CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating activities:
Net loss	$ (18,347)	$ (11,349)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	5,066	5,536
Stock-based compensation	3,442	1,669
Amortization of debt discount and debt issuance costs	1,571	2,107
Provision for doubtful accounts	131	(145)
Provision for excess and obsolete inventory	1,612	1,640
Deferred income tax expense	(1,227)	(1)
Gain on settlement	(6,168)
Gain on sale of assets		(856)
(Gain) loss on disposal of instruments	(275)	1,043
Accretion to contingent consideration	646
Changes in operating assets and liabilities:
Accounts receivable, net	2,527	5,354
Inventories, net	(3,117)	(1,294)
Prepaid expenses and other current assets	589	2,745
Other assets	(48)	297
Accounts payable	922	(3,597)
Accrued expenses and other	(316)	(11,552)
Other long-term liabilities	(3,267)
Deferred revenue	(261)	289
Net cash used in operating activities	(16,520)	(8,114)
Investing activities:
Purchases of property and equipment	(3,297)	(7,185)
Cash paid for acquisition of SafeOp Surgical, Inc.	(15,103)
Cash paid for acquisition of intangible assets	(150)
Cash received from sale of equipment	348	869
Net cash used in investing activities	(18,202)	(6,316)
Financing activities:
Borrowings under lines of credit	67,804	70,547
Repayments under lines of credit	(68,581)	(74,056)
Principal payments on capital lease obligations	(87)	(353)
Proceeds from sale of stock, net	51,554	17,210
Principal payments on term loan	(3,275)	(3,328)
Net cash provided by financing activities	47,415	10,020
Effect of exchange rate changes on cash	(48)	254
Net increase (decrease) in cash	12,645	(4,156)
Cash at beginning of period, including discontinued operations	22,466	19,593
Cash at end of period, including discontinued operations	35,111	15,437
Supplemental disclosure of cash flow information:
Cash paid for interest	3,387	3,568
Cash paid for income taxes	109	90
Purchases of property and equipment in accounts payable	$ 1,277	2,240
Common stock issued for acquisition of intangible assets		$ 473