[Long-term results after the surgical treatment of saddle joint arthrosis with Swanson's silastic prosthesis].

The use of a silastic implant in resection arthroplasty of the carpometacarpal joint of the thumb allows the joint space to be preserved. With the Swanson type arthroplasty relief of pain, good function, as well as stability and improved pinch force can be obtained, avoiding the consequence of carpal instability by narrowing of the joint space associated with resection of the trapezium alone or in combination with tendon interposition arthroplasty. The two main problems associated with Swanson arthroplasty are prosthetic dislocation and longterm stability of the prosthesis itself. The joint surface of the prosthesis wears out asymmetrically, and mild to severe foreign body reactions can be seen in the carpal bones, mainly the scaphoid. Clinical and radiological results of a series of 77 operations in 65 patients from 1975-1981 are presented and discussed.