manner that adversely affects any rights of the holders of Series B Convertible Preferred Stock, (c) increase the number of authorized shares of Series B Convertible Preferred Stock, or (d) enter into any agreement with respect to any of the foregoing. In the event of the dissolution and winding up of the Company, the proceeds available for distribution to the Company’s stockholders shall be distributed pari passu 2018 Common Stock Warrants The 2018 Common Stock Warrants, are exercisable for cash or by cashless exercise. The exercise price of the 2018 Common Stock Warrants is subject to adjustment in the case of stock dividends or other distributions on shares of common stock or any other equity or equity equivalent securities payable in shares of common stock, stock splits, stock combinations, reclassifications or similar events affecting the Company’s common stock, and also, subject to limitations, upon any distribution of assets, including cash, stock or other property to the Company’s stockholders. Prior to the exercise, holders of the 2018 Common Stock Warrants do not have any of the rights of holders of the common stock purchasable upon exercise, including voting rights; however, the holders of the 2018 Common Stock Warrants have certain rights to participate in distributions or dividends paid on the Company’s common stock to the extent set forth in the 2018 Common Stock Warrants. Some of the 2018 Common Stock Warrants may not be exercised by the holder to the extent that the holder, together with its affiliates, would beneficially own, after such exercise more than 4.99% of the shares of the Company’s common stock then outstanding (subject to the right of the holder to increase or decrease such beneficial ownership limitation upon notice to us, provided that such limitation cannot exceed 9.99%) and provided that any increase in the beneficial ownership limitation shall not be effective until 61 days after such notice is delivered. If the Company effects a fundamental transaction, then upon any subsequent exercise of any 2018 Common Stock Warrants, the holder thereof shall have the right to receive, for each share of common stock that would have been issuable upon such exercise immediately prior to the occurrence of such fundamental transaction, the number of shares of the successor’s or acquiring corporation’s common stock or of the Company’s common stock, if the Company is the surviving corporation, and any additional consideration receivable as a result of such fundamental transaction by a holder of the number of shares of common stock into which the 2018 Common Stock Warrants were exercisable immediately prior to such fundamental transaction. A fundamental transaction as described in the 2018 Common Stock Warrants generally includes any merger with or into another entity, sale of all or substantially all of the Company’s assets, tender offer or exchange offer, reclassification of the Company’s common stock or the consummation of a transaction whereby another entity acquires more than 50% of the Company’s outstanding voting stock. In addition to the 12,196,851 warrants issued in the 2018 Private Placement, the Company issued 1,275,000 warrants to an existing holder with identical terms to the 2018 Common Stock Warrants, including the exercise price of $3.50. All the 2018 Common Stock Warrants were deemed to qualify for equity classification under authoritative accounting guidance. A summary of all outstanding warrants is as follows: Number of Warrants Strike Price 2017 Common Stock Warrants 6,007,090 $ 2.00 2017 Banker Warrants 167,418 $ 2.50 2018 Common Stock Warrants 13,471,851 $ 3.50 Merger Warrants 2,200,000 $ 3.50 Executive 1,327,434 $ 5.00 Other 7,812 $ 19.20 Total 23,181,605 2017 Distributor Inducement Plan In December 2017, the Company adopted the 2017 Distributor Inducement Plan which authorizes the Company’s Chief Executive Officer to issue to distributors common stock of the Company and/or warrants to purchase the Company’s common stock. The warrants are issued with exercise price equal to the fair market value of the common stock on the date of issuance. Each warrant and common stock issuance is subject to a time-based or net sales-based vesting provision. As of March 31, 2018, 0.2 million warrants and 17,000 shares of common stock were issued under the 2017 Distributor Inducement Plan. Total expense for the plan was immaterial for the three months ended March 31, 2018. In December 2017, the Board of Directors also authorized grant of warrants to purchase 50,000 of the Company’s common stock, and 75,000 restricted stock units to a distributor. These warrants and restricted stock units are subject to time based and net sales based vesting conditions.

Termination and Settlement of E

Termination and Settlement of Elite Medical Holdings and Pac 3 Surgical Collaboration Agreement	3 Months Ended
	Mar. 31, 2018
Termination And Settlement Agreement [Abstract]
Termination and Settlement of Elite Medical Holdings and Pac 3 Surgical Collaboration Agreement	11. Termination and Settlement of Elite Medical Holdings and Pac 3 Surgical Collaboration Agreement In February 2018, the Company reached a settlement agreement with Elite Medical Holdings and Pac 3 Surgical, pursuant to which the Company made a cash payment of $0.4 million as the final and total compensation under the original agreement. In addition, the parties agreed to release each other and waive any and all rights and claims arising from the original agreement. The Company recorded a gain of approximately $6.2 million for the three months ended March 31, 2018, reflecting the reversal of accrued obligations previously recorded under the collaboration.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes To calculate its interim tax provision, at the end of each interim period the Company estimates the annual effective tax rate and applies that to its ordinary quarterly earnings. In addition, the effect of changes in enacted tax laws or rates or tax status is recognized in the interim period in which the change occurs. The computation of the annual estimated effective tax rate at each interim period requires certain estimates and significant judgment including, but not limited to, the expected operating income for the year, projections of the proportion of income earned and taxed in foreign jurisdictions, permanent and temporary differences between book and tax amounts, and the likelihood of recovering deferred tax assets generated in the current year. The accounting estimates used to compute the provision for income taxes may change as new events occur, additional information is obtained or the tax environment changes. Intraperiod tax allocation rules require the Company to allocate the provision for income taxes between continuing operations and other categories of earnings, such as discontinued operations. In periods in which the Company has a year-to-date pre-tax loss from continuing operations and pre-tax income in other categories of earnings, such as discontinued operations, the Company must allocate the tax provision to the other categories of earnings, and then record a related tax benefit in continuing operations. The unrecognized tax benefits at March 31, 2018 and December 31, 2017 were $4.4 million for both periods, with no changes occurring during the quarter. With the facts and circumstances currently available to the Company, it is reasonably possible that the amount of reserves that could reverse over the next 12 months is approximately $0.1 million. The Company recognizes interest and penalties related to uncertain tax positions as a component of the income tax provision. The Company is not currently under examination by the Internal Revenue Service, foreign, or state or local tax authorities. The income tax benefit from continuing operations for the three months ended March 31, 2018 consists primarily of a release of the valuation allowance due to an increase in net deferred tax liabilities recorded as a result of the acquisition of SafeOp. The Company’s effective tax rate of 19.8% for the three months ended March 31, 2018 differs from the federal statutory rate of 21% primarily due to the change in the valuation allowance related to the SafeOp acquisition, as noted above. The FASB issued ASU 2018-05, Income Taxes (Topic 740): "Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118" to address the application of GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Cuts and Jobs Act (the “Act”). At March 31, 2018, the Company has not completed its accounting for all of the tax effects of the Act and has not made an adjustment to the provisional tax benefit recorded under SAB 118 at December 31, 2017. The Company has estimated its provision for income taxes in accordance with the Act and guidance available as of the date of this filing. The Company’s estimated annual effective tax rate may be adjusted in subsequent interim periods, due to, among other things, additional analysis, changes in interpretations and assumptions made by the Company, and additional regulatory guidance that may be issued.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	13. Related Party Transactions For the three months ended March 31, 2018 and 2017, respectively, the Company incurred expenses of less than $0.1 million related to HealthpointCapital, LLC. As of March 31, 2018, the Company also had a liability of less than $0.1 million payable to HealthpointCapital, LLC for travel and administrative expenses. 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 million to the $49 million Orthotec settlement amount. Certain of the Company’s board of directors and senior management participated in the March 2017 and 2018 Private Placements.

Restructuring

Restructuring	3 Months Ended
	Mar. 31, 2018
Restructuring And Related Activities [Abstract]
Restructuring	14. Restructuring In connection with the Globus Transaction (described in Note 4), the Company terminated employment agreements with several executive officers, including the chief executive officer and the chief financial officer, and commenced an employee headcount reduction program. The Company had additional headcount reductions in February 2017, and recorded restructuring expenses of $0.4 million for the three months ended March 31, 2018, related to severance liability and post-employment benefits. A rollforward of the accrued restructuring liability is presented below (in thousands): Balance as of January 1, 2018 $ 520 Accrued restructuring charges 398 Payments (379 ) Balance as of March 31, 2018 $ 539 All activities and costs are expected to be completed during 2018. On July 6, 2015, the Company announced a restructuring of its manufacturing operations in California in an effort to improve its cost structure. The restructuring included a reduction in workforce and closing the California manufacturing facility. The Company incurred expenses of $1.2 million during the three months ended March 31, 2017, related to these restructuring activities. There was no expense attributed to this transaction for the three months ended March 31, 2018.

Subsequent events

Subsequent events	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent events	15. Subsequent events During the second quarter 2018, an additional 1.6 million 2017 Common Stock Warrants were exercised for total cash proceeds of $3.1 million.

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Revenue Recognition	Revenue Recognition The Company recognizes revenue from license and collaboration agreements in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements. The Company derives its revenues primarily from the sale of spinal surgery implants 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 are 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. The Company’s accounts receivable generally have net 30 day payment terms. The Company generally does not allow returns of products that have been delivered. The Company offers standard quality assurance warranty on its products. As of March 31, 2018, accounts receivable related to products and services were $12.0 million. For the three months ended March 31, 2018, the Company had no material bad debt expense and there were no material contract assets, contract liabilities or deferred contract costs recorded on the consolidated balance sheet as of March 31, 2018.
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. As of March 31, 2018, all warrants are classified within stockholders’ equity. The Company periodically evaluates changes in facts and circumstances that could impact the classification of warrants.
Transaction-related Expenses	Transaction-related Expenses The Company expensed certain costs related to the SafeOp acquisition, which primarily include third-party advisory and legal fees .
Fair Value Measurements	Fair Value Measurements T he carrying amount of financial instruments consisting of cash, restricted 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: The Company does not maintain any financial assets that are considered to be Level 1, Level 2 or Level 3 instruments as of March 31, 2018. The fair value of the contingent consideration liability assumed in the SafeOp acquisition is recorded as part of the purchase price consideration of the acquisition. 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. The following table provides a reconciliation of liabilities measured at fair value using significant unobservable inputs (Level 3) for the three months ended March 31, 2018 (in thousands): Level 3 Liability Balance at January 1, 2018 $ — Contingent consideration liability recorded upon acquisition of SafeOp 3,200 Change in fair value measurement — Balance at March 31, 2018 $ 3,200 The material factors that may impact the fair value of the contingent consideration, and therefore, this liability, are the probabilities of achieving the related milestones and the discount rate. Significant increases or decreases in any of the probabilities of success would result in a significantly higher or lower fair value, respectively. Any necessary
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently Adopted Accounting Pronouncements In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) , as modified by subsequently issued ASUs 2015-14, 2016-08, 2016-10, 2016-12 and 2016-20 (collectively “ASU 2014-09”). ASU 2014-09 superseded existing revenue recognition standards with a single model unless those contracts are within the scope of other standards. The revenue recognition principle in ASU 2014-09 is that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company adopted the new standard effective January 1, 2018 using the modified retrospective approach applied to those contracts which were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under ASU 2014-09, while prior period amounts are not adjusted and continue to be reported in accordance with the historic accounting under ASC 605. The adoption of ASU 2014-09 did not have a material cumulative impact on the Company’s consolidated financial statements as of January 1, 2018. In August 2016, the FASB issued new accounting guidance, which eliminates the diversity in practice related to the classification of certain cash receipts and payments in the statement of cash flows, by adding or clarifying guidance on eight specific cash flow issues. The guidance is effective for annual and interim reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. The amendments in this update should be applied retrospectively to all periods presented, unless deemed impracticable, in which case, prospective application is permitted. The adoption did not have a material cumulative impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Clarifying the Definition of a Business In May 2017, the FASB recently issued ASU 2017-09, Compensation-Stock Compensation , to provide clarity and reduce both 1) diversity in practice and 2) cost and complexity when applying the guidance in Topic 718 to a change in the terms or conditions of a share-based payment award. ASU 2017-09 provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting under Topic 718. The amendments in ASU 2017-09 are effective for fiscal and interim reporting periods in fiscal years beginning after December 15, 2017. Early adoption is permitted, including adoption in any interim period. The amendments in ASU 2017-09 should be applied prospectively to an award modified on or after the adoption date. The adoption did not have a material cumulative impact on the Company’s consolidated financial statements. In July 2017, the FASB issued ASU 2017-11, Earnings Per Share (Topic 260); Distinguishing Liabilities from Equity (Topic 480); Derivatives and Hedging (Topic 815): (Part I) Accounting for Certain Financial Instruments with Down Round Features, (Part II) Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Non-controlling Interests with a Scope Exception. The ASU allows companies to exclude a down round feature when determining whether a financial instrument (or embedded conversion feature) is considered indexed to the entity’s own stock. As a result, financial instruments (or embedded conversion features) with down round features may no longer be required to be classified as liabilities. A company will recognize the value of a down round feature only when it is triggered and the strike price has been adjusted downward. For equity-classified freestanding financial instruments, such as warrants, an entity will treat the value of the effect of the down round, when triggered, as a dividend and a reduction of income available to common shareholders in computing basic earnings per share. For convertible instruments with embedded conversion features containing down round provisions, entities will recognize the value of the down round as a beneficial conversion discount to be amortized to earnings. The guidance in ASU 2017-11 is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted, and the guidance is to be applied using a full or modified retrospective approach. The Company early adopted the guidance in conjunction with the 2018 Private Placement. Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02 , Leases (Topic 842) In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other

Summary of Significant Accoun23

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Reconciliation of liabilities measured at fair value using significant unobservable inputs	The following table provides a reconciliation of liabilities measured at fair value using significant unobservable inputs (Level 3) for the three months ended March 31, 2018 (in thousands): Level 3 Liability Balance at January 1, 2018 $ — Contingent consideration liability recorded upon acquisition of SafeOp 3,200 Change in fair value measurement — Balance at March 31, 2018 $ 3,200

Select Condensed Consolidated24

Select Condensed Consolidated Balance Sheet Details (Tables)	3 Months Ended
	Mar. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Accounts receivable, net	Accounts receivable, net consist of the following (in thousands): March 31, 2018 December 31, 2017 Accounts receivable $ 12,013 $ 15,328 Allowance for doubtful accounts (53 ) (506 ) Accounts receivable, net $ 11,960 $ 14,822
Inventories, net	Inventories, net consist of the following (in thousands): March 31, 2018 December 31, 2017 Raw materials $ 5,961 $ 4,969 Work-in-process 791 502 Finished goods 38,854 37,933 45,606 43,404 Less reserve for excess and obsolete finished goods (16,734 ) (16,112 ) Inventories, net $ 28,872 $ 27,292
Property and equipment, net	Property and equipment, net consist of the following (in thousands except as indicated): Useful lives (in years) March 31, 2018 December 31, 2017 Surgical instruments 4 $ 52,460 $ 53,198 Machinery and equipment 7 6,012 5,503 Computer equipment 3 3,540 3,500 Office furniture and equipment 5 2,829 2,794 Leasehold improvements various 1,714 1,714 Construction in progress n/a 70 336 66,625 67,045 Less accumulated depreciation and amortization (55,076 ) (54,375 ) Property and equipment, net $ 11,549 $ 12,670
Intangible assets, net	Intangible assets, net consist of the following (in thousands except as indicated): Remaining Avg. Useful lives (in years) March 31, 2018 December 31, 2017 Developed technology 8 $ 26,975 $ 13,876 Intellectual property — 1,004 1,004 License agreements 1 5,738 5,738 Trademarks and trade names — 792 732 Customer-related 2 7,458 7,458 Distribution network 4 4,027 4,027 In process research and development — 8,400 — 54,394 32,835 Less accumulated amortization (27,880 ) (27,587 ) Intangible assets, net $ 26,514 $ 5,248
Schedule of intangible assets, future amortization expense	Future amortization expense related to intangible assets as of March 31, 2018 is as follows (in thousands): Year Ending December 31, Remainder of 2018 $ 1,043 2019 1,426 2020 1,411 2021 1,411 2022 1,411 Thereafter 19,812 $ 26,514
Accrued expenses	Accrued expenses consist of the following (in thousands): March 31, 2018 December 31, 2017 Commissions and sales milestones $ 3,435 $ 3,360 Payroll and payroll related 2,653 2,968 Litigation settlements 4,400 4,400 Accrued professional fees 2,566 1,484 Royalties 1,139 1,269 Restructuring and severance accruals 539 520 Accrued taxes 286 246 Guaranteed collaboration compensation, current — 4,485 Accrued interest 377 376 Acquisition related - contingent consideration 3,200 Other 4,773 3,138 Total accrued expenses $ 23,368 $ 22,246

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Principal Payments on Debt	Principal payments on the Company's debt are as follows as of March 31, 2018 (in thousands): Year Ending December 31, Remainder of 2018 $ 6,502 2019 3,423 2020 3,380 2021 21,667 2022 and thereafter 8,424 Total 43,396 Add: capital lease principal payments 192 Less: unamortized debt discount and debt issuance costs (2,032 ) Total 41,556 Less: current portion of long-term debt (6,891 ) Long-term debt, net of current portion $ 34,665

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Future minimum annual lease payments	Future minimum annual lease payments under such leases are as follows as of March 31, 2018 (in thousands): Year Ending December 31, Operating Capital Remainder of 2018 $ 1,276 $ 70 2019 1,645 37 2020 1,688 37 2021 1,009 37 2022 and thereafter — 37 $ 5,618 218 Less: amount representing interest (26 ) Present value of minimum lease payments 192 Current portion of capital leases (70 ) Capital leases, less current portion $ 122

Acquisition of SafeOp Surgica27

Acquisition of SafeOp Surgical, Inc. (Tables)	3 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
Schedule of Unaudited Pro Forma Operations	The Merger was accounted for using the acquisition method of accounting. The following unaudited pro forma results of operations assume that the Company acquired Three Months Ended March 31, 2018 2017 (in thousands, except per share data) Revenue $ 21,335 $ 28,024 Loss from continuing operations (2,682 ) (6,656 ) Net loss $ (2,744 ) $ (6,747 ) Net loss per share, basic and diluted $ (0.11 ) $ (0.46 )
Schedule of Total Purchase Price	The total purchase price is presented below (in thousands): Cash paid and payable $ 15,103 Common stock issued and issuable 10,756 Note 3,000 Warrants 1,650 Contingent Consideration 3,200 Total $ 33,709
Schedule of Allocation of Purchase Price	The allocation of the purchase price to the assets acquired and liabilities assumed based on their fair values, is as follows (in thousands): Assets acquired: Accounts receivable $ 40 Inventory 192 Prepaid expenses and other current assets 89 Total current assets $ 321 Property and equipment, net 20 Other long-term assets 5 IPR&D 8,400 EPAD Tradename 60 Developed Technology 13,100 Total assets $ 21,906 Liabilities assumed: Accounts payable $ 54 Accrued expenses 148 Deferred tax liability 2,341 Total liabilities $ 2,543 Goodwill 14,346 Total consideration transferred $ 33,709

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Computation of basic and diluted net loss per share for continuing and discontinued operations	The following table presents the computation of basic and diluted net loss per share for continuing and discontinued operations (in thousands, except per share amounts): Three Months Ended March 31, 2018 2017 Numerator: Loss from continuing operations $ (1,854 ) $ (5,424 ) Loss from discontinued operations (62 ) (91 ) Net loss $ (1,916 ) $ (5,515 ) Denominator: Weighted average common shares outstanding 21,212 9,089 Weighted average unvested common shares subject to repurchase — (84 ) Weighted average common shares outstanding—basic and diluted 21,212 9,005 Net loss per share, basic and diluted: Continuing operations $ (0.09 ) $ (0.60 ) Discontinued operations $ (0.00 ) $ (0.01 ) Net loss per share, basic and diluted $ (0.09 ) $ (0.61 )
Weighted-average anti-dilutive securities not included in diluted net loss per share	The anti-dilutive securities not included in diluted net Three Months Ended March 31, 2018 2017 Options to purchase common stock 316 1,164 Unvested restricted share awards — 84 Series A Convertible Preferred Stock 2,505 7,622 Series B Convertible Preferred Stock 5,045 — Convertible Notes 238 — Warrants to purchase common stock 4,874 9,440 12,978 18,310

Stock Benefit Plans and Equit29

Stock Benefit Plans and Equity Transactions (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Total Stock Based Compensation	Total stock-based compensation for the three months ended March 31, 2018 and 2017 is as follows (in thousands): Three Months Ended March 31, 2018 2017 Cost of revenues $ 22 $ 3 Research and development (116 ) 311 Sales and marketing 111 73 General and administrative 602 421 Total $ 619 $ 808
Summary of Common Stock Reserved for Future Issuance	As of March 31, 2018, the Company had reserved shares of its common stock for future issuance as follows (in thousands): March 31, 2018 Stock options outstanding 3,180 Unvested restricted stock award 2,034 Employee stock purchase plan 411 Series A convertible preferred stock 2,022 Series B convertible preferred stock 14,349 Convertible Notes 988 Warrants outstanding 23,182 Merger shares issuable 290 Merger contingently issuable 1,330 Authorized for future grant under the Plans 439 48,225
Summary of Outstanding Warrants	A summary of all outstanding warrants is as follows: Number of Warrants Strike Price 2017 Common Stock Warrants 6,007,090 $ 2.00 2017 Banker Warrants 167,418 $ 2.50 2018 Common Stock Warrants 13,471,851 $ 3.50 Merger Warrants 2,200,000 $ 3.50 Executive 1,327,434 $ 5.00 Other 7,812 $ 19.20 Total 23,181,605

Restructuring (Tables)

Restructuring (Tables)	3 Months Ended
	Mar. 31, 2018
Restructuring And Related Activities [Abstract]
Rollforward of accrued restructuring liability	A rollforward of the accrued restructuring liability is presented below (in thousands): Balance as of January 1, 2018 $ 520 Accrued restructuring charges 398 Payments (379 ) Balance as of March 31, 2018 $ 539

The Company and Basis of Pres31

The Company and Basis of Presentation - Additional Information (Details)	Mar. 09, 2018USD ($)	Mar. 08, 2018USD ($)	Mar. 31, 2018USD ($)	Mar. 31, 2018USD ($)segment	Dec. 31, 2017USD ($)
Company And Basis Of Presentation [Line Items]
Number of reportable segments | segment				1
Proceeds raised from financing transactions			$ 50,000,000
Working capital			56,200,000	$ 56,200,000
Cash			47,645,000	47,645,000	$ 22,466,000
Gross proceeds from equity offering				48,600,000
Private Placement
Company And Basis Of Presentation [Line Items]
Proceeds from private placement			45,200,000
2018 Private Placement
Company And Basis Of Presentation [Line Items]
Proceeds from private placement		$ 45,200
Aggregate consideration received from warrant exercise agreement			4,800,000
SafeOp Surgical, Inc.
Company And Basis Of Presentation [Line Items]
Portion of net proceeds from 2018 private placement and warrant exercise used to fund cash portion of purchase price	$ 13,800,000
SafeOp Surgical, Inc. | 2018 Private Placement
Company And Basis Of Presentation [Line Items]
Portion of net proceeds from 2018 private placement and warrant exercise used to fund cash portion of purchase price			$ 15,100,000	$ 13,800,000

Summary of Significant Accoun32

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Accounts receivable payment terms	30 days
Accounts receivable related to products and services	$ 11,960	$ 14,822

Summary of Significant Accoun33

Summary of Significant Accounting Policies - Reconciliation of Liabilities (Details) - Fair value, inputs, level 3 $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Ending balance	$ 3,200
SafeOp Surgical, Inc.
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Contingent consideration liability recorded upon acquisition of SafeOp	$ 3,200

Select Condensed Consolidated34

Select Condensed Consolidated Balance Sheet Details - Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Accounts receivable	$ 12,013	$ 15,328
Allowance for doubtful accounts	(53)	(506)
Accounts receivable, net	$ 11,960	$ 14,822

Select Condensed Consolidated35

Select Condensed Consolidated Balance Sheet Details - Inventories, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 5,961	$ 4,969
Work-in-process	791	502
Finished goods	38,854	37,933
Inventory, gross, total	45,606	43,404
Less reserve for excess and obsolete finished goods	(16,734)	(16,112)
Inventories, net	$ 28,872	$ 27,292

Select Condensed Consolidated36

Select Condensed Consolidated Balance Sheet Details - Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 66,625		$ 67,045
Less accumulated depreciation and amortization	(55,076)		(54,375)
Property and equipment, net	11,549		12,670
Depreciation	$ 1,500	$ 1,600
Surgical instruments
Property, Plant and Equipment [Line Items]
Useful lives	4 years
Property and equipment, gross	$ 52,460		53,198
Machinery and equipment
Property, Plant and Equipment [Line Items]
Useful lives	7 years
Property and equipment, gross	$ 6,012		5,503
Capital leased assets, gross	$ 2,100		2,100
Computer equipment
Property, Plant and Equipment [Line Items]
Useful lives	3 years
Property and equipment, gross	$ 3,540		3,500
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Useful lives	5 years
Property and equipment, gross	$ 2,829		2,794
Leasehold improvements
Property, Plant and Equipment [Line Items]
Various useful lives of leasehold improvements	various
Property and equipment, gross	$ 1,714		1,714
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 70		$ 336

Select Condensed Consolidated37

Select Condensed Consolidated Balance Sheet Details - Intangible Assets, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Sep. 30, 2017	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	$ 54,394			$ 32,835
Less accumulated amortization	(27,880)			(27,587)
Intangible assets, net	26,514			5,248
Amortization of intangible assets	300	$ 200
Developed technology
Finite-Lived Intangible Assets [Line Items]
Useful lives			8 years
Intangible assets, Gross	26,975			13,876
Intellectual property
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	1,004			1,004
License agreements
Finite-Lived Intangible Assets [Line Items]
Useful lives			1 year
Intangible assets, Gross	5,738			5,738
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	792			732
Customer-related
Finite-Lived Intangible Assets [Line Items]
Useful lives			2 years
Intangible assets, Gross	7,458			7,458
Distribution network
Finite-Lived Intangible Assets [Line Items]
Useful lives			4 years
Intangible assets, Gross	4,027			$ 4,027
In process research and development
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	8,400
SafeOp Surgical, Inc.
Finite-Lived Intangible Assets [Line Items]
Business acquisition, intangible assets recorded	21,600
SafeOp Surgical, Inc. | Developed technology
Finite-Lived Intangible Assets [Line Items]
Business acquisition, intangible assets recorded	$ 13,100
Useful lives	20 years
SafeOp Surgical, Inc. | In process research and development
Finite-Lived Intangible Assets [Line Items]
Business acquisition, intangible assets recorded	$ 8,400

Select Condensed Consolidated38

Select Condensed Consolidated Balance Sheet Details - Schedule of Intangible Assets, Future Amortization Expense (Details) $ in Thousands	Mar. 31, 2018USD ($)
Balance Sheet Related Disclosures [Abstract]
Remainder of 2018	$ 1,043
2,019	1,426
2,020	1,411
2,021	1,411
2,022	1,411
Thereafter	19,812
Total	$ 26,514

Select Condensed Consolidated39

Select Condensed Consolidated Balance Sheet Details - Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Commissions and sales milestones	$ 3,435	$ 3,360
Payroll and payroll related	2,653	2,968
Litigation settlements	4,400	4,400
Accrued professional fees	2,566	1,484
Royalties	1,139	1,269
Restructuring and severance accruals	539	520
Accrued taxes	286	246
Guaranteed collaboration compensation, current		4,485
Accrued interest	377	376
Acquisition related - contingent consideration	3,200
Other	4,773	3,138
Total accrued expenses	$ 23,368	$ 22,246

Discontinued Operations - Addit

Discontinued Operations - Additional Information (Details)	Sep. 01, 2016USD ($)option	Mar. 31, 2018USD ($)	Mar. 31, 2017USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues		$ 21,307,000	$ 27,978,000
Cost of revenues		7,737,000	11,199,000
General and administrative expenses pertaining to discontinued operations		100,000	100,000
Globus facility agreement
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Maximum borrowing capacity	$ 30,000,000
Globus facility agreement | Line of credit
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Line of credit, expiration period	5 years
Supply agreement [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues			4,500,000
Cost of revenues			$ 3,800,000
Contracts revenue		2,100,000
Cost of contract revenues		$ 2,000,000
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

Debt - MidCap Facility Agreemen

Debt - MidCap Facility Agreement (Details) - Amended credit facility with MidCap - USD ($)	Mar. 08, 2018	Mar. 31, 2018	Aug. 31, 2018
Line of Credit Facility [Line Items]
Line of credit facility periodic payments maturity period		2018-08
Unamortized debt discount		$ 1,300,000
Minimum liquidity covenant amount	$ 5,000,000
Latest date of minimum liquidity covenant	2019-03
Maximum
Line of Credit Facility [Line Items]
Effective date of financial covenants of Amended Credit Facility	2019-04
Minimum
Line of Credit Facility [Line Items]
Effective date of financial covenants of Amended Credit Facility	2018-04
Line of credit | Maximum
Line of Credit Facility [Line Items]
Debt default, interest rate increase		5.00%
Forecast
Line of Credit Facility [Line Items]
Monthly term loan payments			$ 300,000
Revolving credit facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 22,500,000
Line of credit		$ 8,400,000
Interest rate		7.66%
Revolving credit facility | LIBOR
Line of Credit Facility [Line Items]
Interest rate description		LIBOR plus 6.0%
Basis spread		6.00%
Term loan
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 5,000,000
Line of credit		$ 1,500,000
Floor on interest rate		9.50%
Interest rate		9.66%
Term loan | LIBOR
Line of Credit Facility [Line Items]
Interest rate description		("LIBOR") plus 8.0%
Basis spread		8.00%

Debt - Globus Facility Agreemen

Debt - Globus Facility Agreement (Details) - USD ($)	Sep. 02, 2018	Mar. 08, 2018	Sep. 01, 2016	Mar. 31, 2018
Second Amendment To Globus Facility Agreement
Debt Instrument [Line Items]
Minimum liquidity covenant amount		$ 5,000,000
Latest date of minimum liquidity covenant		2019-03
Maximum | Second Amendment To Globus Facility Agreement
Debt Instrument [Line Items]
Effective date of financial covenants of Amended Credit Facility		2019-04
Minimum | Second Amendment To Globus Facility Agreement
Debt Instrument [Line Items]
Effective date of financial covenants of Amended Credit Facility		2018-04
Globus facility agreement
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 30,000,000
Unamortized debt discount				$ 700,000
Line of credit | Globus facility agreement
Debt Instrument [Line Items]
Line of credit				30,000,000
Debt instrument, periodic payment				$ 800,000
Line of credit | Globus facility agreement | Maximum
Debt Instrument [Line Items]
Debt default, interest rate increase			5.00%
Line of credit | LIBOR | Globus facility agreement
Debt Instrument [Line Items]
Interest rate description				LIBOR plus 8.0%
Basis spread				8.00%
Line of credit | Forecast | LIBOR | Globus facility agreement
Debt Instrument [Line Items]
Interest rate description	LIBOR plus 13.0%,
Basis spread	13.00%

Debt - Principal Payments on De

Debt - Principal Payments on Debt (Detail) $ in Thousands	Mar. 31, 2018USD ($)
Debt Disclosure [Abstract]
Remainder of 2018	$ 6,502
2,019	3,423
2,020	3,380
2,021	21,667
2022 and thereafter	8,424
Total	43,396
Add: capital lease principal payments	192
Less: unamortized debt discount and debt issuance costs	(2,032)
Total	41,556
Less: current portion of long-term debt	(6,891)
Long-term debt, net of current portion	$ 34,665

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Loss Contingencies [Line Items]
Rent expense	$ 300,000	$ 400,000
Lawsuit expense recorded			$ 100,000
Liability in connection with lawsuit	0
Alphatec Spine, Inc.
Loss Contingencies [Line Items]
Guaranteed obligated minimum royalty payments through 2022 and beyond	$ 6,100,000
Minimum
Loss Contingencies [Line Items]
Lease interest rate	6.40%
Maximum
Loss Contingencies [Line Items]
Lease interest rate	7.64%

Commitments and Contingencies45

Commitments and Contingencies - Future Minimum Annual Lease Payments (Details) $ in Thousands	Mar. 31, 2018USD ($)
Commitments And Contingencies Disclosure [Abstract]
Operating leases Remainder of 2018	$ 1,276
Operating leases 2019	1,645
Operating leases 2020	1,688
Operating leases 2021	1,009
Total Operating leases	5,618
Capital leases Remainder of 2018	70
Capital leases 2019	37
Capital leases 2020	37
Capital leases 2021	37
Capital leases 2022 and thereafter	37
Total Capital leases	218
Less: amount representing interest	(26)
Present value of minimum lease payments	192
Current portion of capital leases	(70)
Capital leases, less current portion	$ 122

Orthotec Settlement - Additiona

Orthotec Settlement - Additional Information (Details)	Jul. 01, 2016USD ($)	Oct. 01, 2014USD ($)	Aug. 13, 2014USD ($)installment	Sep. 30, 2014USD ($)	Apr. 30, 2014USD ($)	Mar. 31, 2014USD ($)	Mar. 31, 2018USD ($)
Loss Contingencies [Line Items]
Litigation settlement, remaining outstanding balance including interest							$ 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	32,900,000
Number of quarterly installments | installment			28
Litigation settlement interest, quarterly installments, amount			$ 1,100,000
Litigation settlement, final installment amount			700,000
Litigation settlement, remaining outstanding balance including interest							24,900,000
Orthotec LLC, litigation settlement | HealthpointCapital, LLC
Loss Contingencies [Line Items]
Judgment assessed by court for (against) company				$ 5,000,000
Payments of settlement	$ 1,000,000						$ 1,100,000
Orthotec LLC, litigation settlement | Beginning fourth quarter of 2014
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
Orthotec LLC, litigation settlement | Final installment
Loss Contingencies [Line Items]
Number of quarterly installments | installment			1

Acquisition of SafeOp Surgica47

Acquisition of SafeOp Surgical, Inc. - Additional Information (Details) - USD ($)	Mar. 09, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017
Developed SSEP Technology
Business Acquisition [Line Items]
Useful lives				8 years
SafeOp Surgical, Inc.
Business Acquisition [Line Items]
Business acquisition date	Mar. 9, 2018
Increase in net loss due to operating expenses			$ 200,000
Cash paid and payable	$ 15,100,000		15,103,000
Cash payment for acquisition	13,800,000
Stock issued for acquisition, value			$ 9,800,000
Closing share price			$ 3.30
Convertible notes issued	$ 3,000,000
Convertible note convertible to common stock	987,578
Number of warrants issued	2,200,000
Exercise price of warrants per share	$ 3.50
Additional shares of common stock issuable subject to performance milestones	1,330,263
Intangible assets			$ 21,600,000
Transaction costs			1,500,000
Additional shares of common stock value issuable subject to performance milestones			4,300,000
SafeOp Surgical, Inc. | EPAD Tradename
Business Acquisition [Line Items]
Intangible assets			$ 60,000
Useful lives			1 year
SafeOp Surgical, Inc. | Developed SSEP Technology
Business Acquisition [Line Items]
Intangible assets			$ 13,100,000
Useful lives			20 years
SafeOp Surgical, Inc. | Forecast
Business Acquisition [Line Items]
Cash payment for acquisition		$ 1,300,000
SafeOp Surgical, Inc. | Ten Days After Submission of an Application for Regulatory Clearance
Business Acquisition [Line Items]
Additional shares of common stock value issuable subject to performance milestones			$ 1,400,000
SafeOp Surgical, Inc. | Ten Days After Receipt of Clearance from Regulatory Authority
Business Acquisition [Line Items]
Additional shares of common stock value issuable subject to performance milestones			$ 2,900,000
SafeOp Surgical, Inc. | Common Stock
Business Acquisition [Line Items]
Stock issued for acquisition	3,265,132		2,975,209

Acquisition of SafeOp Surgica48

Acquisition of SafeOp Surgical, Inc. - Schedule of Unaudited Pro Forma Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Business Combinations [Abstract]
Revenue	$ 21,335	$ 28,024
Loss from continuing operations	(2,682)	(6,656)
Net loss	$ (2,744)	$ (6,747)
Net loss per share, basic and diluted	$ (0.11)	$ (0.46)

Acquisition of SafeOp Surgica49

Acquisition of SafeOp Surgical, Inc. - Schedule of Total Purchase Price (Details) - SafeOp Surgical, Inc. - USD ($) $ in Thousands	Mar. 09, 2018	Mar. 31, 2018
Business Acquisition [Line Items]
Cash paid and payable	$ 15,100	$ 15,103
Common stock issued and issuable		10,756
Note		3,000
Warrants		1,650
Contingent Consideration		3,200
Total		$ 33,709

Acquisition of SafeOp Surgica50

Acquisition of SafeOp Surgical, Inc. - Schedule of Allocation of Purchase Price (Details)	Mar. 31, 2018USD ($)
Liabilities assumed:
Goodwill	$ 14,346,000
SafeOp Surgical, Inc.
Assets acquired:
Accounts receivable	40,000
Inventory	192,000
Prepaid expenses and other current assets	89,000
Total current assets	321,000
Property and equipment, net	20,000
Other long-term assets	5,000
Intangible assets	21,600,000
Total assets	21,906,000
Liabilities assumed:
Accounts payable	54,000
Accrued expenses	148,000
Deferred tax liability	2,341,000
Total liabilities	2,543,000
Goodwill	14,346,000
Total consideration transferred	33,709,000
SafeOp Surgical, Inc. | IPR&D
Assets acquired:
Intangible assets	8,400,000
SafeOp Surgical, Inc. | EPAD Tradename
Assets acquired:
Intangible assets	60,000
SafeOp Surgical, Inc. | Developed technology
Assets acquired:
Intangible assets	$ 13,100,000

Net Loss Per Share - Computatio

Net Loss Per Share - Computation of Basic and Diluted Net Loss Per Share for Continuing and Discontinued Operations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator:
Loss from continuing operations	$ (1,854)	$ (5,424)
Loss from discontinued operations	(62)	(91)
Net loss	$ (1,916)	$ (5,515)
Denominator:
Weighted average common shares outstanding	21,212	9,089
Weighted average unvested common shares subject to repurchase		(84)
Weighted average common shares outstanding—basic and diluted	21,212	9,005
Net loss per share, basic and diluted:
Continuing operations, net loss per share, basic and diluted	$ (0.09)	$ (0.60)
Discontinued operations, net loss per share, basic and diluted	0	(0.01)
Net loss per share, basic and diluted	$ (0.09)	$ (0.61)

Net Loss Per Share - Weighted-A

Net Loss Per Share - Weighted-Average Anti-Dilutive Securities Not Included in Diluted Net Loss Per Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities not included in diluted net loss per share (in shares)	12,978	18,310
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)	316	1,164
Unvested restricted share 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)		84
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)	4,874	9,440
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)	2,505	7,622
Series B 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)	5,045
Convertible Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities not included in diluted net loss per share (in shares)	238

Stock Benefit Plans and Equit53

Stock Benefit Plans and Equity Transactions - Additional Information (Details) - USD ($)	Mar. 08, 2018	Mar. 29, 2017	Mar. 22, 2017	Mar. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Oct. 04, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Common stock reserved for future issuance				48,225,000	48,225,000
Warrants outstanding				23,181,605	23,181,605
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Issuance of common stock upon securities purchase agreement			1,809,628
Common stock purchase price share			$ 2
Series A Convertible Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Preferred stock, shares issued			15,245
Shares issued price per share			$ 1,000
Percentage of outstanding preferred stock shares			75.00%
Number of preferred shares converted					1,274
Number of preferred shares outstanding for being conversion				4,043	4,043
Series A Convertible Preferred Stock | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Preferred stock convertible to common stock			7,622,372
Number of preferred shares converted to common stock					636,997
Number of preferred shares outstanding for being conversion to common stock				2,021,673	2,021,673
2017 Common Stock Warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Exercise price of warrants (dollars per share)				$ 2	$ 2
Number of warrants exercised					400,000
Proceeds from exercise of warrant					$ 900,000
Warrants outstanding				6,007,090	6,007,090
2017 Common Stock Warrants | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Beneficial ownership limitation percentage					4.99%
Beneficial ownership, limitation option, percentage					9.99%
Beneficial ownership limitation notification period					61 days
2017 Common Stock Warrants | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Percentage of outstanding voting stock acquired				50.00%	50.00%
2017 Banker Warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Exercise price of warrants (dollars per share)				$ 2.50	$ 2.50
Warrants outstanding				167,418	167,418
2018 Common Stock Warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Number of warrants issued (in shares)				1,275,000	1,275,000
Exercise price of warrants (dollars per share)				$ 3.50	$ 3.50
Warrants outstanding				13,471,851	13,471,851
2018 Common Stock Warrants | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Percentage of outstanding voting stock acquired				50.00%	50.00%
2017 Private Placement | 2017 Common Stock Warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Exercise price of warrants (dollars per share)			$ 2
Warrant expiration period			5 years
Stockholder approval date					Jun. 15, 2017
2017 Private Placement | 2017 Common Stock Warrants | Common Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Number of warrants issued (in shares)			9,432,000
2017 Private Placement | 2017 Banker Warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Exercise price of warrants (dollars per share)			$ 2.50
Number of warrants exercised					304,182
Proceeds from exercise of warrant					$ 800,000
Warrants outstanding				167,418	167,418
Aggregate gross proceeds for private placement		$ 18,900,000
2017 Private Placement | 2017 Banker Warrants | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Number of warrants issued (in shares)			471,600
2018 Private Placement
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Exercise price of warrants (dollars per share)	$ 3.50
Warrant expiration period	5 years
Proceeds from exercise of warrant				$ 4,800,000
Aggregate gross proceeds for private placement	$ 45,200
2018 Private Placement | Common Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Number of warrants issued (in shares)	12,196,851
2018 Private Placement | Series A Convertible Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Preferred stock, shares issued	45,200
Shares issued price per share	$ 1,000
Preferred stock initial conversion price per share	$ 3.15
Anti-dilution protection period of initial conversion price	1 year
2018 Private Placement | Series A Convertible Preferred Stock | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Preferred stock convertible to common stock	12,617,857
2018 Private Placement | 2017 Common Stock Warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Exercise price of warrants (dollars per share)	$ 2
Number of warrants exercised	1,700,000
Proceeds from exercise of warrant	$ 3,400,000
Warrants outstanding	2,400,000
Remaining warrant exercisable	700,000
2018 Private Placement | 2017 Common Stock Warrants | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Additional proceeds expected to be received from remaining warrant exercises	$ 1,400,000
Certificate of Designation | 2018 Private Placement | Series A Convertible Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Preferred stock convertible to common stock	317
Preferred stock, shares authorized	45,200
Preferred stock, stated value per share	$ 1,000
Research and development | Collaborative Arrangement | Elite Medical Holdings and Pac 3 Surgical
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Decrease in collaboration liability					$ 200,000
Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Common stock reserved for future issuance							3,150,000
Maximum award to be deductible other than options							$ 1,000,000
2017 Distributor Inducement Plan | Board of Directors | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Share authorized grant of warrants						75,000
2017 Distributor Inducement Plan | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Number of warrants issued (in shares)						200,000
Common stock issued					17,000
2017 Distributor Inducement Plan | Common Stock | Board of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Share authorized grant of warrants						50,000

Stock Benefit Plans and Equit54

Stock Benefit Plans and Equity Transactions - Summary of Total Stock Based Compensation (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Total stock-based compensation	$ 619	$ 808
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Total stock-based compensation	22	3
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Total stock-based compensation	(116)	311
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Total stock-based compensation	111	73
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Total stock-based compensation	$ 602	$ 421

Stock Benefit Plans and Equit55

Stock Benefit Plans and Equity Transactions - Summary Common Stock Reserved for Future Issuance (Details) shares in Thousands	Mar. 31, 2018shares
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Common stock reserved for future issuance	48,225
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Common stock reserved for future issuance	3,180
Unvested restricted share awards
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Common stock reserved for future issuance	2,034
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Common stock reserved for future issuance	411
Series A Convertible Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Common stock reserved for future issuance	2,022
Series B Convertible Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Common stock reserved for future issuance	14,349
Convertible Notes
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Common stock reserved for future issuance	988
Warrants Outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Common stock reserved for future issuance	23,182
Merger shares issuable
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Common stock reserved for future issuance	290
Merger contingently issuable
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Common stock reserved for future issuance	1,330
Authorized for Future Grant Under the Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line items]
Common stock reserved for future issuance	439

Stock Benefit Plans and Equit56

Stock Benefit Plans and Equity Transactions - Summary of Outstanding Warrants (Details)	Mar. 31, 2018$ / sharesshares
Class Of Warrant Or Right [Line Items]
Number of Warrants	23,181,605
2017 Common Stock Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	6,007,090
Exercise price of warrants per share | $ / shares	$ 2
2017 Banker Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	167,418
Exercise price of warrants per share | $ / shares	$ 2.50
2018 Common Stock Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	13,471,851
Exercise price of warrants per share | $ / shares	$ 3.50
Merger Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	2,200,000
Exercise price of warrants per share | $ / shares	$ 3.50
Executive Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	1,327,434
Exercise price of warrants per share | $ / shares	$ 5
Other Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	7,812
Exercise price of warrants per share | $ / shares	$ 19.20

Termination and Settlement of57

Termination and Settlement of Elite Medical Holdings and Pac 3 Surgical Collaboration Agreement - Additional Information (Details) - Collaborative Arrangement - Elite Medical Holdings and Pac 3 Surgical - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Feb. 28, 2018	Mar. 31, 2018
Termination And Settlement Of Collaboration Agreement [Line Items]
Payments of settlement	$ 0.4
Gain on contract termination and settlement		$ 6.2

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Income Tax [Line Items]
Unrecognized tax benefits	$ 4,400,000	$ 4,400,000
Changes in unrecognized tax benefits	0	$ 0
Reasonably possible amount of unrecognized tax benefit that could reverse in the next twelve months	$ 100,000
SafeOp Surgical, Inc.
Income Tax [Line Items]
Effective income tax rate	19.80%
Federal statutory income tax rate	21.00%

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	Jul. 01, 2016	Aug. 13, 2014	Sep. 30, 2014	Apr. 30, 2014	Mar. 31, 2014	Mar. 31, 2018	Mar. 31, 2017
Orthotec LLC, litigation settlement
Related Party Transaction [Line Items]
Payments of settlement				$ 15,750	$ 1,750	$ 32,900
Judgment assessed by court for (against) company		$ (49,000)
Orthotec LLC, litigation settlement | HealthpointCapital, LLC
Related Party Transaction [Line Items]
Payments of settlement	$ 1,000					1,100
Judgment assessed by court for (against) company			$ (5,000)
HealthpointCapital, LLC
Related Party Transaction [Line Items]
Incurred expenses (less than $.1 million)						100	$ 100
Payable liability (less than $.1 million)						$ 100

Restructuring - Additional Info

Restructuring - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 398,000	$ 1,231,000
2015 California manufacturing operations restructuring plan
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	0	$ 1,200,000
Employee severance | Severance liability and post employment benefits in connection with Globus transaction
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 400,000

Restructuring - Rollforward of

Restructuring - Rollforward of accrued restructuring liability (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Restructuring And Related Activities [Abstract]
Beginning balance	$ 520
Accrued restructuring charges	398	$ 1,231
Payments	(379)
Ending balance	$ 539

Subsequent events - Additional

Subsequent events - Additional Information (Details) - 2017 Common Stock Warrants - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2018	Mar. 31, 2018
Subsequent Event [Line Items]
Proceeds from exercise of warrant		$ 0.9
Forecast
Subsequent Event [Line Items]
Warrants exercised	1,600,000
Proceeds from exercise of warrant	$ 3.1