CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities:
Net loss	$ (39,971)	$ (18,347)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	5,354	5,066
Stock-based compensation	7,566	3,442
Amortization of debt discount and debt issuance costs	2,332	1,571
Amortization of right-of-use asset	678
Provision for doubtful accounts	190	131
Provision for excess and obsolete inventory	6,451	1,612
Deferred income tax benefit	2	(1,227)
Gain on settlement		(6,168)
Beneficial conversion feature from convertible notes	242
Gain (loss) on disposal of instruments	478	(275)
Accretion to contingent consideration	289	646
Changes in operating assets and liabilities:
Accounts receivable, net	(526)	2,527
Inventories, net	(10,751)	(3,117)
Prepaid expenses and other current assets	263	589
Other assets	127	(48)
Other long-term assets	(2,864)
Accounts payable	3,541	922
Accrued expenses and other	3,313	(316)
Lease liability	2,528
Other long-term liabilities	(3,296)	(3,528)
Net cash used in operating activities	(24,054)	(16,520)
Investing activities:
Purchases of property and equipment	(10,437)	(3,297)
Cash paid for acquisition of intangible assets		(150)
Cash received from sale of equipment		348
Net cash used in investing activities	(10,437)	(18,202)
Financing activities:
Proceeds from public offering, net	53,974
Proceeds from sale of common stock, net	2,073	51,554
Borrowings under lines of credit	81,723	67,804
Repayments under lines of credit	(81,161)	(68,581)
Principal payments on capital lease obligations	(22)	(87)
Proceeds from issuance of term debt, net	9,700
Principal payments on term loan	(3,068)	(3,275)
Net cash provided by financing activities	63,219	47,415
Effect of exchange rate changes on cash	61	(48)
Net increase (decrease) in cash	28,789	12,645
Cash at beginning of period, including discontinued operations	29,054	22,466
Cash at end of period, including discontinued operations	57,843	35,111
Supplemental disclosure of cash flow information:
Cash paid for interest	4,342	3,387
Cash paid for income taxes	102	109
Purchases of property and equipment in accounts payable	1,297	1,277
Common stock warrants issued with term loan draw	13,664
SafeOp Surgical, Inc.
Adjustments to reconcile net loss to net cash used in operating activities:
Accretion to contingent consideration	300
Investing activities:
Cash paid for acquisition of SafeOp Surgical, Inc.		(15,103)
Supplemental disclosure of cash flow information:
Common stock issued for achievement of SafeOp contingent consideration	$ 2,889	$ 1,446