SI-BONE (SIBN) 10-Q 6 Aug 24 2024 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2024	Jul. 31, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2024
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		41,694,135
Entity Central Index Key	0001459839
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q2
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 25,577	$ 33,271
Short-term investments	125,950	132,748
Accounts receivable, net of allowance for credit losses of $1,291 and $1,118, respectively	24,796	21,953
Inventory	23,233	20,249
Prepaid expenses and other current assets	2,777	3,173
Total current assets	202,333	211,394
Property and equipment, net	19,108	16,000
Operating lease right-of-use assets	2,079	2,706
Other non-current assets	323	325
TOTAL ASSETS	223,843	230,425
Current liabilities:
Accounts payable	7,180	4,588
Accrued liabilities and other	13,496	17,452
Operating lease liabilities, current portion	1,384	1,416
Total current liabilities	22,060	23,456
Long-term borrowings	36,149	36,065
Operating lease liabilities, net of current portion	887	1,511
Other long-term liabilities	14	18
TOTAL LIABILITIES	59,110	61,050
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; 41,510,811 and 40,693,299 shares issued and outstanding, respectively	4	4
Additional paid-in capital	584,786	569,477
Accumulated other comprehensive income	227	335
Accumulated deficit	(420,284)	(400,441)
TOTAL STOCKHOLDERS’ EQUITY	164,733	169,375
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 223,843	$ 230,425

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 1,291	$ 1,118
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)	41,510,811	40,693,299
Common stock outstanding (in shares)	41,510,811	40,693,299

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Statement [Abstract]
Revenue	$ 39,969	$ 33,305	$ 77,836	$ 66,013
Cost of goods sold	8,393	6,318	16,395	12,242
Gross profit	31,576	26,987	61,441	53,771
Operating expenses:
Sales and marketing	28,970	27,492	58,357	54,805
Research and development	4,352	3,656	8,697	6,947
General and administrative	8,332	7,802	16,508	15,275
Total operating expenses	41,654	38,950	83,562	77,027
Loss from operations	(10,078)	(11,963)	(22,121)	(23,256)
Interest and other income (expense), net:
Interest income	2,015	1,582	4,128	2,515
Interest expense	(880)	(850)	(1,761)	(1,689)
Other income (expense)	4	25	(89)	99
Net loss	(8,939)	(11,206)	(19,843)	(22,331)
Other comprehensive income (loss):
Changes in foreign currency translation	(31)	3	(2)	(19)
Unrealized gain (loss) on marketable securities	(8)	(5)	(106)	85
Comprehensive loss	$ (8,978)	$ (11,208)	$ (19,951)	$ (22,265)
Net loss per share, basic (in usd per share)	$ (0.22)	$ (0.30)	$ (0.48)	$ (0.61)
Net loss per share, diluted (in usd per share)	$ (0.22)	$ (0.30)	$ (0.48)	$ (0.61)
Weighted-average number of common shares used to compute basic net loss per share (in shares)	41,317,627	37,864,185	41,126,009	36,399,309
Weighted-average number of common shares used to compute diluted net loss per share (in shares)	41,317,627	37,864,185	41,126,009	36,399,309

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, 2022		34,731,577
Stockholders' equity, beginning of period at Dec. 31, 2022	$ 98,302	$ 3	$ 455,172	$ 232	$ (357,105)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net of shares withheld (in shares)		120,266
Issuance of common stock upon exercise of stock options, net of shares withheld	520		520
Issuance of common stock upon vesting of restricted stock units (in shares)		254,320
Stock-based compensation	6,194		6,194
Foreign currency translation	(22)			(22)
Net unrealized gain (loss) on marketable securities	90			90
Net loss	(11,125)				(11,125)
Stockholders' equity, end of period (in shares) at Mar. 31, 2023		35,106,163
Stockholders' equity, end of period at Mar. 31, 2023	93,959	$ 3	461,886	300	(368,230)
Stockholders' equity, beginning of period (in shares) at Dec. 31, 2022		34,731,577
Stockholders' equity, beginning of period at Dec. 31, 2022	$ 98,302	$ 3	455,172	232	(357,105)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock related to employee stock purchase plan (in shares)	130,867
Issuance of common stock related to employee stock purchase plan	$ 1,500
Foreign currency translation	(19)
Net unrealized gain (loss) on marketable securities	85
Net loss	(22,331)
Stockholders' equity, end of period (in shares) at Jun. 30, 2023		40,087,765
Stockholders' equity, end of period at Jun. 30, 2023	177,407	$ 4	556,541	298	(379,436)
Stockholders' equity, beginning of period (in shares) at Mar. 31, 2023		35,106,163
Stockholders' equity, beginning of period at Mar. 31, 2023	93,959	$ 3	461,886	300	(368,230)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock from public offerings, net of underwriting discounts, commissions and offering costs (in shares)		4,068,497
Issuance of common stock from public offerings, net of underwriting discounts, commissions and offering costs	83,672	$ 1	83,671
Issuance of common stock upon exercise of stock options, net of shares withheld (in shares)		497,926
Issuance of common stock upon exercise of stock options, net of shares withheld	$ 3,515		3,515
Issuance of common stock related to employee stock purchase plan (in shares)	130,867	130,867
Issuance of common stock related to employee stock purchase plan	$ 1,471		1,471
Issuance of common stock upon vesting of restricted stock units (in shares)		261,709
Issuance of common stock upon exercise of warrant, net of shares withheld (in shares)		22,603
Stock-based compensation	5,998		5,998
Foreign currency translation	3			3
Net unrealized gain (loss) on marketable securities	(5)			(5)
Net loss	(11,206)				(11,206)
Stockholders' equity, end of period (in shares) at Jun. 30, 2023		40,087,765
Stockholders' equity, end of period at Jun. 30, 2023	$ 177,407	$ 4	556,541	298	(379,436)
Stockholders' equity, beginning of period (in shares) at Dec. 31, 2023	40,693,299	40,693,299
Stockholders' equity, beginning of period at Dec. 31, 2023	$ 169,375	$ 4	569,477	335	(400,441)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net of shares withheld (in shares)		29,892
Issuance of common stock upon exercise of stock options, net of shares withheld	105		105
Issuance of common stock upon vesting of restricted stock units (in shares)		355,571
Stock-based compensation	7,030		7,030
Foreign currency translation	29			29
Net unrealized gain (loss) on marketable securities	(98)			(98)
Net loss	(10,904)				(10,904)
Stockholders' equity, end of period (in shares) at Mar. 31, 2024		41,078,762
Stockholders' equity, end of period at Mar. 31, 2024	$ 165,537	$ 4	576,612	266	(411,345)
Stockholders' equity, beginning of period (in shares) at Dec. 31, 2023	40,693,299	40,693,299
Stockholders' equity, beginning of period at Dec. 31, 2023	$ 169,375	$ 4	569,477	335	(400,441)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net of shares withheld (in shares)	99,320
Issuance of common stock related to employee stock purchase plan (in shares)	114,636
Issuance of common stock related to employee stock purchase plan	$ 1,500
Foreign currency translation	(2)
Net unrealized gain (loss) on marketable securities	(106)
Net loss	$ (19,843)
Stockholders' equity, end of period (in shares) at Jun. 30, 2024	41,510,811	41,510,811
Stockholders' equity, end of period at Jun. 30, 2024	$ 164,733	$ 4	584,786	227	(420,284)
Stockholders' equity, beginning of period (in shares) at Mar. 31, 2024		41,078,762
Stockholders' equity, beginning of period at Mar. 31, 2024	165,537	$ 4	576,612	266	(411,345)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net of shares withheld (in shares)		69,428
Issuance of common stock upon exercise of stock options, net of shares withheld	$ 304		304
Issuance of common stock related to employee stock purchase plan (in shares)	114,636	114,636
Issuance of common stock related to employee stock purchase plan	$ 1,472		1,472
Issuance of common stock upon vesting of restricted stock units (in shares)		247,985
Stock-based compensation	6,398		6,398
Foreign currency translation	(31)			(31)
Net unrealized gain (loss) on marketable securities	(8)			(8)
Net loss	$ (8,939)				(8,939)
Stockholders' equity, end of period (in shares) at Jun. 30, 2024	41,510,811	41,510,811
Stockholders' equity, end of period at Jun. 30, 2024	$ 164,733	$ 4	$ 584,786	$ 227	$ (420,284)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Cash flows from operating activities
Net loss	$ (8,939)	$ (10,904)	$ (11,206)	$ (11,125)	$ (19,843)	$ (22,331)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation					13,428	12,192
Depreciation and amortization					2,081	2,322
Accounts receivable credit losses					240	103	$ 761
Amortization of discount and premium on marketable securities					(3,019)	(1,249)
Inventory reserve					366	159
Amortization of debt issuance costs					85	123
Loss on disposal of property and equipment					819	340
Changes in operating assets and liabilities:
Accounts receivable					(3,022)	88
Inventory					(3,314)	(3,452)
Prepaid expenses and other assets					399	262
Accounts payable					1,828	(7)
Accrued liabilities and other					(3,953)	(2,893)
Net cash used in operating activities					(13,905)	(14,343)
Cash flows from investing activities
Maturities of marketable securities					119,000	69,000
Purchases of marketable securities					(109,288)	(49,723)
Purchases of property and equipment					(5,195)	(5,293)
Net cash provided by investing activities					4,517	13,984
Cash flows from financing activities
Proceeds from public offering, net of discounts, commissions and offering costs					0	84,137
Proceeds from debt financing					0	36,000
Repayments of debt financing					0	(35,275)
Payments of debt issuance costs					0	(40)
Proceeds from issuance of common stock under employee stock purchase plan					1,472	1,471
Proceeds from the exercise of stock options					409	4,035
Net cash provided by financing activities					1,881	90,328
Effect of exchange rate changes on cash and cash equivalents					(187)	129
Net increase (decrease) in cash and cash equivalents					(7,694)	90,098
Cash and cash equivalents at
Beginning of period		$ 33,271		$ 20,717	33,271	20,717	20,717
End of period	$ 25,577		$ 110,815		25,577	110,815	$ 33,271
Supplemental disclosure of non-cash information
Unpaid purchases of property and equipment					1,293	510
Public offering costs included in accounts payable					$ 0	$ 465

The Company and Nature of Busin

The Company and Nature of Business	6 Months Ended
	Jun. 30, 2024
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 dedicated to solving musculoskeletal disorders of the sacropelvic anatomy. Leveraging its knowledge of pelvic anatomy and biomechanics, the Company has pioneered proprietary minimally invasive surgical implant systems to address sacroiliac joint dysfunction as well as address unmet clinical needs in pelvic fixation and management of pelvic fractures. The Company’s products include a series of patented titanium implants and the instruments used to implant them, as well as implantable bone products. Since launching its first generation iFuse in 2009, the Company has launched multiple titanium implant product lines, including iFuse-3D in 2017, iFuse-TORQ in 2021, iFuse Bedrock Granite in 2022 and iFuse INTRA, an implantable bone product, in January 2024.Within the United States, iFuse, iFuse-3D and iFuse-TORQ have clearances for applications across sacroiliac joint dysfunction and fusion, adult spinal deformity and degeneration, and pelvic trauma. In May 2023, the Company received a total of $83.7 million of net proceeds after deducting the underwriting discounts and commissions from the offering of 3,775,000 shares of the Company’s common stock and the exercise of underwriter's option to purchase from the Company an additional 566,250 shares of the Company's common stock, at a public offering price of $22.00 per share. Of these shares, 272,753 shares were offered by a selling stockholder and did not result in any proceeds to the Company.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2024
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, 2023 has been derived from the audited consolidated financial statements at that date but does not include all of the information required by U.S. 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, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024 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, 2023 contained in the Company’s Annual Report on Form 10-K filed with the SEC on February 27, 2024 (the “2023 Annual Report”). 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. Change in accounting estimate During the first quarter of 2024, the Company reassessed the useful life of its instrument trays based on a comprehensive evaluation of usage trends and its estimate on the average life of instruments before loss or damage that requires disposal. As a result of this review, the Company determined that extending the useful life of its instrument trays would more accurately reflect its anticipated future economic benefits. Effective January 1, 2024, the Company changed its estimates of the useful lives of instrument trays from three Significant Accounting Policies The Company’s significant accounting policies are disclosed in the 2023 Annual Report. There have been no material changes to these accounting policies. 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. The following table summarizes the Company's revenue by geography: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) United States $ 37,813 $ 31,215 $ 73,238 $ 61,665 International 2,156 2,090 4,598 4,348 $ 39,969 $ 33,305 $ 77,836 $ 66,013 Recent Accounting Pronouncements In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. ASU 2023-07 requires companies with a single reportable segment to provide all existing segment disclosures, as well as requires incremental segment information to be disclosed. The guidance is effective for fiscal years beginning after December 15, 2023 on a retrospective basis, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. The Company is currently evaluating the guidance to determine the impact on its disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures ("ASU 2023-09"). ASU 2023-09 requires public business entities to disclose additional information in specified categories with respect to the reconciliation of the effective tax rate to the statutory rate (the rate reconciliation) for federal, state, and foreign income taxes. It also requires greater detail about individual reconciling items in the rate reconciliation to the extent the impact of those items exceeds a specified threshold. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, and for interim periods for fiscal years beginning after December 15, 2025. The Company is currently evaluating the impacts of ASU 2023-09 on its disclosures.

Marketable Securities

Marketable Securities	6 Months Ended
	Jun. 30, 2024
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, 2024 Amortized Cost Unrealized Gains Unrealized Losses Aggregate Fair Value (in thousands) Money market funds $ 21,693 $ — $ — $ 21,693 Cash equivalents 21,693 — — 21,693 U.S. treasury securities 125,990 1 (41) 125,950 Short-term investments 125,990 1 (41) 125,950 Total marketable securities $ 147,683 $ 1 $ (41) $ 147,643 December 31, 2023 Amortized Cost Unrealized Gains Unrealized Losses Aggregate Fair Value (in thousands) Money market funds $ 23,331 $ — $ — $ 23,331 Cash equivalents 23,331 — — 23,331 U.S. treasury securities 129,695 67 — 129,762 U.S. agency bonds 2,988 — (2) 2,986 Short-term investments 132,683 67 (2) 132,748 Total marketable securities $ 156,014 $ 67 $ (2) $ 156,079 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 three and six months ended June 30, 2024 and 2023, 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, 2024 and December 31, 2023. 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, 2024, and was recorded in prepaid expenses and other current assets

Fair Value Measurement

Fair Value Measurement	6 Months Ended
	Jun. 30, 2024
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, 2024 Level 1 Level 2 Level 3 Total (in thousands) Marketable securities Money market funds $ 21,693 $ — $ — $ 21,693 U.S. treasury securities 125,950 — — 125,950 Total marketable securities $ 147,643 $ — $ — $ 147,643 December 31, 2023 Level 1 Level 2 Level 3 Total (in thousands) Marketable securities Money market funds $ 23,331 $ — $ — $ 23,331 U.S. treasury securities 129,762 — — 129,762 U.S. agency bonds — 2,986 — 2,986 Total marketable securities $ 153,093 $ 2,986 $ — $ 156,079

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Balance Sheet Components Inventory As of June 30, 2024, inventory consisted of finished goods of $21.2 million and work-in-progress and components of $2.0 million. As of December 31, 2023, inventory consisted of finished goods of $18.8 million and work-in-progress and components of $1.4 million. Property and Equipment, net: June 30, 2024 December 31, 2023 (in thousands) Instrument trays $ 19,830 $ 18,205 Machinery and equipment 3,189 3,067 Construction in progress 6,761 3,856 Computer and office equipment 2,354 1,856 Leasehold improvements 3,873 3,873 Furniture and fixtures 388 389 36,395 31,246 Less: Accumulated depreciation and amortization (17,287) (15,246) $ 19,108 $ 16,000 As of June 30, 2024, construction in progress pertains to the cost of individual components of an instrument tray used for surgical placement of the Company's products that have not yet been placed into service of $6.3 million and software costs of $0.5 million. As of December 31, 2023, construction in progress pertains to cost of individual components of an instrument tray used for surgical placement of the Company's products that have not yet been placed into service of $3.5 million and software costs of $0.4 million. Depreciation expense was $1.0 million and $1.2 million for the three months ended June 30, 2024 and 2023, respectively. Depreciation expense was $2.1 million and $2.3 million for the six months ended June 30, 2024 and 2023, respectively. Accrued Liabilities and Other : June 30, 2024 December 31, 2023 (in thousands) Accrued compensation and related expenses $ 8,893 $ 13,464 Accrued royalty 1,581 1,360 Accrued professional services 953 929 Others 2,069 1,699 $ 13,496 $ 17,452 Accounts Receivable and Allowance for Credit Losses: The movement in the allowance for credit losses was as follows: June 30, 2024 December 31, 2023 (in thousands) Balance at beginning of period $ 1,118 $ 400 Provision 240 761 Write-offs (67) (43) Balance at end of period $ 1,291 $ 1,118

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2024
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 July 2026 and a building used for research and development and warehouse space in Santa Clara, California which expires in October 2026. The Company also has a non-cancelable operating lease for its office building spaces in Gallarate, Italy which expires in August 2027. The Company also leases vehicles under operating lease arrangements for certain of its personnel in Europe which expire at various times throughout 2024 to 2026. Supplemental information related to lease expense and valuation of the lease assets and lease liabilit ies are as follows: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Operating lease expense $ 370 $ 390 $ 753 $ 783 Variable lease expense 146 124 281 201 Total lease expense $ 516 $ 514 $ 1,034 $ 984 Cash paid for amounts included in the measurement of operating lease liabilities $ 388 $ 439 $ 786 $ 836 Leased assets obtained in exchange for new operating lease liabilities $ — $ 103 $ — $ 124 June 30, 2024 December 31, 2023 Weighted average remaining lease term (in years) 1.82 2.20 Weighted average discount rate 5.92% 5.87% Future minimum lease payments under non-cancelable operating leases as of June 30, 2024 was as follows: Year Ending December 31, (in thousands) Remainder of 2024 $ 771 2025 1,053 2026 563 2027 7 2028 — Thereafter — Total operating lease payments 2,394 Less: imputed interest (123) Total operating lease liabilities $ 2,271 As of June 30, 2024, 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 $0.4 million as of June 30, 2024 and December 31, 2023. 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, 2024
Debt Disclosure [Abstract]
Borrowings	Borrowings Term Loan The following table summarizes the outstanding borrowings from the term loan as of periods presented: June 30, 2024 December 31, 2023 (in thousands) Principal outstanding and final fee $ 36,720 $ 36,720 Less: Unamortized debt issuance costs (71) (81) Unaccreted value of final fee (500) (574) Outstanding debt, net of debt issuance costs and unaccreted value of final fee $ 36,149 $ 36,065 Classified as: Long-term borrowings $ 36,149 $ 36,065 The outstanding debt is related to a term loan pursuant to the Loan and Security Agreement dated August 12, 2021 entered into by the Company with Silicon Valley Bank (“SVB” or the “Lender”) (the “Original Loan Agreement”). Pursuant to the Original Loan Agreement, SVB provided a term loan in an aggregate principal amount of $35.0 million to the Company (the “Original Term Loan”). On January 6, 2023, the Company entered into a First Amendment to Loan and Security Agreement (the “First Amendment”) with SVB, which amended the Company's Original Term Loan pursuant to which the Company received a new term loan facility in an aggregate principal amount of $36.0 million (the “Original Loan Agreement” with the Amendment, collectively the “Amended Loan Agreement”). Upon entry into the Amended Loan Agreement, the Company borrowed $36.0 million pursuant to a term loan (the "Term Loan"), which was substantially used to repay in full the $35.0 million term loan outstanding under the Original Loan Agreement and secured a revolving credit facility in an aggregate principal amount of up to $15.0 million (the “Revolving Line”). The Amended Loan Agreement also includes an uncommitted accordion term loan in an aggregate principal amount of up to $15.0 million, which accordion may be approved by the Lender solely in its discretion, upon the Company’s request. The Term Loan matures on December 1, 2027 (the “Term Loan Maturity Date”). Interest on the Term Loan will be payable monthly at a floating annual rate set at the greater of (i) the prime rate as published in the Wall Street Journal plus 0.5% or (ii) 6.75%. Commencing on July 1, 2025, the Company will be required to make monthly principal Term Loan amortization payments. A final fee payment of 2% of the original principal amount of the Term Loan is due upon the earlier of the Term Loan Maturity Date, termination of the Amended Loan Agreement, acceleration by the Lender following an event of default, or prepayment of the Term Loan. The Company may elect to prepay the Term Loan in whole prior to the Term Loan Maturity Date subject to a prepayment fee equal to 2% of the principal amount of the Term Loan prepaid at such time. No prepayment fee would be due if the Term Loan is refinanced by the Lender. Pursuant to the terms of the Amended Loan Agreement, revolving loans may be borrowed, repaid and reborrowed until the maturity date, which will be July 6, 2025 (the “Revolving Line Maturity Date”). Borrowings under the Revolving Line are based on 80% of eligible domestic accounts receivable borrowing base. Interest on the outstanding balance of the Revolving Line will be payable monthly at a floating annual rate set at the greater of the prime rate as published in the Wall Street Journal or 6.25%. Interest on borrowings is due monthly and any principal balance is due on the Revolving Line Maturity Date, provided that when Revolving Line Advances are outstanding, in the event the Company does not maintain an adjusted quick ratio of at least 1.5 to 1.0, then falling below such threshold will allow the Lender to apply accounts receivable collections to outstanding Revolving Line borrowings. The Company will pay a total commitment fee of $187,500 on account of the Revolving Line payable in installments, but fully earned at close. The Company will also be required to pay a fee of $150,000 if it terminates the Amended Loan Agreement or Revolving Line prior to Revolving Line Maturity Date, or if the Lender terminates the Loan Agreement or the Revolving Line following an event of default. No termination fee would be due if the Revolving Line is replaced with a new facility with the Lender. On March 14, 2023, all of SVB’s assets and liabilities, including all of SVB’s rights as the lender pursuant to the Amended Loan Agreement, were assigned to Silicon Valley Bridge Bank. On March 27, 2023, all of Silicon Valley Bridge Bank’s assets and liabilities were assigned and assumed by First-Citizens Bank & Trust Company (“First-Citizens”). On January 25, 2024, the Company entered into a Second Amendment to Loan and Security Agreement with SVB which amends the Company's Amended Loan Agreement (the “Second Amendment” and together with the Amended Loan Agreement, the “Second Amended Loan Agreement”). The Second Amendment revised certain provisions related to financial covenants and the periods in which the covenants apply. No amounts were outstanding under the Revolver as of June 30, 2024. The Company accounted for the Second Amended Loan Agreement as a debt modification. Accordingly, the remaining unamortized debt issuance costs related to the Original Loan Agreement together with any lender fees incurred in connection with the entry of the Second Amended Loan Agreement are amortized to interest expense using the straight-line method over the new term of the loan through December 2027. As of June 30, 2024, the Company was in compliance with all other debt covenants, provided, however, that in order to access future credit advances under the Revolving Line, it will be required to redirect certain customer payments and transfer certain cash management account balances, in each case, back to First-Citizens. As of June 30, 2024, the Company had cash management accounts with a financial institution other than First-Citizens and instructed its customers to direct payments to the Company to these separate operating accounts. Until such customer payments are directed back to certain First-Citizens cash collateral accounts, and certain balances and funds are moved back to the First-Citizens cash collateral accounts and other accounts held at First-Citizens, the Company will be unable to obtain credit advances under the Revolving Line. The effective interest rate related to the First-Citizens Term Loan for the three and six months ended June 30, 2024 was 9.3%. The effective interest rate related to the First-Citizens Term Loan for the three and six months ended June 30, 2023 was 8.9% and 8.8%, respectively. The table below summarizes the future principal and final fee payments under the Fist-Citizens Term Loan as of June 30, 2024: Year ending December 31, (in thousands) Remainder of 2024 $ — 2025 8,400 2026 14,400 2027 13,920 2028 — Total principal and final fee payments $ 36,720 The Second Amended 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, 2024, the Company was in compliance with all debt covenants.

Stock-Based Incentive Compensat

Stock-Based Incentive Compensation Plans	6 Months Ended
	Jun. 30, 2024
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, 2024: Number of Weighted- Weighted-Average Contractual Remaining Life (Years) Aggregate Intrinsic Value (in thousands) Outstanding as of December 31, 2023 1,188,708 $ 10.14 3.51 $ 13,197 Exercised (99,320) $ 4.11 Canceled and forfeited (1,111) $ 18.47 Outstanding as of June 30, 2024 1,088,277 $ 10.68 3.21 $ 5,648 Options vested and exercisable, June 30, 2024 1,088,277 $ 10.68 3.21 $ 5,648 Options vested and expected to vest, June 30, 2024 1,088,277 $ 10.68 3.21 $ 5,648 As of June 30, 2024, there is no unrecognized compensation cost related to stock options. There were no stock options granted during the three and six months ended June 30, 2024 and 2023. Restricted Stock Units (“RSUs”) 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 one ecognized compensation cost related to the RSUs was $36.9 million, which is expected to be recognized over a period of approximately 2.6 years. 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 PSUs vest over a three-year performance period. 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 summarizes the assumptions used to estimate the grant date fair value of the PSUs granted: Six Months Ended June 30, 2024 2023 Expected volatility of common stock 47.0% to 59.0% 58.0% to 73.0% Expected volatility of peer companies 29.0% to 97.0% 33.0% to 141.0% Correlation coefficient of peer companies (0.01) to 1.00 (0.15) to 1.00 Risk-free interest rate 4.1% to 4.7% 3.9% to 5.0% Dividend yield 0.6% to 4.7% —% to 1.3% As of June 30, 2024, the unrecognized compensation cost related to the PSUs was $5.9 million, which is expected to be recognized over a period of approximately 2.2 years. The table below summarizes RSU and PSU activity for the six months ended June 30, 2024: 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, 2023 1,899,790 $19.93 385,122 $14.74 Granted 1,041,308 18.35 319,858 18.48 Vested (509,117) 21.19 (94,439) 16.27 Canceled and forfeited (44,048) 20.10 — — Outstanding as of June 30, 2024 2,387,933 18.97 610,541 16.47 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. 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 114,636 and 130,867 shares under the ESPP, representing $1.5 million in employee contributions for each of the three and six months ended June 30, 2024 and 2023. As of June 30, 2024 and December 31, 2023, total accumulated ESPP related employee payroll deductions amounted to $0.2 million and $0.4 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 2024 2023 2024 2023 (in thousands) Cost of goods sold $ 257 $ 161 $ 491 $ 298 Sales and marketing 2,709 2,702 5,930 5,612 Research and development 823 748 1,643 1,500 General and administrative 2,609 2,387 5,364 4,782 $ 6,398 $ 5,998 $ 13,428 $ 12,192 Warrants The table below summarizes common stock warrants activity for the six months ended June 30, 2024: Date Outstanding Balance at December 31, 2023 Price per Share Warrants Issued Warrant Exercised Warrant Expired Outstanding Balance at June 30, 2024 Issuance Expiration 3/1/2017 3/1/2027 1,388 $ 5.94 — — — 1,388 11/26/2014 11/26/2024 6,680 $ 16.47 — — — 6,680 10/20/2015 10/20/2025 41,650 $ 16.47 — — — 41,650 11/9/2015 11/9/2025 25,709 $ 16.47 — — 25,709 12/22/2016 12/22/2026 9,712 $ 10.03 — — — 9,712 85,139 — — — 85,139

Net Loss Per Share of Common St

Net Loss Per Share of Common Stock	6 Months Ended
	Jun. 30, 2024
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, 2024 2023 2024 2023 (in thousands, except share and per share data) Net loss $ (8,939) $ (11,206) $ (19,843) $ (22,331) Weighted-average shares used to compute basic and diluted net loss per share 41,317,627 37,864,185 41,126,009 36,399,309 Net loss per share, basic and diluted $ (0.22) $ (0.30) $ (0.48) $ (0.61) Because the Company has reported a net loss in all periods presented, outstanding stock options, restricted stock units, 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, 2024 2023 2024 2023 Stock options 1,088,277 1,269,147 1,088,277 1,269,147 Restricted stock units 2,998,474 2,320,750 2,998,474 2,320,750 ESPP purchase rights 63,987 38,727 63,987 38,727 Common stock warrants 85,139 85,139 85,139 85,139 4,235,877 3,713,763 4,235,877 3,713,763

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2024
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions On February 24, 2020, the Company entered into a joint development agreement (the “Development Agreement”) with SeaSpine Orthopedics Corporation (“SeaSpine”), which merged with Orthofix Medical, Inc. ("Orthofix"), to develop a next generation device for sacropelvic fixation. On April 27, 2021, the Company and SeaSpine entered into that certain Addendum No.1 to the Development Agreement to extend certain obligations as described under the Development Agreement to a consultant of the Company. Mr. Keith C. Valentine, formerly a member of the Company’s Board of Directors from August 2015 through June 2024, served as the President, Chief Executive Officer and a member of the board of directors of SeaSpine until its merger with Orthofix in January 2023, and subsequently as the President, Chief Executive Officer and a member of the board of directors of Orthofix until his resignation in October 2023. Subsequent to October 4, 2023, SeaSpine is no longer a related party 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 and six months ended June 30, 2023, the Company did not incur any reimbursement charges from Seaspine. 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 $0.1 million royalty for the three and six months ended June 30, 2023 .

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes In 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, 2024 and 2023. 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, 2024

Subsequent Event

Subsequent Event	6 Months Ended
	Jun. 30, 2024
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event On July 18, 2024, the Company and BIXBY SPE FINANCE 11, LLC (“Landlord”) entered into the Second Amendment (the “Second Lease Amendment”) to the Office Lease Agreement (the “Original Lease”) dated as of February 2, 2018, as amended by that certain First Amendment to Lease (the “First Amendment”) dated as of April 16, 2018 and as further supplemented by that certain Telecommunications License Agreement dated as of October 23, 2019 (collectively, as amended, the “Lease”). The Lease is for 21,848 square feet of office space located at 471 El Camino Real, Santa Clara, California, the Company’s corporate headquarters. Pursuant to the Second Lease Amendment, the Company and Landlord agreed to extend the term of the Lease for an additional period of fourteen months commencing on June 1, 2025 (the “Extension Date”), and expiring July 31, 2026 (the “Expiration Date”) with the base rent in the amount of $43,696 per month. The Company shall not be required to pay monthly base rent for the first three months from and after the Extension Date. Pursuant to the Second Lease Amendment, the Company agreed to continue to pay its share of operating expenses and taxes through the Expiration Date. The Second Lease Amendment terminates the 5-year extension option contained in the Original Lease.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Pay vs Performance Disclosure
Net loss	$ (8,939)	$ (10,904)	$ (11,206)	$ (11,125)	$ (19,843)	$ (22,331)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Jun. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2024
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, 2023 has been derived from the audited consolidated financial statements at that date but does not include all of the information required by U.S. 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, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024 or for any other interim period or for any other future year.
Use of Estimates and Change in accounting estimate	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. Change in accounting estimate three
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 .
Recent Accounting Pronouncements	Recent Accounting Pronouncements In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. ASU 2023-07 requires companies with a single reportable segment to provide all existing segment disclosures, as well as requires incremental segment information to be disclosed. The guidance is effective for fiscal years beginning after December 15, 2023 on a retrospective basis, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. The Company is currently evaluating the guidance to determine the impact on its disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures ("ASU 2023-09"). ASU 2023-09 requires public business entities to disclose additional information in specified categories with respect to the reconciliation of the effective tax rate to the statutory rate (the rate reconciliation) for federal, state, and foreign income taxes. It also requires greater detail about individual reconciling items in the rate reconciliation to the extent the impact of those items exceeds a specified threshold. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, and for interim periods for fiscal years beginning after December 15, 2025. The Company is currently evaluating the impacts of ASU 2023-09 on its disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Schedule of Revenue by Geography	The following table summarizes the Company's revenue by geography: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) United States $ 37,813 $ 31,215 $ 73,238 $ 61,665 International 2,156 2,090 4,598 4,348 $ 39,969 $ 33,305 $ 77,836 $ 66,013

Marketable Securities (Tables)

Marketable Securities (Tables)	6 Months Ended
	Jun. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Schedule of Marketable Securities	The table below summarizes the marketable securities: June 30, 2024 Amortized Cost Unrealized Gains Unrealized Losses Aggregate Fair Value (in thousands) Money market funds $ 21,693 $ — $ — $ 21,693 Cash equivalents 21,693 — — 21,693 U.S. treasury securities 125,990 1 (41) 125,950 Short-term investments 125,990 1 (41) 125,950 Total marketable securities $ 147,683 $ 1 $ (41) $ 147,643 December 31, 2023 Amortized Cost Unrealized Gains Unrealized Losses Aggregate Fair Value (in thousands) Money market funds $ 23,331 $ — $ — $ 23,331 Cash equivalents 23,331 — — 23,331 U.S. treasury securities 129,695 67 — 129,762 U.S. agency bonds 2,988 — (2) 2,986 Short-term investments 132,683 67 (2) 132,748 Total marketable securities $ 156,014 $ 67 $ (2) $ 156,079

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	6 Months Ended
	Jun. 30, 2024
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, 2024 Level 1 Level 2 Level 3 Total (in thousands) Marketable securities Money market funds $ 21,693 $ — $ — $ 21,693 U.S. treasury securities 125,950 — — 125,950 Total marketable securities $ 147,643 $ — $ — $ 147,643 December 31, 2023 Level 1 Level 2 Level 3 Total (in thousands) Marketable securities Money market funds $ 23,331 $ — $ — $ 23,331 U.S. treasury securities 129,762 — — 129,762 U.S. agency bonds — 2,986 — 2,986 Total marketable securities $ 153,093 $ 2,986 $ — $ 156,079

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Property and Equipment, Net	Property and Equipment, net: June 30, 2024 December 31, 2023 (in thousands) Instrument trays $ 19,830 $ 18,205 Machinery and equipment 3,189 3,067 Construction in progress 6,761 3,856 Computer and office equipment 2,354 1,856 Leasehold improvements 3,873 3,873 Furniture and fixtures 388 389 36,395 31,246 Less: Accumulated depreciation and amortization (17,287) (15,246) $ 19,108 $ 16,000
Schedule of Accrued Liabilities and Other	Accrued Liabilities and Other : June 30, 2024 December 31, 2023 (in thousands) Accrued compensation and related expenses $ 8,893 $ 13,464 Accrued royalty 1,581 1,360 Accrued professional services 953 929 Others 2,069 1,699 $ 13,496 $ 17,452
Schedule of Accounts Receivable and Allowance for Credit Losses	The movement in the allowance for credit losses was as follows: June 30, 2024 December 31, 2023 (in thousands) Balance at beginning of period $ 1,118 $ 400 Provision 240 761 Write-offs (67) (43) Balance at end of period $ 1,291 $ 1,118

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Summary of 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 June 30, Six Months Ended June 30, 2024 2023 2024 2023 Operating lease expense $ 370 $ 390 $ 753 $ 783 Variable lease expense 146 124 281 201 Total lease expense $ 516 $ 514 $ 1,034 $ 984 Cash paid for amounts included in the measurement of operating lease liabilities $ 388 $ 439 $ 786 $ 836 Leased assets obtained in exchange for new operating lease liabilities $ — $ 103 $ — $ 124 June 30, 2024 December 31, 2023 Weighted average remaining lease term (in years) 1.82 2.20 Weighted average discount rate 5.92% 5.87%
Schedule of Future Minimum Lease Payments Under Non-Cancelable Operating Leases	Future minimum lease payments under non-cancelable operating leases as of June 30, 2024 was as follows: Year Ending December 31, (in thousands) Remainder of 2024 $ 771 2025 1,053 2026 563 2027 7 2028 — Thereafter — Total operating lease payments 2,394 Less: imputed interest (123) Total operating lease liabilities $ 2,271

Borrowings (Tables)

Borrowings (Tables)	6 Months Ended
	Jun. 30, 2024
Debt Disclosure [Abstract]
Schedule of Outstanding Borrowings	The following table summarizes the outstanding borrowings from the term loan as of periods presented: June 30, 2024 December 31, 2023 (in thousands) Principal outstanding and final fee $ 36,720 $ 36,720 Less: Unamortized debt issuance costs (71) (81) Unaccreted value of final fee (500) (574) Outstanding debt, net of debt issuance costs and unaccreted value of final fee $ 36,149 $ 36,065 Classified as: Long-term borrowings $ 36,149 $ 36,065
Schedule of Future Principal and Final Fee Payments	The table below summarizes the future principal and final fee payments under the Fist-Citizens Term Loan as of June 30, 2024: Year ending December 31, (in thousands) Remainder of 2024 $ — 2025 8,400 2026 14,400 2027 13,920 2028 — Total principal and final fee payments $ 36,720

Stock-Based Incentive Compens_2

Stock-Based Incentive Compensation Plans (Tables)	6 Months Ended
	Jun. 30, 2024
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, 2024: Number of Weighted- Weighted-Average Contractual Remaining Life (Years) Aggregate Intrinsic Value (in thousands) Outstanding as of December 31, 2023 1,188,708 $ 10.14 3.51 $ 13,197 Exercised (99,320) $ 4.11 Canceled and forfeited (1,111) $ 18.47 Outstanding as of June 30, 2024 1,088,277 $ 10.68 3.21 $ 5,648 Options vested and exercisable, June 30, 2024 1,088,277 $ 10.68 3.21 $ 5,648 Options vested and expected to vest, June 30, 2024 1,088,277 $ 10.68 3.21 $ 5,648
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, 2024 2023 Expected volatility of common stock 47.0% to 59.0% 58.0% to 73.0% Expected volatility of peer companies 29.0% to 97.0% 33.0% to 141.0% Correlation coefficient of peer companies (0.01) to 1.00 (0.15) to 1.00 Risk-free interest rate 4.1% to 4.7% 3.9% to 5.0% Dividend yield 0.6% to 4.7% —% to 1.3%
Schedule of Restricted Stock Unit Activity	The table below summarizes RSU and PSU activity for the six months ended June 30, 2024: 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, 2023 1,899,790 $19.93 385,122 $14.74 Granted 1,041,308 18.35 319,858 18.48 Vested (509,117) 21.19 (94,439) 16.27 Canceled and forfeited (44,048) 20.10 — — Outstanding as of June 30, 2024 2,387,933 18.97 610,541 16.47
Schedule of Performance-based Restricted Stock Unit Activity Arrangement	The table below summarizes RSU and PSU activity for the six months ended June 30, 2024: 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, 2023 1,899,790 $19.93 385,122 $14.74 Granted 1,041,308 18.35 319,858 18.48 Vested (509,117) 21.19 (94,439) 16.27 Canceled and forfeited (44,048) 20.10 — — Outstanding as of June 30, 2024 2,387,933 18.97 610,541 16.47
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 2024 2023 2024 2023 (in thousands) Cost of goods sold $ 257 $ 161 $ 491 $ 298 Sales and marketing 2,709 2,702 5,930 5,612 Research and development 823 748 1,643 1,500 General and administrative 2,609 2,387 5,364 4,782 $ 6,398 $ 5,998 $ 13,428 $ 12,192
Schedule of Warrants Issued and Outstanding	The table below summarizes common stock warrants activity for the six months ended June 30, 2024: Date Outstanding Balance at December 31, 2023 Price per Share Warrants Issued Warrant Exercised Warrant Expired Outstanding Balance at June 30, 2024 Issuance Expiration 3/1/2017 3/1/2027 1,388 $ 5.94 — — — 1,388 11/26/2014 11/26/2024 6,680 $ 16.47 — — — 6,680 10/20/2015 10/20/2025 41,650 $ 16.47 — — — 41,650 11/9/2015 11/9/2025 25,709 $ 16.47 — — 25,709 12/22/2016 12/22/2026 9,712 $ 10.03 — — — 9,712 85,139 — — — 85,139

Net Loss Per Share of Common _2

Net Loss Per Share of Common Stock (Tables)	6 Months Ended
	Jun. 30, 2024
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, 2024 2023 2024 2023 (in thousands, except share and per share data) Net loss $ (8,939) $ (11,206) $ (19,843) $ (22,331) Weighted-average shares used to compute basic and diluted net loss per share 41,317,627 37,864,185 41,126,009 36,399,309 Net loss per share, basic and diluted $ (0.22) $ (0.30) $ (0.48) $ (0.61)
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, 2024 2023 2024 2023 Stock options 1,088,277 1,269,147 1,088,277 1,269,147 Restricted stock units 2,998,474 2,320,750 2,998,474 2,320,750 ESPP purchase rights 63,987 38,727 63,987 38,727 Common stock warrants 85,139 85,139 85,139 85,139 4,235,877 3,713,763 4,235,877 3,713,763

The Company and Nature of Bus_2

The Company and Nature of Business (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended				6 Months Ended
	May 31, 2023	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Subsidiary, Sale of Stock [Line Items]
Proceeds from public offering, net of discounts, commissions and offering costs						$ 0	$ 84,137
Additional shares purchased after exercise of option (in shares)						99,320
Common Stock
Subsidiary, Sale of Stock [Line Items]
Proceeds from public offering, net of discounts, commissions and offering costs	$ 83,700
Issuance of common stock from public offerings, net of underwriting discounts, commissions and offering costs (in shares)	3,775,000			4,068,497
Additional shares purchased after exercise of option (in shares)	566,250	69,428	29,892	497,926	120,266
Public offering price (in dollars per share)	$ 22
Number of shares offered by a selling stockholder (in shares)	272,753

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2024 USD ($) activity $ / shares	Mar. 31, 2024 USD ($)	Jun. 30, 2023 USD ($) $ / shares	Mar. 31, 2023 USD ($)	Jun. 30, 2024 USD ($) activity $ / shares	Jun. 30, 2023 USD ($) $ / shares	Jan. 01, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Depreciation expense, decrease | $	$ (1,000)		$ (1,200)		$ (2,100)	$ (2,300)
Decrease in net loss | $	$ (8,939)	$ (10,904)	$ (11,206)	$ (11,125)	$ (19,843)	$ (22,331)
Net loss per share, basic (in usd per share) | $ / shares	$ (0.22)		$ (0.30)		$ (0.48)	$ (0.61)
Net loss per share, diluted (in usd per share) | $ / shares	$ (0.22)		$ (0.30)		$ (0.48)	$ (0.61)
Number of business activities | activity	1				1
Service life
Property, Plant and Equipment [Line Items]
Depreciation expense, decrease | $	$ 500				$ 1,000
Decrease in net loss | $	$ 500				$ 1,000
Net loss per share, basic (in usd per share) | $ / shares	$ 0.01				$ 0.03
Net loss per share, diluted (in usd per share) | $ / shares	$ 0.01				$ 0.03
Instrument trays
Property, Plant and Equipment [Line Items]
Estimated useful life							5 years	3 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Revenue by Geography (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Revenue	$ 39,969	$ 33,305	$ 77,836	$ 66,013
United States
Disaggregation of Revenue [Line Items]
Revenue	37,813	31,215	73,238	61,665
International
Disaggregation of Revenue [Line Items]
Revenue	$ 2,156	$ 2,090	$ 4,598	$ 4,348

Marketable Securities - Schedul

Marketable Securities - Schedule of Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Cash equivalents
Carrying value	$ 21,693	$ 23,331
Short-term investments
Amortized Cost	125,990	132,683
Unrealized Gains	1	67
Unrealized Losses	(41)	(2)
Aggregate Fair Value	125,950	132,748
Total marketable securities, Amortized Cost	147,683	156,014
Total marketable securities, Aggregate Fair Value	147,643	156,079
Money market funds
Cash equivalents
Carrying value	21,693	23,331
U.S. treasury securities
Short-term investments
Amortized Cost	125,990	129,695
Unrealized Gains	1	67
Unrealized Losses	(41)	0
Aggregate Fair Value	$ 125,950	129,762
U.S. agency bonds
Short-term investments
Amortized Cost		2,988
Unrealized Gains		0
Unrealized Losses		(2)
Aggregate Fair Value		$ 2,986

Marketable Securities - Narrati

Marketable Securities - Narrative (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Credit losses on investments	$ 0	$ 0
Accrued interest receivable	$ 300,000
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Prepaid expenses and other current assets
Accrued interest writeoff	$ 0	$ 0

Fair Value Measurement (Details

Fair Value Measurement (Details) - Recurring - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Marketable securities
Marketable securities	$ 147,643	$ 156,079
Money market funds
Marketable securities
Marketable securities	21,693	23,331
U.S. treasury securities
Marketable securities
Marketable securities	125,950	129,762
U.S. agency bonds
Marketable securities
Marketable securities		2,986
Level 1
Marketable securities
Marketable securities	147,643	153,093
Level 1 | Money market funds
Marketable securities
Marketable securities	21,693	23,331
Level 1 | U.S. treasury securities
Marketable securities
Marketable securities	125,950	129,762
Level 1 | U.S. agency bonds
Marketable securities
Marketable securities		0
Level 2
Marketable securities
Marketable securities	0	2,986
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 | U.S. agency bonds
Marketable securities
Marketable securities		2,986
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 | U.S. agency bonds
Marketable securities
Marketable securities		$ 0

Balance Sheet Components - Narr

Balance Sheet Components - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Inventory, finished goods, gross	$ 21,200		$ 21,200		$ 18,800
Inventory, work in process, gross	2,000		2,000		1,400
Property and equipment, gross	36,395		36,395		31,246
Depreciation expense	1,000	$ 1,200	2,100	$ 2,300
Construction in progress, surgical placement instrument set
Property, Plant and Equipment [Line Items]
Property and equipment, gross	6,300		6,300		3,500
Construction in progress, software costs
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 500		$ 500		$ 400

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Property and Equipment, Net
Property and equipment, gross	$ 36,395	$ 31,246
Less: Accumulated depreciation and amortization	(17,287)	(15,246)
Property and equipment, net	19,108	16,000
Instrument trays
Property and Equipment, Net
Property and equipment, gross	19,830	18,205
Machinery and equipment
Property and Equipment, Net
Property and equipment, gross	3,189	3,067
Construction in progress
Property and Equipment, Net
Property and equipment, gross	6,761	3,856
Computer and office equipment
Property and Equipment, Net
Property and equipment, gross	2,354	1,856
Leasehold improvements
Property and Equipment, Net
Property and equipment, gross	3,873	3,873
Furniture and fixtures
Property and Equipment, Net
Property and equipment, gross	$ 388	$ 389

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Liabilities and Other (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Accrued Liabilities and Other
Accrued compensation and related expenses	$ 8,893	$ 13,464
Accrued royalty	1,581	1,360
Accrued professional services	953	929
Others	2,069	1,699
Accrued liabilities and other	$ 13,496	$ 17,452

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, 2024	Jun. 30, 2023	Dec. 31, 2023
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 1,118	$ 400	$ 400
Provision	240	$ 103	761
Write-offs	(67)		(43)
Balance at end of period	$ 1,291		$ 1,118

Commitment and Contingencies -

Commitment and Contingencies - Supplemental Information Related to Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Operating lease expense	$ 370	$ 390	$ 753	$ 783
Variable lease expense	146	124	281	201
Total lease expense	516	514	1,034	984
Cash paid for amounts included in the measurement of operating lease liabilities	388	439	786	836
Leased assets obtained in exchange for new operating lease liabilities	$ 0	$ 103	$ 0	$ 124
Weighted average remaining lease term (in years)	1 year 9 months 25 days		1 year 9 months 25 days		2 years 2 months 12 days
Weighted average discount rate	5.92%		5.92%		5.87%

Commitments and Contingencies -

Commitments and Contingencies - Aggregate Future Minimum Lease Payments (Details) $ in Thousands	Jun. 30, 2024 USD ($)
Aggregate Future Minimum Lease Payments
Remainder of 2024	$ 771
2025	1,053
2026	563
2027	7
2028	0
Thereafter	0
Total operating lease payments	2,394
Less: imputed interest	(123)
Total operating lease liabilities	$ 2,271

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details) - USD ($)	6 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Other Commitments [Line Items]
Operating lease liabilities not commenced	$ 0
Purchase commitments related to inventory management and training materials	400,000	$ 400,000
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, 2024	Dec. 31, 2023
Debt Disclosure [Abstract]
Principal outstanding and final fee	$ 36,720	$ 36,720
Less: Unamortized debt issuance costs	(71)	(81)
Unaccreted value of final fee	(500)	(574)
Outstanding debt, net of debt issuance costs and unaccreted value of final fee	36,149	36,065
Long-term borrowings	$ 36,149	$ 36,065

Borrowings - Narrative (Details

Borrowings - Narrative (Details)		3 Months Ended		6 Months Ended
	Jan. 06, 2023 USD ($) quick_ratio	Jun. 30, 2024 USD ($)	Jun. 30, 2023	Jun. 30, 2024 USD ($)	Jun. 30, 2023	Aug. 12, 2021 USD ($)
SVB Term Loan | Term loan
Debt Instrument [Line Items]
Aggregate principal amount						$ 35,000,000
Proceeds from (repayments of) term loan	$ (35,000,000)
First-Citizens Amended Term Loan | Term loan
Debt Instrument [Line Items]
Proceeds from (repayments of) term loan	$ 36,000,000
Final fee as percentage of aggregate principal amount	2%
First-Citizens Amended Term Loan | Term loan | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
First-Citizens Amended Term Loan | Term loan | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	6.75%
First-Citizens Amended Term Loan | Term loan | Revolving credit facility
Debt Instrument [Line Items]
Accordion feature, increase limit	$ 15,000,000
Accounts receivable borrowing base (percent)	80%
Fixed interest rate	6.25%
Adjusted quick ratio threshold | quick_ratio	1.5
First-Citizens Amended Term Loan | Line of credit | Revolving credit facility
Debt Instrument [Line Items]
Revolving credit facility, aggregate principal amount	$ 15,000,000
Total commitment fee, amount	187,500
Contingent fee, amount	$ 150,000
Line of credit outstanding		$ 0		$ 0
First-Citizens Term Loan | Term loan
Debt Instrument [Line Items]
Effective interest rate during the period		9.30%	8.90%	9.30%	8.80%

Borrowings - Debt Maturity (Det

Borrowings - Debt Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Future principal and final fee payments
Remainder of 2024	$ 0
2025	8,400
2026	14,400
2027	13,920
2028	0
Total principal and final fee payments	$ 36,720	$ 36,720

Stock-Based Incentive Compens_3

Stock-Based Incentive Compensation Plans - Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares
Number of Shares
Outstanding, beginning of period (in shares) | shares	1,188,708
Exercised (in shares) | shares	(99,320)
Canceled and forfeited (in shares) | shares	(1,111)
Outstanding, end of period (in shares) | shares	1,088,277	1,188,708
Options vested and exercisable (in shares) | shares	1,088,277
Options vested and expected to vest (in shares) | shares	1,088,277
Weighted- Average Exercise Price
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 10.14
Exercised (in dollars per share) | $ / shares	4.11
Canceled and forfeited (in dollars per share) | $ / shares	18.47
Outstanding, end of period (in dollars per share) | $ / shares	10.68	$ 10.14
Options vested and exercisable (in dollars per share) | $ / shares	10.68
Options vested and expected to vest (in dollars per share) | $ / shares	$ 10.68
Weighted-Average Remaining Contractual Life and Aggregate Intrinsic Value
Weighted-average remaining contractual life, options outstanding	3 years 2 months 15 days	3 years 6 months 3 days
Weighted-average remaining contractual life, options vested and exercisable	3 years 2 months 15 days
Weighted-average remaining contractual life, options vested and expected to vest	3 years 2 months 15 days
Aggregate intrinsic value, options outstanding | $	$ 5,648	$ 13,197
Aggregate intrinsic value, options vested and exercisable | $	5,648
Aggregate intrinsic value, options vested and expected to vest | $	$ 5,648

Stock-Based Incentive Compens_4

Stock-Based Incentive Compensation Plans - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, stock options	$ 0		$ 0
Stock options granted (in shares)	0	0	0	0
Issuance of common stock related to employee stock purchase plan (in shares)	114,636	130,867	114,636	130,867
Issuance of common stock related to employee stock purchase plan	$ 1,472,000	$ 1,471,000	$ 1,500,000	$ 1,500,000
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)			6 months
Accrued compensation and related expenses for employee payroll deductions	200,000		$ 200,000		$ 400,000
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	36,900,000		$ 36,900,000
Unrecognized compensation cost, expected period for recognition (in years)			2 years 7 months 6 days
Restricted Stock Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period			1 year
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	$ 5,900,000		$ 5,900,000
Unrecognized compensation cost, expected period for recognition (in years)			2 years 2 months 12 days
Performance Shares | 2018 ESPP
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, 2024	Jun. 30, 2023
Black-Scholes option-pricing model assumptions
Expected volatility of common stock, minimum (percent)	47%	58%
Expected volatility of common stock, maximum (percent)	59%	73%
Expected volatility of peer companies, minimum (percent)	29%	33%
Expected volatility of peer companies, maximum (percent)	97%	141%
Correlation coefficient of peer companies, minimum	(1.00%)	(15.00%)
Correlation coefficient of peer companies, maximum	100%	100%
Risk-free interest rate, minimum (percent)	4.10%	3.90%
Risk-free interest rate, maximum (percent)	4.70%	5%
Minimum
Black-Scholes option-pricing model assumptions
Dividend yield (percent)	0.60%	0%
Maximum
Black-Scholes option-pricing model assumptions
Dividend yield (percent)	4.70%	1.30%

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, 2024 $ / shares shares
Restricted Stock Units
Number of Shares
Outstanding, beginning of period (in shares) | shares	1,899,790
Granted (in shares) | shares	1,041,308
Vested (in shares) | shares	(509,117)
Canceled and forfeited (in shares) | shares	(44,048)
Outstanding, end of period (in shares) | shares	2,387,933
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 19.93
Granted (in dollars per share) | $ / shares	18.35
Vested (in dollars per share) | $ / shares	21.19
Canceled and forfeited (in dollars per share) | $ / shares	20.10
Outstanding, end of period (in dollars per share) | $ / shares	$ 18.97
Performance Shares
Number of Shares
Outstanding, beginning of period (in shares) | shares	385,122
Granted (in shares) | shares	319,858
Vested (in shares) | shares	(94,439)
Canceled and forfeited (in shares) | shares	0
Outstanding, end of period (in shares) | shares	610,541
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 14.74
Granted (in dollars per share) | $ / shares	18.48
Vested (in dollars per share) | $ / shares	16.27
Canceled and forfeited (in dollars per share) | $ / shares	0
Outstanding, end of period (in dollars per share) | $ / shares	$ 16.47

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, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 6,398	$ 5,998	$ 13,428	$ 12,192
Cost of goods sold
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	257	161	491	298
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	2,709	2,702	5,930	5,612
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	823	748	1,643	1,500
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,609	$ 2,387	$ 5,364	$ 4,782

Stock-Based Incentive Compens_8

Stock-Based Incentive Compensation Plans - Common Stock Warrants Activity (Details) - $ / shares	6 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Warrants outstanding, beginning balance (in shares)	85,139	85,139
Warrants Issued (in shares)	0
Warrants Exercised (in shares)	0
Warrants Expired (in shares)	0
Warrants outstanding, ending balance (in shares)	85,139
Warrants Issued 3/1/2017
Class of Warrant or Right [Line Items]
Price per Share (in dollars per share)		$ 5.94
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Warrants outstanding, beginning balance (in shares)	1,388	1,388
Warrants Issued (in shares)	0
Warrants Exercised (in shares)	0
Warrants Expired (in shares)	0
Warrants outstanding, ending balance (in shares)	1,388
Warrants Issued 11/26/2014
Class of Warrant or Right [Line Items]
Price per Share (in dollars per share)		$ 16.47
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Warrants outstanding, beginning balance (in shares)	6,680	6,680
Warrants Issued (in shares)	0
Warrants Exercised (in shares)	0
Warrants Expired (in shares)	0
Warrants outstanding, ending balance (in shares)	6,680
Warrants Issued 10/20/2015
Class of Warrant or Right [Line Items]
Price per Share (in dollars per share)		$ 16.47
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Warrants outstanding, beginning balance (in shares)	41,650	41,650
Warrants Issued (in shares)	0
Warrants Exercised (in shares)	0
Warrants Expired (in shares)	0
Warrants outstanding, ending balance (in shares)	41,650
Warrants Issued 11/9/2015
Class of Warrant or Right [Line Items]
Price per Share (in dollars per share)		$ 16.47
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Warrants outstanding, beginning balance (in shares)	25,709	25,709
Warrants Issued (in shares)	0
Warrants Exercised (in shares)
Warrants Expired (in shares)	0
Warrants outstanding, ending balance (in shares)	25,709
Warrants Issued 12/22/2016
Class of Warrant or Right [Line Items]
Price per Share (in dollars per share)		$ 10.03
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Warrants outstanding, beginning balance (in shares)	9,712	9,712
Warrants Issued (in shares)	0
Warrants Exercised (in shares)	0
Warrants Expired (in shares)	0
Warrants outstanding, ending balance (in shares)	9,712

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, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Earnings Per Share [Abstract]
Net loss	$ (8,939)	$ (10,904)	$ (11,206)	$ (11,125)	$ (19,843)	$ (22,331)
Weighted-average number of common shares used to compute basic net loss per share (in shares)	41,317,627		37,864,185		41,126,009	36,399,309
Weighted-average number of common shares used to compute diluted net loss per share (in shares)	41,317,627		37,864,185		41,126,009	36,399,309
Net loss per share, basic (in usd per share)	$ (0.22)		$ (0.30)		$ (0.48)	$ (0.61)
Net loss per share, diluted (in usd per share)	$ (0.22)		$ (0.30)		$ (0.48)	$ (0.61)

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, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
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)	4,235,877	3,713,763	4,235,877	3,713,763
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)	1,088,277	1,269,147	1,088,277	1,269,147
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)	2,998,474	2,320,750	2,998,474	2,320,750
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)	63,987	38,727	63,987	38,727
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)	85,139	85,139	85,139	85,139

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Related Party Transaction [Line Items]
Research and development	$ 4,352,000	$ 3,656,000	$ 8,697,000	$ 6,947,000
Related party
Related Party Transaction [Line Items]
Research and development		0		0
Term of agreement			10 years
Royalties		$ 100,000		$ 100,000

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Income tax provision	$ 0	$ 0	$ 0	$ 0

Subsequent Event (Details)

Subsequent Event (Details)	Jul. 18, 2024 USD ($) ft²	Jun. 30, 2024
Subsequent Event [Line Items]
Extension term		5 years
Subsequent event
Subsequent Event [Line Items]
Office space | ft²	21,848
Extension term	14 months
Base rent | $	$ 43,696