 Besides the use of the flexor carpi radialis tendon, several materials can serve as the interposition tissue including Gore-Tex, silicone and other types of metal or polymer implants. The use of Gore-Tex, silicone and metal implants, have been shown to carry high complication rates secondary to synovitis and mechanical failure combined with poor patient outcomes. A study about a porcine collagen xenograft was terminated prematurely because of poor outcomes and adverse immunologic reactions. 