4. Select Balance Sheet Details

Inventories

Inventories consist of the following (in thousands):


	September 30, 2011							December 31, 2010
	Gross		Reserve for excess and obsolete			Net		Gross		Reserve for excess and obsolete			Net
Raw materials	$	3,476	$	—		$	3,476	$	3,821	$	—		$	3,821
Work-in-process		2,465		—			2,465		2,242		—			2,242
Finished goods		54,832		(11,990	)		42,842		56,602		(11,030	)		45,572

Inventories, net	$	60,773	$	(11,990	)	$	48,783	$	62,665	$	(11,030	)	$	51,635

Property and Equipment

Property and equipment consist of the following (in thousands except as indicated):


	Useful lives (in years)		September 30, 2011			December 31, 2010
Surgical instruments		4	$	56,279		$	53,155
All other property and equipment		various		23,791			22,450

				80,070			75,605
Less accumulated depreciation and amortization				(45,748	)		(37,165	)

Property and equipment, net			$	34,322		$	38,440

Total depreciation expense was $3.7 million and $3.6 million for the three months ended September 30, 2011 and 2010, respectively. Total depreciation expense was $11.1 million and $9.5 million for the nine months ended September 30, 2011 and 2010, respectively.

Intangible Assets

Intangible assets consist of the following (in thousands except as indicated):


	Useful lives (in years)		September 30, 2011			December 31, 2010
Developed product technology		5-8	$	23,352		$	23,030
Distribution rights		3		4,313			4,148
Intellectual property		5		1,004			1,004
License agreements		1-7		6,487			5,100
Core technology		10		3,670			3,548
In-process technology		Indefinite		1,767			1,708
Trademarks and trade names		5-9		3,827			3,722
Customer-related		15		16,160			15,792
Distribution network		10		1,614			1,614
Physician education programs		10		3,127			3,022
Supply agreement		10		225			225

				65,546			62,913
Less accumulated amortization				(23,718	)		(19,765	)

Intangible assets, net			$	41,828		$	43,148

Total amortization expense was $1.3 million and $1.0 million for the three months ended September 30, 2011 and 2010, respectively. Total amortization expense was $3.8 million and $3.0 million for the nine months ended September 30, 2011 and 2010, respectively.

The future expected amortization expense related to intangible assets as of September 30, 2011 is as follows (in thousands):


Year Ending December 31,
Remainder of 2011	$	1,110
2012		4,440
2013		4,394
2014		4,291
2015		4,139
Thereafter		21,687

Total future expected amortization expense		40,061
Add: In-process technology		1,767

Total	$	41,828