Summary of Significant Accounting Policies	3 Months Ended
Mar. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies The Company’s significant accounting policies are described in Note 2 to its audited consolidated financial statements for the year ended December 31, 2013, which are included in the Company’s Annual Report on Form 10-K that was filed with the SEC on March 20, 2014. Except as discussed below, these accounting policies have not significantly changed during the three months ended March 31, 2014. Restricted Cash In March 2014, the Company borrowed and set aside cash for the payment of a portion of the Orthotec litigation settlement (see Note 6) as limited by the terms of the facility agreement that we entered into with Deerfield on March 17, 2014 (see Note 5). The Company classified this cash as restricted, because it may not be used for purposes other than payments of amounts due under the Orthotec litigation settlement agreement. Warrants for Common Stock Common stock warrants that contain compliance covenants and cash payment obligations are classified as common stock warrant liabilities on the consolidated balance sheet. The Company records the warrant liability at fair value and adjust the carrying value of these common stock warrants to their estimated fair value at each reporting date with the increases or decreases in the fair value of such warrants at each reporting date recorded as other income (expense) in the consolidated statement of operations. Recent Accounting Pronouncements In March 2013, the Financial Accounting Standards Board (“FASB”) issued guidance on a parent company’s accounting for the cumulative translation adjustment upon derecognition of a subsidiary or group of assets within a foreign entity. This new guidance requires that the parent release any related cumulative translation adjustment into net income only if the sale or transfer results in the complete or substantially complete liquidation of the foreign entity in which the subsidiary or group of assets had resided. The amendments became effective for the Company beginning January 1, 2014. The Company adopted this guidance and the adoption did not have any impact on the Company's financial statements.

Summary of Significant Accounting Policies

The Company’s significant accounting policies are described in Note 2 to its audited consolidated financial statements for the year ended December 31, 2013, which are included in the Company’s Annual Report on Form 10-K that was filed with the SEC on March 20, 2014. Except as discussed below, these accounting policies have not significantly changed during the three months ended March 31, 2014.

Restricted Cash

In March 2014, the Company borrowed and set aside cash for the payment of a portion of the Orthotec litigation settlement (see Note 6) as limited by the terms of the facility agreement that we entered into with Deerfield on March 17, 2014 (see Note 5). The Company classified this cash as restricted, because it may not be used for purposes other than payments of amounts due under the Orthotec litigation settlement agreement.

Warrants for Common Stock

Common stock warrants that contain compliance covenants and cash payment obligations are classified as common stock warrant liabilities on the consolidated balance sheet. The Company records the warrant liability at fair value and adjust the carrying value of these common stock warrants to their estimated fair value at each reporting date with the increases or decreases in the fair value of such warrants at each reporting date recorded as other income (expense) in the consolidated statement of operations.

Recent Accounting Pronouncements

In March 2013, the Financial Accounting Standards Board (“FASB”) issued guidance on a parent company’s accounting for the cumulative translation adjustment upon derecognition of a subsidiary or group of assets within a foreign entity. This new guidance requires that the parent release any related cumulative translation adjustment into net income only if the sale or transfer results in the complete or substantially complete liquidation of the foreign entity in which the subsidiary or group of assets had resided. The amendments became effective for the Company beginning January 1, 2014. The Company adopted this guidance and the adoption did not have any impact on the Company's financial statements.