SI-BONE (SIBN) 10-Q 9 Aug 22 2022 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Jun. 30, 2022	Jul. 31, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2022
Document Transition Report	false
Entity File Number	001-38701
Entity Registrant Name	SI-BONE, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-2216351
Entity Address, Address Line One	471 El Camino Real
Entity Address, Address Line Two	Suite 101
Entity Address, City or Town	Santa Clara
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95050
City Area Code	408
Local Phone Number	207-0700
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	SIBN
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		34,305,039
Entity Central Index Key	0001459839
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 24,319	$ 63,419
Short-term investments	90,095	83,560
Accounts receivable, net of allowance for doubtful accounts of $255 and $264, respectively	15,118	14,246
Inventory	16,484	11,498
Prepaid expenses and other current assets	2,325	3,143
Total current assets	148,341	175,866
Property and equipment, net	12,810	8,992
Operating lease right-of-use assets	4,611	5,248
Other non-current assets	385	400
TOTAL ASSETS	166,147	190,506
Current liabilities:
Accounts payable	5,141	3,198
Accrued liabilities and other	10,189	12,353
Current portion of long-term borrowings	0	0
Operating lease liabilities, current portion	1,342	1,339
Total current liabilities	16,672	16,890
Long-term borrowings	35,075	34,973
Operating lease liabilities, net of current portion	3,529	4,166
Other long-term liabilities	38	57
TOTAL LIABILITIES	55,314	56,086
Commitments and contingencies (Note 6)
STOCKHOLDERS’ EQUITY
Preferred stock, $0.0001 par value; 5,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.0001 par value; 100,000,000 shares authorized; 34,221,614 and 33,674,085 shares issued and outstanding, respectively	3	3
Additional paid-in capital	442,570	429,914
Accumulated other comprehensive income	32	352
Accumulated deficit	(331,772)	(295,849)
TOTAL STOCKHOLDERS’ EQUITY	110,833	134,420
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 166,147	$ 190,506

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 255	$ 264
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock authorized (in shares)	5,000,000	5,000,000
Preferred stock issued (in shares)	0	0
Preferred stock outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock authorized (in shares)	100,000,000	100,000,000
Common stock issued (in shares)	34,221,614	33,674,085
Common stock outstanding (in shares)	34,221,614	33,674,085

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Revenue	$ 25,585	$ 22,194	$ 48,024	$ 42,636
Cost of goods sold	3,465	2,375	6,448	4,575
Gross profit	22,120	19,819	41,576	38,061
Operating expenses:
Sales and marketing	28,843	23,084	54,448	44,006
Research and development	3,478	3,149	7,058	6,104
General and administrative	7,680	6,551	14,819	12,491
Total operating expenses	40,001	32,784	76,325	62,601
Loss from operations	(17,881)	(12,965)	(34,749)	(24,540)
Interest and other income (expense), net:
Interest income	136	46	209	107
Interest expense	(622)	(1,075)	(1,183)	(2,139)
Other income (expense), net	(146)	13	(200)	349
Net loss	(18,513)	(13,981)	(35,923)	(26,223)
Other comprehensive income (loss):
Changes in foreign currency translation	(14)	35	(14)	(80)
Unrealized gain (loss) on marketable securities	(58)	(5)	(306)	16
Comprehensive loss	$ (18,585)	$ (13,951)	$ (36,243)	$ (26,287)
Net loss per share, basic (in usd per share)	$ (0.54)	$ (0.42)	$ (1.06)	$ (0.80)
Net loss per share, diluted (in usd per share)	$ (0.54)	$ (0.42)	$ (1.06)	$ (0.80)
Weighted-average number of common shares used to compute basic net loss per share (in shares)	34,052,692	32,978,914	33,923,229	32,836,040
Weighted-average number of common shares used to compute diluted net loss per share (in shares)	34,052,692	32,978,914	33,923,229	32,836,040

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Stockholders' equity, beginning of period (in shares) at Dec. 31, 2020		32,583,220
Stockholders' equity, beginning of period at Dec. 31, 2020	$ 169,363	$ 3	$ 408,113	$ 524	$ (239,277)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net of shares withheld (in shares)		93,975
Issuance of common stock upon vesting of restricted stock units	601		601
Issuance of common stock upon vesting of restricted stock units (in shares)		131,339
Stock-based compensation	4,030		4,030
Vesting of early exercised stock options	9		9
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent	(115)			(115)
Net unrealized gain (loss) on marketable securities	21			21
Net loss	(12,242)				(12,242)
Stockholders' equity, end of period (in shares) at Mar. 31, 2021		32,808,534
Stockholders' equity, end of period at Mar. 31, 2021	161,667	$ 3	412,753	430	(251,519)
Stockholders' equity, beginning of period (in shares) at Dec. 31, 2020		32,583,220
Stockholders' equity, beginning of period at Dec. 31, 2020	$ 169,363	$ 3	408,113	524	(239,277)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock related to employee stock purchase plan (in shares)	104,861
Issuance of common stock related to employee stock purchase plan	$ 1,600
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent	(80)
Net unrealized gain (loss) on marketable securities	16
Net loss	(26,223)
Stockholders' equity, end of period (in shares) at Jun. 30, 2021		33,236,270
Stockholders' equity, end of period at Jun. 30, 2021	154,198	$ 3	419,235	460	(265,500)
Stockholders' equity, beginning of period (in shares) at Mar. 31, 2021		32,808,534
Stockholders' equity, beginning of period at Mar. 31, 2021	161,667	$ 3	412,753	430	(251,519)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net of shares withheld (in shares)		140,917
Issuance of common stock upon vesting of restricted stock units	650		650
Issuance of common stock upon vesting of restricted stock units (in shares)		181,958
Issuance of common stock related to employee stock purchase plan (in shares)		104,861
Issuance of common stock related to employee stock purchase plan	1,566		1,566
Stock-based compensation	4,257		4,257
Vesting of early exercised stock options	9		9
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent	35			35
Net unrealized gain (loss) on marketable securities	(5)			(5)
Net loss	(13,981)				(13,981)
Stockholders' equity, end of period (in shares) at Jun. 30, 2021		33,236,270
Stockholders' equity, end of period at Jun. 30, 2021	154,198	$ 3	419,235	460	(265,500)
Stockholders' equity, beginning of period (in shares) at Dec. 31, 2021		33,674,085
Stockholders' equity, beginning of period at Dec. 31, 2021	134,420	$ 3	429,914	352	(295,849)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net of shares withheld (in shares)		34,798
Issuance of common stock upon vesting of restricted stock units	169		169
Issuance of common stock upon vesting of restricted stock units (in shares)		163,480
Stock-based compensation	5,507		5,507
Net unrealized gain (loss) on marketable securities	(248)			(248)
Net loss	(17,410)				(17,410)
Stockholders' equity, end of period (in shares) at Mar. 31, 2022		33,872,363
Stockholders' equity, end of period at Mar. 31, 2022	122,438	$ 3	435,590	104	(313,259)
Stockholders' equity, beginning of period (in shares) at Dec. 31, 2021		33,674,085
Stockholders' equity, beginning of period at Dec. 31, 2021	$ 134,420	$ 3	429,914	352	(295,849)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net of shares withheld (in shares)	39,267
Issuance of common stock related to employee stock purchase plan (in shares)	112,773
Issuance of common stock related to employee stock purchase plan	$ 1,600
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent	(14)
Net unrealized gain (loss) on marketable securities	(306)
Net loss	(35,923)
Stockholders' equity, end of period (in shares) at Jun. 30, 2022		34,221,614
Stockholders' equity, end of period at Jun. 30, 2022	110,833	$ 3	442,570	32	(331,772)
Stockholders' equity, beginning of period (in shares) at Mar. 31, 2022		33,872,363
Stockholders' equity, beginning of period at Mar. 31, 2022	122,438	$ 3	435,590	104	(313,259)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net of shares withheld (in shares)		4,469
Issuance of common stock upon vesting of restricted stock units	30		30
Issuance of common stock upon vesting of restricted stock units (in shares)		232,009
Issuance of common stock related to employee stock purchase plan (in shares)		112,773
Issuance of common stock related to employee stock purchase plan	1,199		1,199
Stock-based compensation	5,751		5,751
Vesting of early exercised stock options	(14)			(14)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent	(14)
Net unrealized gain (loss) on marketable securities	(58)			(58)
Net loss	(18,513)				(18,513)
Stockholders' equity, end of period (in shares) at Jun. 30, 2022		34,221,614
Stockholders' equity, end of period at Jun. 30, 2022	$ 110,833	$ 3	$ 442,570	$ 32	$ (331,772)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities
Net loss	$ (35,923)	$ (26,223)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	11,258	8,287
Depreciation and amortization	1,505	845
Accretion of discount on marketable securities	515	721
Amortization of debt issuance costs	101	175
Loss on sale and disposal of property and equipment	105	125
Changes in operating assets and liabilities:
Accounts receivable	(720)	1,746
Inventory	(4,882)	(2,482)
Prepaid expenses and other assets	851	157
Accounts payable	936	554
Accrued liabilities and other	(2,099)	(1,415)
Net cash used in operating activities	(28,353)	(17,510)
Cash flows from investing activities
Maturities of marketable securities	48,000	56,977
Purchases of marketable securities	(55,356)	(43,337)
Purchases of property and equipment	(4,275)	(4,191)
Net cash (used in) provided by investing activities	(11,631)	9,449
Cash flows from financing activities
Proceeds from issuance of common stock under employee stock purchase plan	1,199	1,566
Proceeds from the exercise of stock options	199	1,251
Net cash provided by financing activities	1,398	2,817
Effect of exchange rate changes on cash and cash equivalents	(514)	(212)
Net decrease in cash and cash equivalents	(39,100)	(5,456)
Cash and cash equivalents at
Beginning of period	63,419	53,581
End of period	24,319	48,125
Supplemental disclosure of non-cash information
Vesting of early exercised stock options	0	18
Unpaid purchases of property and equipment	$ 1,593	$ 106

The Company and Nature of Busin

The Company and Nature of Business	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company and Nature of Business	The Company and Nature of Business SI-BONE, Inc. (the “Company”) was incorporated in the state of Delaware on March 18, 2008 and is headquartered in Santa Clara, California. The Company is a medical device company that has pioneered a proprietary minimally invasive surgical implant system to fuse the sacroiliac joint for treatment of musculoskeletal disorders of the sacropelvic anatomy. The Company introduced its first generation iFuse implant in 2009 in the U.S., in 2010 in certain countries in the European Union, and in 2015 in certain countries in the rest of the world. Risks and Uncertainties The Company is subject to continuing risk and uncertainties as a result of the COVID-19 pandemic, and is closely monitoring the impact of the pandemic on all aspects of its business, including the impacts on its customers, patients that would benefit from procedures involving the Company's products, employees, suppliers, vendors, business partners and distribution channels. Economies worldwide continue to be negatively impacted by the COVID-19 pandemic, in particular with recurrent mutations of the virus, despite advances in vaccines, and the Company anticipates these disruptions will continue. While the Company has not experienced material disruptions to its supply chain to date, certain of its third-party suppliers have faced delays, product shortages and rising costs resulting from disruptions in the global supply chain, primarily related to the instruments. As a result, the Company is continuing to work closely with its manufacturing partners and suppliers, as well as determining alternative sourcing strategies to enable the Company to source key components and maintain appropriate inventory levels to meet customer demand. As such the Company's future results of operations and liquidity could be adversely impacted by a variety of factors related to the COVID-19 pandemic and global supply chain issues, including those discussed in the section entitled "Risk Factors" in this report. As of the date of issuance of these condensed consolidated financial statements, the extent to which the COVID-19 pandemic and global supply chain issues may materially impact the Company's financial condition, liquidity, or results of operations remains uncertain.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP have been condensed or omitted, and accordingly the balance sheet as of December 31, 2021 has been derived from the audited consolidated financial statements at that date but does not include all of the information required by GAAP for complete financial statements. These unaudited interim condensed consolidated financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments that are necessary for a fair statement of the Company’s consolidated financial information. The results of operations for the three and six months ended June 30, 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022 or for any other interim period or for any other future year. The accompanying condensed consolidated financial statements should be read in conjunction with the audited financial statements and related notes thereto for the year ended December 31, 2021 contained in the Company’s Annual Report on Form 10-K filed with the SEC on March 1, 2022. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Significant accounting estimates and management judgments reflected in the condensed consolidated financial statements primarily includes the fair value of performance-based restricted stock unit awards. Estimates are based on historical experience, where applicable and other assumptions believed to be reasonable by the management. Actual results could differ from those estimates. Significant Accounting Policies The Company’s significant accounting policies are disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021. There have been no material changes to these accounting policies, except for the accounting policy related to performance-based restricted stock unit awards noted below that was added to the Company’s significant accounting policies in the first quarter of 2022. Performance-Based Restricted Stock Unit Award s The Company grants restricted stock unit awards subject to market and service vesting conditions to certain executive officers. This type of grant consists of the right to receive shares of common stock, subject to achievement of time-based criteria and certain market-related performance goals over a specified period, as established by the Compensation Committee of the Company’s Board of Directors. For these awards that are subject to market-related performance, the fair value is determined based on the number of shares granted and a Monte Carlo valuation model, which incorporates the probability of the achievement of the market-related performance goals as part of the grant date fair value. If such performance goals are not ultimately met, the expense is not reversed. Stock-based compensation expense is recognized ratably over the requisite service period. Segments The Company's chief operating decision makers are the Chief Executive Officer (“CEO”) and Chief Financial Officer (“CFO”). The CEO and the CFO review financial information presented on a consolidated basis, accompanied by information about revenue by geographic region, for purposes of evaluating financial performance. The Company has one business activity and there are no segment managers who are held accountable for operations, operating results or plans for levels or components below the consolidated unit level. Accordingly, the Company has determined that it has a single reportable and operating segment structure . The Company derives substantially all of its revenue from sales to customers in the U.S. Revenue by geography is based on billing address of the customer. International revenue accounted for less than 10% of the total revenue during the periods presented. Long-lived assets held outside the U.S. are immaterial. Following table summarizes the Company's revenue by geography: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 (in thousands) United States $ 23,771 $ 20,230 $ 44,137 $ 39,000 International 1,814 1,964 3,887 3,636 $ 25,585 $ 22,194 $ 48,024 $ 42,636 Recently Adopted Accounting Standards In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02), which requires the lessee to recognize a lease right-of-use asset and a lease liability for operating leases, initially measured at the present value of lease payments, in its consolidated balance sheet. In the fourth quarter of 2021, the Company adopted ASU 2016-02 using the modified retrospective method with the effective date of January 1, 2021. As a result, the Company has retrospectively changed its previously issued condensed consolidated financial statements as of June 30, 2021 and for the three and six months ended June 30, 2021 as presented in its June 30, 2021 Quarterly Report on Form 10-Q to reflect the adoption of Topic 842 on January 1, 2021. The condensed consolidated financial statements for the three and six months ended June 30, 2021 presented herein differ from the Company’s condensed consolidated financial statements included in its June 30, 2021 Quarterly Report on Form 10-Q, as those financial statements were prepared using the former accounting standard referred to as ASC Topic 840, Leases. The following table summarizes the effect of the adoption of Topic 842 on the condensed consolidated balance sheet as of January 1, 2021: As Previously Reported Impact of Topic 842 Adoption As Adjusted (in thousands) ASSETS Operating lease right-of-use assets $ — $ 3,507 $ 3,507 LIABILITIES AND STOCKHOLDERS’ EQUITY Operating lease liabilities, current portion — 852 852 Operating lease liabilities, net of current portion — 2,933 2,933 Accrued liabilities and other 10,199 (345) 9,854 Accumulated deficit (239,277) 68 (239,209) The adoption of Topic 842 did not have any other material impact on the condensed consolidated financial statements as of June 30, 2021 and for the three and six months ended June 30, 2021. In August 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2020-06, Debt - Debt with Conversion and Other Options (ASC 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40). ASU 2020-06 simplifies the accounting for convertible instruments by removing the beneficial conversion and cash conversion accounting models for convertible instruments and removes certain settlement conditions that are required for contracts to qualify for equity classification. This new standard also simplifies the diluted earnings per share calculations by requiring that an entity use the if-converted method for convertible instruments and requires that the effect of potential share settlement be included in diluted earnings per share calculations when an instrument may be settled in cash or shares. The new standard requires entities to provide expanded disclosures about the terms and features of convertible instruments, how the instruments have been reported in the entity’s financial statements, and information about events, conditions, and circumstances that can affect how to assess the amount or timing of an entity’s future cash flows related to those instruments. The ASU is effective for public companies, excluding entities eligible to be smaller reporting companies, for fiscal years beginning after December 15, 2021. The new standard went effective on January 1, 2022, and it did not impact the Company's consolidated financial statements and related disclosures. In May 2021, the FASB issued ASU 2021-04 “Earnings Per Share (Topic 260), Debt—Modifications and Extinguishments (Subtopic 470-50), Compensation— Stock Compensation (Topic 718), and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815- 40) Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options” ("ASU 2021-04") which clarifies and reduces diversity in an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options that remain equity classified after modification or exchange. An entity should measure the effect of a modification or an exchange of a freestanding equity-classified written call option that remains equity classified after modification or exchange as follows: i) for a modification or an exchange that is a part of or directly related to a modification or an exchange of an existing debt instrument or line-of-credit or revolving-debt arrangements (hereinafter, referred to as a “debt” or “debt instrument”), as the difference between the fair value of the modified or exchanged written call option and the fair value of that written call option immediately before it is modified or exchanged; ii) for all other modifications or exchanges, as the excess, if any, of the fair value of the modified or exchanged written call option over the fair value of that written call option immediately before it is modified or exchanged. The amendments in this update are effective for all entities for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years. An entity should apply the amendments prospectively to modifications or exchanges occurring on or after the effective date of the amendments. The new standard went effective on January 1, 2022, and it did not impact the Company's consolidated financial statements and related disclosures. Recently Accounting Standards Not Yet Effective In March 2022, the FASB issued ASU 2022-02, Financial Instruments - Credit Losses (Topic 326), Troubled Debt Restructurings (“TDRs”) and Vintage Disclosures. ASU 2022-02 eliminates the accounting guidance for TDRs in ASC 310-40, Receivables - Troubled Debt Restructurings by Creditors. In addition, ASU 2022-02 also requires that public business entities disclose current-period gross write-offs by year of origination for financing receivables and net investments in leases within the scope of Subtopic 326-20, Financial Instruments—Credit Losses—Measured at Amortized Cost. The ASU is effective for public companies, excluding entities eligible to be smaller reporting companies, for fiscal years beginning after December 15, 2022. The Company is currently evaluating the impact of applying this guidance on its consolidated financial statements and related disclosures.

Marketable Securities

Marketable Securities	6 Months Ended
	Jun. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities All of the Company's marketable securities were available-for-sale and were classified based on their maturities. Marketable securities with remaining maturities at the date of purchase of three months or less are classified as cash equivalents. Short-term investments are securities that original maturity or remaining maturity is greater than three months and not more than twelve months. Long-term investments are securities for which the original maturity or remaining maturity is greater than twelve months. The table below summarizes the marketable securities: June 30, 2022 Amortized Cost Unrealized Gains Unrealized Losses Aggregate Fair Value (in thousands) Money market funds $ 18,084 $ — $ — $ 18,084 Cash equivalents 18,084 — — 18,084 U.S. treasury securities 56,156 — (257) 55,899 Corporate bonds 20,285 — (84) 20,201 Commercial paper 13,995 — — 13,995 Short-term investments 90,436 — (341) 90,095 Total marketable securities $ 108,520 $ — $ (341) $ 108,179 December 31, 2021 Amortized Cost Unrealized Gains Unrealized Losses Aggregate Fair Value (in thousands) Money market funds $ 57,829 $ — $ — $ 57,829 Cash equivalents 57,829 — — 57,829 U.S. treasury securities 28,064 — (16) 28,048 Corporate bonds 31,558 4 (23) 31,539 Commercial paper 23,973 — — 23,973 Short-term investments 83,595 4 (39) 83,560 Total marketable securities $ 141,424 $ 4 $ (39) $ 141,389 The amortized cost of the Company's available-for-sale securities approximates their fair value. Unrealized losses are generally due to interest rate fluctuations, as opposed to credit quality. However, the Company reviews individual securities that are in an unrealized loss position in order to evaluate whether or not they have experienced or are expected to experience credit losses. During the six months ended June 30, 2022 and 2021, unrealized gains and losses from the investments were not material and were not the result of a decline in credit quality. As a result, the Company did not recognize any credit losses related to its investments and that all unrealized gains and losses on available-for-sale securities are recorded in accumulated other comprehensive income (loss) on the condensed consolidated balance sheets as of June 30, 2022 and December 31, 2021. The Company elected to present accrued interest receivable separately from short-term and long-term investments on its condensed consolidated balance sheets. Accrued interest receivable was $0.3 million as of June 30, 2022, and was recorded in prepaid expenses and other current assets. The Company also elected to exclude accrued interest receivable from the estimation of expected credit losses on its marketable securities and reverse accrued interest receivable through interest income (expense) when amounts are determined to be uncollectible. The Company did not write off any accrued interest receivable as of June 30, 2022 or December 31, 2021.

Fair Value Measurement

Fair Value Measurement	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurement	Fair Value Measurement Carrying amounts of certain of the Company’s financial instruments, including cash equivalents, accounts receivable, accounts payable and accrued liabilities, approximate fair value due to their relatively short maturities and market interest rates, if applicable. The carrying value of the Company’s long-term debt also approximates fair value based on management’s estimation that a current interest rate would not differ materially from the stated rate. There were no other financial assets and liabilities that require fair value hierarchy measurements and disclosures for the periods presented. The table below summarizes the fair value of the Company’s marketable securities measured at fair value on a recurring basis based on the three-tier fair value hierarchy: June 30, 2022 Level 1 Level 2 Level 3 Total (in thousands) Marketable securities Money market funds $ 18,084 $ — $ — $ 18,084 U.S. treasury securities 55,899 — — 55,899 Corporate bonds — 20,201 — 20,201 Commercial paper — 13,995 — 13,995 Total marketable securities $ 73,983 $ 34,196 $ — $ 108,179 December 31, 2021 Level 1 Level 2 Level 3 Total (in thousands) Marketable securities Money market funds $ 57,829 $ — $ — $ 57,829 U.S. treasury securities 28,048 — — 28,048 Corporate bonds — 31,539 — 31,539 Commercial paper — 23,973 — 23,973 Total marketable securities $ 85,877 $ 55,512 $ — $ 141,389

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Balance Sheet Components Inventory As of June 30, 2022, inventory consisted of finished goods of $15.9 million and work -in-progress of $0.6 million . As of December 31, 2021, inventory consisted of finished goods. Property and Equipment, net: June 30, 2022 December 31, 2021 (in thousands) Machinery and equipment $ 12,721 $ 10,573 Construction in progress 5,604 3,657 Computer and office equipment 909 916 Leasehold improvements 1,631 503 Furniture and fixtures 307 309 21,172 15,958 Less: Accumulated depreciation and amortization (8,362) (6,966) $ 12,810 $ 8,992 As of June 30, 2022, construction in progress pertains to the cost of individual components of a custom instrument set used for surgical placement of the Company's products that have not yet been placed into service of $3.8 million and construction costs related to the new lease in Santa Clara of $1.8 million. Depreciation expense was $0.8 million and $0.5 million for the three months ended June 30, 2022 and 2021, respectively, and $1.5 million and $0.8 million for the six months ended June 30, 2022 and 2021, respectively. Accrued Liabilities and Other : June 30, 2022 December 31, 2021 (in thousands) Accrued compensation and related expenses $ 7,927 $ 10,055 Accrued professional services 652 995 Others 1,610 1,303 $ 10,189 $ 12,353 Accounts Receivable and Allowance for Credit Losses: The movement in the allowance for credit losses was as follows: June 30, 2022 December 31, 2021 (in thousands) Balance at beginning of year $ 264 $ 263 Provision — 14 Write-offs (9) (13) Balance at end of year $ 255 $ 264

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Leases The Company has a non-cancelable operating lease for an office building space, located in Santa Clara, California which expires in May 2025 and a building used for research and development and warehouse space in Santa Clara, California which expires in October 2026. The Company also has non-cancelable operating leases for its office building spaces in Gallarate, Italy and Knaresborough, United Kingdom, which expire in August 2027 and December 2025, respectively. The Company also leases vehicles under operating lease arrangements for certain of its personnel in Europe which expire at various times throughout 2022 to 2027. Supplemental information related to lease expense and valuation of the lease assets and lease liabilit ies are as follows: Three Months Ended Six Months Ended 2022 2021 2022 2021 Operating lease expense $ 397 $ 263 $ 806 $ 546 Variable lease expense 119 65 223 106 Total lease expense $ 516 $ 328 $ 1,029 $ 652 Cash paid for amounts included in the measurement of operating lease liabilities $ 396 $ 281 $ 804 $ 566 Leased assets obtained in exchange for new operating lease liabilities $ 77 $ 240 $ 77 $ 277 June 30, 2022 December 31, 2021 Weighted average remaining lease term (in years) 3.51 3.98 Weighted average discount rate 5.76% 5.75% Future minimum lease payments under non-cancelable operating leases as of June 30, 2022 was as follows: Year Ending December 31, (in thousands) Remainder of 2022 $ 800 2023 1,555 2024 1,498 2025 993 2026 529 Thereafter 8 Total operating lease payments 5,383 Less: imputed interest (512) Total operating lease liabilities $ 4,871 As of June 30, 2022, the Company had no operating lease liabilities that had not commenced. Purchase Commitments and Obligations The Company has certain purchase commitments related to its inventory management with certain manufacturing suppliers wherein the Company is required to purchase the amounts forecasted in a blanket purchase order. The contractual obligations represent future cash commitments and liabilities under agreements with third parties and exclude orders for goods and services entered into in the normal course of business that are not enforceable or legally binding. These outstanding commitments amounted to $0.6 million an d $1.2 million as of June 30, 2022 and December 31, 2021, respectively. Indemnification The Company enters into standard indemnification arrangements in the ordinary course of business. Pursuant to these arrangements, the Company indemnifies, holds harmless, and agrees to reimburse the indemnified parties for losses suffered or incurred by the indemnified party, in connection with any trade secret, copyright, patent or other intellectual property infringement claim by any third-party with respect to the Company’s technology. The term of these indemnification agreements is generally perpetual. The maximum potential amount of future payments the Company could be required to make under these agreements is not determinable because it involves claims that may be made against the Company in the future, but have not yet been made. The Company has entered into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers, other than liabilities arising from willful misconduct of the individual. The Company has not incurred costs to defend lawsuits or settle claims related to these indemnification agreements. No liability associated with such indemnifications has been recorded to date. Legal Contingencies

Borrowings

Borrowings	6 Months Ended
	Jun. 30, 2022
Debt Disclosure [Abstract]
Borrowings	Borrowings Term Loan The following table summarizes the outstanding borrowings from the term loan as of periods presented: June 30, 2022 December 31, 2021 (in thousands) Principal outstanding and final fee $ 35,700 $ 35,700 Less: Unamortized debt issuance costs (85) (100) Unaccreted value of final fee (540) (627) Outstanding debt, net of debt issuance costs and unaccreted value of final fee $ 35,075 $ 34,973 Classified as: Long-term borrowings $ 35,075 $ 34,973 In May 29, 2020, the Company entered into a term loan with Solar Capital Partners (“Solar”). Pursuant to the Loan and Security Agreement, Solar provided an aggregate principal amount of $40.0 million term loan (the “Solar Term Loan”). The Solar Term Loan bore interest at a rate per annum equal to 9.40% plus London Interbank Offered Rate (“LIBOR”), payable monthly in arrears. LIBOR means the greater of (i) 0.33% or (ii) one-month LIBOR (or a comparable replacement rate to be determined by the collateral agent if the LIBOR is no longer available), which rate shall reset monthly. The Solar Term Loan included an interest-only period of 36 months through June 2023, and then repaid in equal monthly principal payments plus interest through June 1, 2025. The Company was also obligated to pay a final fee equal to $1.0 million or 2.5% of the aggregate principal amount of the Solar Term Loan, which was fully earned by Solar on the effective date of the Loan and Security Agreement with Solar. With respect to the Solar Term Loan, this final fee was due and payable on the earliest of (i) the maturity date, (ii) the acceleration of the loan balance or (iii) its full prepayment, refinancing, substitution or replacement. The Company paid in full and terminated the Solar Term Loan in August 2021. The effective interest rate related to the Solar Term Loan was 10.6% for three and six months ended June 30, 2021. The outstanding debt as of June 30, 2022 and December 31, 2021 is related to a term loan pursuant to the Loan and Security Agreement dated August 12, 2021 (the “Effective Date”), entered into by the Company with Silicon Valley Bank (“SVB”). Pursuant the agreement, SVB provided an aggregate principal amount of $35.0 million to the Company (the “SVB Term Loan”). The Company used the proceeds of the SVB Term Loan to repay in full and terminate the Solar Term Loan, which was accounted for as debt extinguishment in accordance with the accounting standards. The Company recognized the unamortized debt issuance costs and unaccreted value of final fee of $1.3 million and the prepayment penalty and lender fees of $0.5 million related to Solar Term Loan as a loss on debt extinguishment. The costs and fees are reflected as interest expense in the consolidated statement of operations for the year ended December 31, 2021. The total debt issuance costs of $0.1 million associated with the SVB Term Loan were recorded in the condensed consolidated balance sheet as a direct deduction from the carrying amount of the loan, and are amortized as a component of interest expense using straight-line method over the life of the term loan. The SVB Term Loan matures (the “Maturity Date”) on either (a) August 1, 2025 or (b) August 1, 2026 dependent on the Company’s achievement of a certain financial performance milestone as of December 31, 2022, as set forth in the Loan Agreement. Interest on the SVB Term Loan is payable monthly at an annual rate set at the greater of (a) 5.75% and (b) prime rate as published in the Wall Street Journal plus 2.5%. Commencing on September 1, 2023, the Company will be required to make monthly principal amortization payments. The Company may elect to prepay the SVB Term Loan prior to the Maturity Date subject to a prepayment fee equal to 1% if the prepayment occurs prior to the second anniversary of the Effective Date and 0% if the prepayment occurs on or at any time after the second anniversary of the Effective Date. The SVB Term Loan is secured by substantially all the Company's assets other than the Company's intellectual property. The Company is also obligated to pay a final payment equal to $0.7 million or 2% of the aggregate principal amount of the SVB Term Loan, which is considered fully earned by SVB on the effective date of the Loan and Security Agreement with SVB. This final payment shall be due and payable on the earliest of (i) the Maturity Date, (ii) the full repayment of the loan, (iii) permitted prepayment and mandatory prepayment upon an acceleration as specified in the agreement or (iv) the termination of the agreement. The final payment is included within the long-term borrowings and is accreted to interest expense using straight-line method over the life of the term loan. The effective interest rate related to the SVB Term Loan for the three and six months ended June 30, 2022 was 6.9% and 6.6%, respectively. The table below summarizes the future principal and final fee payments under the SVB Term Loan as of June 30, 2022: Year ending December 31, (in thousands) Remainder of 2022 $ — 2023 7,292 2024 17,500 2025 10,908 2026 — Total principal and final fee payments $ 35,700 The Loan Agreement includes affirmative and negative covenants applicable to the Company and certain of its foreign subsidiaries. The affirmative covenants include, among others, covenants requiring the Company to maintain its legal existence and governmental compliance, deliver certain financial reports, and maintain insurance coverage. The negative covenants include, among others, restrictions regarding transferring collateral, pledging the Company's intellectual property to other parties, engaging in mergers or acquisitions, paying dividends or making other distributions, incurring indebtedness, transacting with affiliates, and entering into certain investments, in each case subject to certain exceptions. As of June 30, 2022, the Company was in compliance with all debt covenants. CARES Act On March 27, 2020, the U.S. federal government enacted the “Coronavirus Aid, Relief and Economic Security (CARES) Act,” which, among other things, allowed employers to defer the deposit and payment of an employer's share of social security taxes through December 31, 2020. The Company recorded a total liability of $0.5 million related to the deferral of the social security taxes that is included in the accrued liabilities and other in the condensed consolidated balance sheets as of June 30, 2022 and December 31, 2021.

Stock-Based Incentive Compensat

Stock-Based Incentive Compensation Plans	6 Months Ended
	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Incentive Compensation Plans	Stock-Based Incentive Compensation Plans Stock Options The table below summarizes the stock option activity for the six months ended June 30, 2022: Number of Weighted- Outstanding as of December 31, 2021 2,009,513 $8.73 Exercised (39,267) 5.09 Canceled and forfeited (14,229) 12.36 Outstanding as of June 30, 2022 1,956,017 10.22 As of June 30, 2022, the unrecognized compensation cost related to stock options was $0.7 million , which is expected to be recognized over a period of approximately 0.5 years. There were no stock options granted during the three and six months ended June 30, 2022 and 2021. Early Exercise of Unvested Stock Options Early exercises of stock options under the Company's 2008 Stock Option Plan are subject to a right of repurchase by the Company of any unvested shares. The repurchase rights lapse over the original vesting period of the options. The Company accounts for the cash received in consideration for the early exercised options as a liability included in accrued liabilities, which is then reclassified to stockholders’ equity as the options vest. As of June 30, 2022 and December 31, 2021, the Company had no shares subject to repurchase. Restricted Stock Units Restricted stock units (“RSUs”) are share awards that entitle the holder to receive freely tradable shares of the Company’s common stock upon vesting. RSUs generally vest over two In January 2022, the Company granted performance-based restricted stock unit awards subject to market and service vesting conditions to certain executive officers under SI-BONE's 2018 Equity Incentive Plan (“PSUs”). The shares subject to the PSUs vest over a three-year performance period beginning January 1, 2022 and ending December 31, 2024. The actual number of PSUs that will vest in each measurement period will be determined by the Compensation Committee based on the Company’s total shareholder return (“TSR”) relative to the TSR of the Median Peer Companies (as defined in the award agreement). The grant date fair value of each stock award with a market condition was determined using the Monte Carlo valuation model. The table below summ arizes the assumptions used to estimate the grant date fair value of the PSUs granted: Six Months Ended June 30, 2022 Expected volatility of common stock 48.9% to 58.7% Expected volatility of peer companies 24.2% to 152.5% Correlation coefficient of peer companies (0.13) to 1.00 Risk-free interest rate 0.4% to 1.2% Dividend yield —% to 1.0% The table below summarizes RSU and PSU activity for the six months ended June 30, 2022: RSUs PSUs Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Outstanding as of December 31, 2021 1,566,522 $25.17 — $— Granted 1,130,467 21.30 155,596 19.50 Vested (395,489) 24.88 — — Canceled and forfeited (129,123) 23.81 — — Outstanding as of June 30, 2022 2,172,377 23.29 155,596 19.50 As of June 30, 2022, the unr ecognized compensation cost related to the RSUs was $42.2 million, which is expected to be recognized over a period of approximately 2.8 years. As of June 30, 2022, the unrecognized compensation cost related to the PSUs was $2.3 million, which is expected to be recognized over a period of approximately 2.5 years. Employee Stock Purchase Plan The Company’s 2018 Employee Stock Purchase Plan (the “ESPP”) allows eligible employees to purchase shares of the Company's common stock through payroll deductions at the price equal to 85% of the lesser of the fair market value of the stock as of the first date or the ending date of each six month offering period. The offering period generally commences in May and November. On March 26, 2020, the Company's Compensation Committee approved the amendment of the terms of future offerings under the ESPP which, among other things, increased the maximum number of shares that may be purchased on any single purchase date, provided for automatic enrollment in a new offering, and provided that the offering which commenced in May 2020 be twelve months in duration and consist of two purchase periods. The fair value of the ESPP shares is estimated using the Black-Scholes option pricing model, which is being amortized over the requisite service period. The Company issued 112,773 and 104,861 shares under ESPP, representing approximately $1.6 million in employee contributions, for the six months ended June 30, 2022 and 2021. As of June 30, 2022 and December 31, 2021, total accumulated ESPP related employee payroll deductions amounted to $0.2 million and $0.3 million, respectively, which were included within accrued compensation and related expenses in the condensed consolidated balance sheets. Stock-Based Compensation The table below presents the detail of stock-based compensation expense amounts included in the condensed consolidated statements of operations: Three Months Ended Six Months Ended 2022 2021 2022 2021 (in thousands) Cost of goods sold $ 117 $ 129 $ 238 $ 303 Sales and marketing 2,746 2,125 5,340 4,024 Research and development 664 404 1,297 823 General and administrative 2,224 1,599 4,383 3,137 $ 5,751 $ 4,257 $ 11,258 $ 8,287

Net Loss Per Share of Common St

Net Loss Per Share of Common Stock	6 Months Ended
	Jun. 30, 2022
Earnings Per Share [Abstract]
Net Loss Per Share of Common Stock	Net Loss Per Share of Common Stock The table below summarizes the computation of basic and diluted net loss per share: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 (in thousands, except share and per share data) Net loss $ (18,513) $ (13,981) $ (35,923) $ (26,223) Weighted-average shares used to compute basic and diluted net loss per share 34,052,692 32,978,914 33,923,229 32,836,040 Net loss per share, basic and diluted $ (0.54) $ (0.42) $ (1.06) $ (0.80) Because the Company has reported a net loss in all periods presented, outstanding stock options, restricted stock units, shares subject to repurchase, ESPP purchase rights and common stock warrants are anti-dilutive and therefore diluted net loss per common share is the same as basic net loss per common share for the periods presented. The following anti-dilutive common stock equivalents were excluded from the computation of diluted net loss per share for the periods presented: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Stock options 1,956,017 2,147,895 1,956,017 2,147,895 Restricted stock units 2,172,377 1,719,364 2,172,377 1,719,364 Shares subject to repurchase — 1,945 — 1,945 ESPP purchase rights 59,688 34,070 59,688 34,070 Common stock warrants 118,122 118,122 118,122 118,122 4,306,204 4,021,396 4,306,204 4,021,396

Related Party Transaction

Related Party Transaction	6 Months Ended
	Jun. 30, 2022
Related Party Transactions [Abstract]
Related Party Transaction	Related Party Transaction On February 24, 2020, the Company entered into a joint development agreement (the “Development Agreement”) with SeaSpine Orthopedics Corporation (“SeaSpine”) to develop a next generation device for sacropelvic fixation. Mr. Keith Valentine, who serves as the President, Chief Executive Officer and a member of the board of directors of SeaSpine, also serves as a member of the Company's Board of Directors since August 2015. On April 27, 2021, Addendum No.1 to the Development Agreement was entered into by and between the Company and SeaSpine to extend certain obligations as described under the Development Agreement to a consultant of the Company. Pursuant to the development plan, SeaSpine shall use reasonable efforts to assist in the development of the potential product offering, including licensing certain existing intellectual property to be incorporated into such product. Under the terms of the Development Agreement, the Company agreed to make monthly payments to SeaSpine to reimburse for full time resources employed by SeaSpine responsible to conduct the development activities. For the three months ended June 30, 2022 and 2021, the Company exp ensed $— and $13,854, respectively, of the reimbursement charges from SeaSpine. For the six months ended June 30, 2022 and 2021, the Company expensed $6,225 and $23,854, respectively, of the reimbursement charges from SeaSpine. The reimbursement charges were recorded within research and development expense in the condensed consolidated statements of operations . Certain intellectual property developed pursuant to the project plan will be owned by the Company, certain intellectual property developed pursuant to the project plan will be owned by SeaSpine, and other intellectual property developed pursuant to the project plan will be jointly owned by SeaSpine and the Company. The Company also agreed to provide SeaSpine a royalty-free, worldwide, perpetual, non-exclusive license of certain of the Company's intellectual property incorporated into the product to be developed. The Company also agreed to pay SeaSpine a product royalty, in an amount specified in the Development Agreement, for each resulting product sold for a period of 10 years beginning on the initial market launch. The term of the Development Agreement shall continue until the expiration of all royalty terms, unless earlier terminated by either party, as provided for by the Development Agreement. The Company recorded an immaterial amount of royalty for the three and six months ended June 30, 2022. No royalties were recorded in fiscal year 2021. The outstanding liability to SeaSpine as of June 30, 2022 was approximately $2,000 and was recorded within accrued liabilities and other in the condensed consolidated balance sheet. There was no outstanding liability to SeaSpine as of December 31, 2021

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesIn determining quarterly provisions for income taxes, the Company uses the annual estimated effective tax rate applied to the actual year-to-date profit or loss, adjusted for discrete items arising in that quarter. The Company updates its estimate of its annual effective tax rate at the end of each quarterly period. The estimate takes into account annual forecasted income (loss) before income taxes, the geographic mix of income (loss) before income taxes and any significant permanent tax items. The Company did not have provision for income taxes for the three and six months ended June 30, 2022 and 2021. The income taxes for the six months ended June 30, 2022, reflected the impact of a change in U.S. tax law effective January 1, 2022, which requires the capitalization and amortization of research and experimental expenditures incurred after December 31, 2021. Under the Tax Cuts and Jobs Act, for tax years beginning after December 31, 2021, taxpayers are required to capitalize and amortize certain research and experimental expenditures that are paid or incurred in connection with their trade or business. Due to the expected tax loss, the provision did not have tax impact to the quarter. The Company continues to maintain a full valuation allowance against its net deferred tax assets due to the uncertainty surrounding realization of such assets. The Company accounts for the uncertainty in income taxes by utilizing a comprehensive model for the recognition, measurement, presentation and disclosure in financial statements of any uncertain tax positions that have been taken or are expected to be taken on an income tax return. There had been no changes in the estimated uncertain tax benefits recorded as of June 30, 2022

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Basis of Presentation	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP have been condensed or omitted, and accordingly the balance sheet as of December 31, 2021 has been derived from the audited consolidated financial statements at that date but does not include all of the information required by GAAP for complete financial statements.
Principles of Consolidation	These unaudited interim condensed consolidated financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments that are necessary for a fair statement of the Company’s consolidated financial information. The results of operations for the three and six months ended June 30, 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022 or for any other interim period or for any other future year.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Significant accounting estimates and management judgments reflected in the condensed consolidated financial statements primarily includes the fair value of performance-based restricted stock unit awards. Estimates are based on historical experience, where applicable and other assumptions believed to be reasonable by the management. Actual results could differ from those estimates.
Performance-Based Restricted Stock Unit Awards	Performance-Based Restricted Stock Unit Award s The Company grants restricted stock unit awards subject to market and service vesting conditions to certain executive officers. This type of grant consists of the right to receive shares of common stock, subject to achievement of time-based criteria and certain market-related performance goals over a specified period, as established by the Compensation Committee of the Company’s Board of Directors. For these awards that are subject to market-related performance, the fair value is determined based on the number of shares granted and a Monte Carlo valuation model, which incorporates the probability of the achievement of the market-related performance goals as part of the grant date fair value. If such performance goals are not ultimately met, the expense is not reversed. Stock-based compensation expense is recognized ratably over the requisite service period.
Segments	Segments The Company's chief operating decision makers are the Chief Executive Officer (“CEO”) and Chief Financial Officer (“CFO”). The CEO and the CFO review financial information presented on a consolidated basis, accompanied by information about revenue by geographic region, for purposes of evaluating financial performance. The Company has one business activity and there are no segment managers who are held accountable for operations, operating results or plans for levels or components below the consolidated unit level. Accordingly, the Company has determined that it has a single reportable and operating segment structure .
Recently Adopted Accounting Standards and Recent Accounting Standards Not Yet Effective	Recently Adopted Accounting Standards In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02), which requires the lessee to recognize a lease right-of-use asset and a lease liability for operating leases, initially measured at the present value of lease payments, in its consolidated balance sheet. In the fourth quarter of 2021, the Company adopted ASU 2016-02 using the modified retrospective method with the effective date of January 1, 2021. As a result, the Company has retrospectively changed its previously issued condensed consolidated financial statements as of June 30, 2021 and for the three and six months ended June 30, 2021 as presented in its June 30, 2021 Quarterly Report on Form 10-Q to reflect the adoption of Topic 842 on January 1, 2021. The condensed consolidated financial statements for the three and six months ended June 30, 2021 presented herein differ from the Company’s condensed consolidated financial statements included in its June 30, 2021 Quarterly Report on Form 10-Q, as those financial statements were prepared using the former accounting standard referred to as ASC Topic 840, Leases. The following table summarizes the effect of the adoption of Topic 842 on the condensed consolidated balance sheet as of January 1, 2021: As Previously Reported Impact of Topic 842 Adoption As Adjusted (in thousands) ASSETS Operating lease right-of-use assets $ — $ 3,507 $ 3,507 LIABILITIES AND STOCKHOLDERS’ EQUITY Operating lease liabilities, current portion — 852 852 Operating lease liabilities, net of current portion — 2,933 2,933 Accrued liabilities and other 10,199 (345) 9,854 Accumulated deficit (239,277) 68 (239,209) The adoption of Topic 842 did not have any other material impact on the condensed consolidated financial statements as of June 30, 2021 and for the three and six months ended June 30, 2021. In August 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2020-06, Debt - Debt with Conversion and Other Options (ASC 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40). ASU 2020-06 simplifies the accounting for convertible instruments by removing the beneficial conversion and cash conversion accounting models for convertible instruments and removes certain settlement conditions that are required for contracts to qualify for equity classification. This new standard also simplifies the diluted earnings per share calculations by requiring that an entity use the if-converted method for convertible instruments and requires that the effect of potential share settlement be included in diluted earnings per share calculations when an instrument may be settled in cash or shares. The new standard requires entities to provide expanded disclosures about the terms and features of convertible instruments, how the instruments have been reported in the entity’s financial statements, and information about events, conditions, and circumstances that can affect how to assess the amount or timing of an entity’s future cash flows related to those instruments. The ASU is effective for public companies, excluding entities eligible to be smaller reporting companies, for fiscal years beginning after December 15, 2021. The new standard went effective on January 1, 2022, and it did not impact the Company's consolidated financial statements and related disclosures. In May 2021, the FASB issued ASU 2021-04 “Earnings Per Share (Topic 260), Debt—Modifications and Extinguishments (Subtopic 470-50), Compensation— Stock Compensation (Topic 718), and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815- 40) Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options” ("ASU 2021-04") which clarifies and reduces diversity in an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options that remain equity classified after modification or exchange. An entity should measure the effect of a modification or an exchange of a freestanding equity-classified written call option that remains equity classified after modification or exchange as follows: i) for a modification or an exchange that is a part of or directly related to a modification or an exchange of an existing debt instrument or line-of-credit or revolving-debt arrangements (hereinafter, referred to as a “debt” or “debt instrument”), as the difference between the fair value of the modified or exchanged written call option and the fair value of that written call option immediately before it is modified or exchanged; ii) for all other modifications or exchanges, as the excess, if any, of the fair value of the modified or exchanged written call option over the fair value of that written call option immediately before it is modified or exchanged. The amendments in this update are effective for all entities for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years. An entity should apply the amendments prospectively to modifications or exchanges occurring on or after the effective date of the amendments. The new standard went effective on January 1, 2022, and it did not impact the Company's consolidated financial statements and related disclosures. Recently Accounting Standards Not Yet Effective In March 2022, the FASB issued ASU 2022-02, Financial Instruments - Credit Losses (Topic 326), Troubled Debt Restructurings (“TDRs”) and Vintage Disclosures. ASU 2022-02 eliminates the accounting guidance for TDRs in ASC 310-40, Receivables - Troubled Debt Restructurings by Creditors. In addition, ASU 2022-02 also requires that public business entities disclose current-period gross write-offs by year of origination for financing receivables and net investments in leases within the scope of Subtopic 326-20, Financial Instruments—Credit Losses—Measured at Amortized Cost. The ASU is effective for public companies, excluding entities eligible to be smaller reporting companies, for fiscal years beginning after December 15, 2022. The Company is currently evaluating the impact of applying this guidance on its consolidated financial statements and related disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Summary of the effect of the adoption of Topic 842	The following table summarizes the effect of the adoption of Topic 842 on the condensed consolidated balance sheet as of January 1, 2021: As Previously Reported Impact of Topic 842 Adoption As Adjusted (in thousands) ASSETS Operating lease right-of-use assets $ — $ 3,507 $ 3,507 LIABILITIES AND STOCKHOLDERS’ EQUITY Operating lease liabilities, current portion — 852 852 Operating lease liabilities, net of current portion — 2,933 2,933 Accrued liabilities and other 10,199 (345) 9,854 Accumulated deficit (239,277) 68 (239,209)
Schedule of Revenue by Geography	Following table summarizes the Company's revenue by geography: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 (in thousands) United States $ 23,771 $ 20,230 $ 44,137 $ 39,000 International 1,814 1,964 3,887 3,636 $ 25,585 $ 22,194 $ 48,024 $ 42,636

Marketable Securities (Tables)

Marketable Securities (Tables)	6 Months Ended
	Jun. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Schedule of Marketable Securities	The table below summarizes the marketable securities: June 30, 2022 Amortized Cost Unrealized Gains Unrealized Losses Aggregate Fair Value (in thousands) Money market funds $ 18,084 $ — $ — $ 18,084 Cash equivalents 18,084 — — 18,084 U.S. treasury securities 56,156 — (257) 55,899 Corporate bonds 20,285 — (84) 20,201 Commercial paper 13,995 — — 13,995 Short-term investments 90,436 — (341) 90,095 Total marketable securities $ 108,520 $ — $ (341) $ 108,179 December 31, 2021 Amortized Cost Unrealized Gains Unrealized Losses Aggregate Fair Value (in thousands) Money market funds $ 57,829 $ — $ — $ 57,829 Cash equivalents 57,829 — — 57,829 U.S. treasury securities 28,064 — (16) 28,048 Corporate bonds 31,558 4 (23) 31,539 Commercial paper 23,973 — — 23,973 Short-term investments 83,595 4 (39) 83,560 Total marketable securities $ 141,424 $ 4 $ (39) $ 141,389

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Schedule of Marketable Securities Measured at Fair Value on Recurring Basis	The table below summarizes the fair value of the Company’s marketable securities measured at fair value on a recurring basis based on the three-tier fair value hierarchy: June 30, 2022 Level 1 Level 2 Level 3 Total (in thousands) Marketable securities Money market funds $ 18,084 $ — $ — $ 18,084 U.S. treasury securities 55,899 — — 55,899 Corporate bonds — 20,201 — 20,201 Commercial paper — 13,995 — 13,995 Total marketable securities $ 73,983 $ 34,196 $ — $ 108,179 December 31, 2021 Level 1 Level 2 Level 3 Total (in thousands) Marketable securities Money market funds $ 57,829 $ — $ — $ 57,829 U.S. treasury securities 28,048 — — 28,048 Corporate bonds — 31,539 — 31,539 Commercial paper — 23,973 — 23,973 Total marketable securities $ 85,877 $ 55,512 $ — $ 141,389

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Property and Equipment, Net	Property and Equipment, net: June 30, 2022 December 31, 2021 (in thousands) Machinery and equipment $ 12,721 $ 10,573 Construction in progress 5,604 3,657 Computer and office equipment 909 916 Leasehold improvements 1,631 503 Furniture and fixtures 307 309 21,172 15,958 Less: Accumulated depreciation and amortization (8,362) (6,966) $ 12,810 $ 8,992
Schedule of Accrued Liabilities and Other	Accrued Liabilities and Other : June 30, 2022 December 31, 2021 (in thousands) Accrued compensation and related expenses $ 7,927 $ 10,055 Accrued professional services 652 995 Others 1,610 1,303 $ 10,189 $ 12,353
Schedule of Accounts Receivable and Allowance for Credit Losses	Accounts Receivable and Allowance for Credit Losses: The movement in the allowance for credit losses was as follows: June 30, 2022 December 31, 2021 (in thousands) Balance at beginning of year $ 264 $ 263 Provision — 14 Write-offs (9) (13) Balance at end of year $ 255 $ 264

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Supplemental information related to lease expense and valuation of lease assets and lease liabilities	Supplemental information related to lease expense and valuation of the lease assets and lease liabilit ies are as follows: Three Months Ended Six Months Ended 2022 2021 2022 2021 Operating lease expense $ 397 $ 263 $ 806 $ 546 Variable lease expense 119 65 223 106 Total lease expense $ 516 $ 328 $ 1,029 $ 652 Cash paid for amounts included in the measurement of operating lease liabilities $ 396 $ 281 $ 804 $ 566 Leased assets obtained in exchange for new operating lease liabilities $ 77 $ 240 $ 77 $ 277 June 30, 2022 December 31, 2021 Weighted average remaining lease term (in years) 3.51 3.98 Weighted average discount rate 5.76% 5.75%
Future minimum lease payments under non-cancelable operating leases	Future minimum lease payments under non-cancelable operating leases as of June 30, 2022 was as follows: Year Ending December 31, (in thousands) Remainder of 2022 $ 800 2023 1,555 2024 1,498 2025 993 2026 529 Thereafter 8 Total operating lease payments 5,383 Less: imputed interest (512) Total operating lease liabilities $ 4,871

Borrowings (Tables)

Borrowings (Tables)	6 Months Ended
	Jun. 30, 2022
Debt Disclosure [Abstract]
Schedule of Outstanding Borrowings	The following table summarizes the outstanding borrowings from the term loan as of periods presented: June 30, 2022 December 31, 2021 (in thousands) Principal outstanding and final fee $ 35,700 $ 35,700 Less: Unamortized debt issuance costs (85) (100) Unaccreted value of final fee (540) (627) Outstanding debt, net of debt issuance costs and unaccreted value of final fee $ 35,075 $ 34,973 Classified as: Long-term borrowings $ 35,075 $ 34,973
Schedule of Future Principal and Final Fee Payments	The table below summarizes the future principal and final fee payments under the SVB Term Loan as of June 30, 2022: Year ending December 31, (in thousands) Remainder of 2022 $ — 2023 7,292 2024 17,500 2025 10,908 2026 — Total principal and final fee payments $ 35,700

Stock-Based Incentive Compens_2

Stock-Based Incentive Compensation Plans (Tables)	6 Months Ended
	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Schedule of Stock Option Activity	The table below summarizes the stock option activity for the six months ended June 30, 2022: Number of Weighted- Outstanding as of December 31, 2021 2,009,513 $8.73 Exercised (39,267) 5.09 Canceled and forfeited (14,229) 12.36 Outstanding as of June 30, 2022 1,956,017 10.22
Schedule of Share-based Payment Award, Equity Instruments Other Than Options, Valuation Assumptions	The table below summarizes the assumptions used to estimate the grant date fair value of the PSUs granted: Six Months Ended June 30, 2022 Expected volatility of common stock 48.9% to 58.7% Expected volatility of peer companies 24.2% to 152.5% Correlation coefficient of peer companies (0.13) to 1.00 Risk-free interest rate 0.4% to 1.2% Dividend yield —% to 1.0%
Schedule of Restricted Stock Unit Activity	The table below summarizes RSU and PSU activity for the six months ended June 30, 2022: RSUs PSUs Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Outstanding as of December 31, 2021 1,566,522 $25.17 — $— Granted 1,130,467 21.30 155,596 19.50 Vested (395,489) 24.88 — — Canceled and forfeited (129,123) 23.81 — — Outstanding as of June 30, 2022 2,172,377 23.29 155,596 19.50
Schedule of Performance-based Restricted Stock Unit Activity Arrangement	The table below summarizes RSU and PSU activity for the six months ended June 30, 2022: RSUs PSUs Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Outstanding as of December 31, 2021 1,566,522 $25.17 — $— Granted 1,130,467 21.30 155,596 19.50 Vested (395,489) 24.88 — — Canceled and forfeited (129,123) 23.81 — — Outstanding as of June 30, 2022 2,172,377 23.29 155,596 19.50
Schedule of Stock-Based Compensation	The table below presents the detail of stock-based compensation expense amounts included in the condensed consolidated statements of operations: Three Months Ended Six Months Ended 2022 2021 2022 2021 (in thousands) Cost of goods sold $ 117 $ 129 $ 238 $ 303 Sales and marketing 2,746 2,125 5,340 4,024 Research and development 664 404 1,297 823 General and administrative 2,224 1,599 4,383 3,137 $ 5,751 $ 4,257 $ 11,258 $ 8,287

Net Loss Per Share of Common _2

Net Loss Per Share of Common Stock (Tables)	6 Months Ended
	Jun. 30, 2022
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Loss per Share	The table below summarizes the computation of basic and diluted net loss per share: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 (in thousands, except share and per share data) Net loss $ (18,513) $ (13,981) $ (35,923) $ (26,223) Weighted-average shares used to compute basic and diluted net loss per share 34,052,692 32,978,914 33,923,229 32,836,040 Net loss per share, basic and diluted $ (0.54) $ (0.42) $ (1.06) $ (0.80)
Schedule of Anti-dilutive Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share	The following anti-dilutive common stock equivalents were excluded from the computation of diluted net loss per share for the periods presented: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Stock options 1,956,017 2,147,895 1,956,017 2,147,895 Restricted stock units 2,172,377 1,719,364 2,172,377 1,719,364 Shares subject to repurchase — 1,945 — 1,945 ESPP purchase rights 59,688 34,070 59,688 34,070 Common stock warrants 118,122 118,122 118,122 118,122 4,306,204 4,021,396 4,306,204 4,021,396

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Revenue by Geography (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Revenue	$ 25,585	$ 22,194	$ 48,024	$ 42,636
United States
Disaggregation of Revenue [Line Items]
Revenue	23,771	20,230	44,137	39,000
International
Disaggregation of Revenue [Line Items]
Revenue	$ 1,814	$ 1,964	$ 3,887	$ 3,636

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Balance Sheet Updates (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jan. 01, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 4,611	$ 5,248	$ 3,507
Operating lease liabilities, current portion	1,342	1,339	852
Operating lease liabilities, net of current portion	3,529	4,166	2,933
Accrued liabilities and other	10,189	12,353	9,854
Accumulated deficit	$ (331,772)	$ (295,849)	(239,209)
As Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets			0
Operating lease liabilities, current portion			0
Operating lease liabilities, net of current portion			0
Accrued liabilities and other			10,199
Accumulated deficit			(239,277)
Impact of Topic 842 Adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets			3,507
Operating lease liabilities, current portion			852
Operating lease liabilities, net of current portion			2,933
Accrued liabilities and other			(345)
Accumulated deficit			$ 68

Marketable Securities (Details)

Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Cash equivalents
Carrying Value	$ 18,084	$ 57,829
Short-term investments
Amortized Cost	90,436	83,595
Unrealized Gains	0	4
Unrealized Losses	(341)	(39)
Aggregate Fair Value	90,095	83,560
Total marketable securities, Amortized Cost	108,520	141,424
Total marketable securities, Unrealized Gains	0	4
Total marketable securities, Unrealized Losses	(341)	(39)
Total marketable securities, Aggregate Fair Value	108,179	141,389
Accrued interest receivable	300
Money market funds
Cash equivalents
Carrying Value	18,084	57,829
U.S. treasury securities
Short-term investments
Amortized Cost	56,156	28,064
Unrealized Gains	0	0
Unrealized Losses	(257)	(16)
Aggregate Fair Value	55,899	28,048
Corporate bonds
Short-term investments
Amortized Cost	20,285	31,558
Unrealized Gains	0	4
Unrealized Losses	(84)	(23)
Aggregate Fair Value	20,201	31,539
Commercial paper
Short-term investments
Amortized Cost	13,995	23,973
Unrealized Gains	0	0
Unrealized Losses	0	0
Aggregate Fair Value	$ 13,995	$ 23,973

Fair Value Measurement (Details

Fair Value Measurement (Details) - Recurring - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Marketable securities
Marketable securities	$ 108,179	$ 141,389
Money market funds
Marketable securities
Marketable securities	18,084	57,829
U.S. treasury securities
Marketable securities
Marketable securities	55,899	28,048
Corporate bonds
Marketable securities
Marketable securities	20,201	31,539
Commercial paper
Marketable securities
Marketable securities	13,995	23,973
Level 1
Marketable securities
Marketable securities	73,983	85,877
Level 1 | Money market funds
Marketable securities
Marketable securities	18,084	57,829
Level 1 | U.S. treasury securities
Marketable securities
Marketable securities	55,899	28,048
Level 1 | Corporate bonds
Marketable securities
Marketable securities	0	0
Level 1 | Commercial paper
Marketable securities
Marketable securities	0	0
Level 2
Marketable securities
Marketable securities	34,196	55,512
Level 2 | Money market funds
Marketable securities
Marketable securities	0	0
Level 2 | U.S. treasury securities
Marketable securities
Marketable securities	0	0
Level 2 | Corporate bonds
Marketable securities
Marketable securities	20,201	31,539
Level 2 | Commercial paper
Marketable securities
Marketable securities	13,995	23,973
Level 3
Marketable securities
Marketable securities	0	0
Level 3 | Money market funds
Marketable securities
Marketable securities	0	0
Level 3 | U.S. treasury securities
Marketable securities
Marketable securities	0	0
Level 3 | Corporate bonds
Marketable securities
Marketable securities	0	0
Level 3 | Commercial paper
Marketable securities
Marketable securities	$ 0	$ 0

Balance Sheet Components - Narr

Balance Sheet Components - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Inventory, finished goods, gross	$ 15,900		$ 15,900
Inventory, work in process, gross	600		600
Property and equipment, gross	21,172		21,172		$ 15,958
Depreciation expense	800	$ 500	1,500	$ 800
Construction in progress, surgical placement instrument set
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,800		3,800
Construction in Progress, Santa Clara Lease
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,800		$ 1,800

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Property and Equipment, Net
Property and equipment, gross	$ 21,172	$ 15,958
Less: Accumulated depreciation and amortization	(8,362)	(6,966)
Property and equipment, net	12,810	8,992
Machinery and equipment
Property and Equipment, Net
Property and equipment, gross	12,721	10,573
Construction in progress
Property and Equipment, Net
Property and equipment, gross	5,604	3,657
Construction in progress, surgical placement instrument set
Property and Equipment, Net
Property and equipment, gross	3,800
Computer and office equipment
Property and Equipment, Net
Property and equipment, gross	909	916
Leasehold improvements
Property and Equipment, Net
Property and equipment, gross	1,631	503
Furniture and fixtures
Property and Equipment, Net
Property and equipment, gross	$ 307	$ 309

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Liabilities and Other (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jan. 01, 2021
Accrued Liabilities and Other
Accrued compensation and related expenses	$ 7,927	$ 10,055
Accrued professional services	652	995
Others	1,610	1,303
Accrued liabilities and other	$ 10,189	$ 12,353	$ 9,854

Balance Sheet Components - Acco

Balance Sheet Components - Accounts Receivable and Allowance for Credit Losses (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of year	$ 264	$ 263
Provision	0	14
Write-offs	(9)	(13)
Balance at end of year	$ 255	$ 264

Commitment and Contingencies -

Commitment and Contingencies - Supplemental Information Related to Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Operating lease expense	$ 397	$ 263	$ 806	$ 546
Variable lease expense	119	65	223	106
Total lease expense	516	328	1,029	652
Cash paid for amounts included in the measurement of operating lease liabilities	396	281	804	566
Leased assets obtained in exchange for new operating lease liabilities	$ 77	$ 240	$ 77	$ 277
Weighted average remaining lease term (in years)	3 years 6 months 3 days		3 years 6 months 3 days		3 years 11 months 23 days
Weighted average discount rate	5.76%		5.76%		5.75%

Commitments and Contingencies -

Commitments and Contingencies - Aggregate Future Minimum Lease Payments (Details) $ in Thousands	Jun. 30, 2022 USD ($)
Aggregate Future Minimum Lease Payments
Remainder of 2022	$ 800
2023	1,555
2024	1,498
2025	993
2026	529
Thereafter	8
Total operating lease payments	5,383
Less: imputed interest	(512)
Total operating lease liabilities	$ 4,871

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details) - USD ($)	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Other Commitments [Line Items]
Purchase commitments related to inventory management and training materials	$ 600,000	$ 1,200,000
Indemnification Agreement
Other Commitments [Line Items]
Costs to defend lawsuits or settle claims	0
Liability associated with indemnifications	$ 0

Borrowings - Summary of Borrowi

Borrowings - Summary of Borrowings (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
Principal outstanding and final fee	$ 35,700	$ 35,700
Less: Unamortized debt issuance costs	(85)	(100)
Unaccreted value of final fee	(540)	(627)
Outstanding debt, net of debt issuance costs and unaccreted value of final fee	35,075	34,973
Long-term borrowings	$ 35,075	$ 34,973

Borrowings - Narrative (Details

Borrowings - Narrative (Details) - USD ($) $ in Thousands			3 Months Ended		6 Months Ended		12 Months Ended
	Aug. 12, 2021	May 29, 2020	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Debt Instrument [Line Items]
Final fee			$ 540		$ 540		$ 627
Accrued liabilities and other			$ 500		$ 500		500
Term loan | Solar Term Loan
Debt Instrument [Line Items]
Aggregate principal amount		$ 40,000
Fixed interest rate (percent)		9.40%
Debt period payment, interest only period		36 months
Final fee		$ 1,000
Final fee as percentage of aggregate principal amount (percent)		2.50%
Effective interest rate during the period (percent)			6.90%	10.60%	6.60%	10.60%
Term loan | Solar Term Loan | Basis spread option
Debt Instrument [Line Items]
Basis spread on variable rate		0.33%
Term loan | SVB Term Loan
Debt Instrument [Line Items]
Aggregate principal amount	$ 35,000
Fixed interest rate (percent)	5.75%
Final fee	$ 700
Final fee as percentage of aggregate principal amount (percent)	2%
Unamortized debt issuance costs							1,300
Payments of prepayment penalty and lender fees							$ 500
Debt issuance costs	$ 100
Term loan | SVB Term Loan | Prepayment Penalty, 1-24 Months
Debt Instrument [Line Items]
Debt prepayment penalty percentage (percent)	1%
Term loan | SVB Term Loan | Prepayment Penalty, After 24 Months
Debt Instrument [Line Items]
Debt prepayment penalty percentage (percent)	0%
Term loan | SVB Term Loan | Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate	2.50%

Borrowings - Debt Maturity (Det

Borrowings - Debt Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Future principal and final fee payments
Remainder of 2022	$ 0
2023	7,292
2024	17,500
2025	10,908
2026	0
Total principal and final fee payments	$ 35,700	$ 35,700

Stock-Based Incentive Compens_3

Stock-Based Incentive Compensation Plans - Stock Option Activity (Details)	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Number of Shares
Outstanding, beginning of period (in shares) | shares	2,009,513
Exercised (in shares) | shares	(39,267)
Canceled and forfeited (in shares) | shares	(14,229)
Outstanding, end of period (in shares) | shares	1,956,017
Weighted-Average Exercise Price
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 8.73
Exercised (in dollars per share) | $ / shares	5.09
Canceled and forfeited (in dollars per share) | $ / shares	12.36
Outstanding, end of period (in dollars per share) | $ / shares	$ 10.22

Stock-Based Incentive Compens_4

Stock-Based Incentive Compensation Plans - Narrative (Details) $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended
	Jan. 31, 2022	May 31, 2020 purchase_period	Jun. 30, 2022 USD ($) shares	Jun. 30, 2021 USD ($) shares	Jun. 30, 2022 USD ($) shares	Jun. 30, 2021 USD ($) shares	Dec. 31, 2021 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, stock options | $			$ 700		$ 700
Stock options granted (in shares) | shares			0	0	0	0
Early exercise of stock options, share subject to repurchase (in shares) | shares			0		0		0
Issuance of common stock related to employee stock purchase plan (in shares) | shares					112,773	104,861
Issuance of common stock related to employee stock purchase plan | $			$ 1,199	$ 1,566	$ 1,600	$ 1,600
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, expected period for recognition (in years)					6 months
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, expected period for recognition (in years)					2 years 9 months 18 days
Unrecognized compensation cost | $			42,200		$ 42,200
Granted (in shares) | shares					1,130,467
Restricted Stock Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period					2 years
Restricted Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period					4 years
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, expected period for recognition (in years)					2 years 6 months
Unrecognized compensation cost | $			2,300		$ 2,300
Granted (in shares) | shares					155,596
2018 ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase price of common stock as a percent of fair market value (percent)					85%
Employee stock purchase program offering period interval (in months)		12 months			6 months
Number of purchase periods in offering interval | purchase_period		2
Accrued compensation and related expenses for employee payroll deductions | $			$ 200		$ 200		$ 300
2018 ESPP | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period	3 years

Stock-Based Incentive Compens_5

Stock-Based Incentive Compensation Plans - Valuation Assumptions for Stock Options (Details) - Performance Shares	6 Months Ended
	Jun. 30, 2022
Black-Scholes option-pricing model assumptions
Expected volatility of common stock, minimum (percent)	48.90%
Expected volatility of common stock, maximum (percent)	58.70%
Expected volatility of peer companies, minimum (percent)	24.20%
Expected volatility of peer companies, maximum (percent)	152.50%
Correlation coefficient of peer companies, minimum	(13.00%)
Correlation coefficient of peer companies, maximum	100%
Risk-free interest rate, minimum (percent)	0.40%
Risk-free interest rate, maximum (percent)	1.20%
Minimum
Black-Scholes option-pricing model assumptions
Dividend yield (percent)	0%
Maximum
Black-Scholes option-pricing model assumptions
Dividend yield (percent)	1%

Stock-Based Incentive Compens_6

Stock-Based Incentive Compensation Plans - Restricted Stock Units Activity and Performance-Based Restricted Stock Unit Activity (Details)	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding, beginning of period (in shares) | shares	1,566,522
Granted (in shares) | shares	1,130,467
Vested (in shares) | shares	(395,489)
Canceled and forfeited (in shares) | shares	(129,123)
Outstanding, end of period (in shares) | shares	2,172,377
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 25.17
Granted (in dollars per share) | $ / shares	21.30
Vested (in dollars per share) | $ / shares	24.88
Canceled and forfeited (in dollars per share) | $ / shares	23.81
Outstanding, end of period (in dollars per share) | $ / shares	$ 23.29
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding, beginning of period (in shares) | shares	0
Granted (in shares) | shares	155,596
Vested (in shares) | shares	0
Canceled and forfeited (in shares) | shares	0
Outstanding, end of period (in shares) | shares	155,596
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 0
Granted (in dollars per share) | $ / shares	19.50
Vested (in dollars per share) | $ / shares	0
Canceled and forfeited (in dollars per share) | $ / shares	0
Outstanding, end of period (in dollars per share) | $ / shares	$ 19.50

Stock-Based Incentive Compens_7

Stock-Based Incentive Compensation Plans - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 5,751	$ 4,257	$ 11,258	$ 8,287
Cost of goods sold
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	117	129	238	303
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	2,746	2,125	5,340	4,024
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	664	404	1,297	823
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,224	$ 1,599	$ 4,383	$ 3,137

Net Loss Per Share of Common _3

Net Loss Per Share of Common Stock - Computation of Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Share [Abstract]
Net loss	$ (18,513)	$ (17,410)	$ (13,981)	$ (12,242)	$ (35,923)	$ (26,223)
Weighted-average number of common shares used to compute basic net loss per share (in shares)	34,052,692		32,978,914		33,923,229	32,836,040
Weighted-average number of common shares used to compute diluted net loss per share (in shares)	34,052,692		32,978,914		33,923,229	32,836,040
Net loss per share, basic (in usd per share)	$ (0.54)		$ (0.42)		$ (1.06)	$ (0.80)
Net loss per share, diluted (in usd per share)	$ (0.54)		$ (0.42)		$ (1.06)	$ (0.80)

Net Loss Per Share of Common _4

Net Loss Per Share of Common Stock - Antidilutive Common Stock Equivalents Excluded from Computation of Earnings Per Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share (in shares)	4,306,204	4,021,396	4,306,204	4,021,396
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share (in shares)	1,956,017	2,147,895	1,956,017	2,147,895
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share (in shares)	2,172,377	1,719,364	2,172,377	1,719,364
Shares subject to repurchase
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share (in shares)	0	1,945	0	1,945
ESPP purchase rights
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share (in shares)	59,688	34,070	59,688	34,070
Common stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share (in shares)	118,122	118,122	118,122	118,122

Related Party Transaction (Deta

Related Party Transaction (Details) - SeaSpine - Joint development agreement - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Related Party Transaction [Line Items]
Reimbursement charges expensed	$ 0	$ 13,854	$ 6,225	$ 23,854
Term of product royalty sales period (in years)			10 years
Royalties	0		$ 0		$ 0
Outstanding liability to SeaSpine	$ 2,000		$ 2,000		$ 0