Partial trapeziectomy and interpositional arthroplasty for trapeziometacarpal osteoarthritis of the thumb.

Partial excision including the articular surface of the trapezium and interpositional arthroplasty using one half of the flexor carpi radialis tendon was done in 36 hands. The joint capsule was reattached to the trapezium and the thumb immobilized for 4 weeks post-operatively. No ligament reconstruction was done. 30 hands (83.6%) had complete relief of pain. The average post-operative pinch strength was 11 lb. Three patients who complained of weakness of pinch had hyperextension of the MP joint. Correction of MP hyperextension is recommended to improve pinch strength. The outcome of this operation is comparable to any of the techniques described in the literature. The technique is simple and easy to perform. Since the capsule is closed the operation is truly an interpositional arthroplasty.