Proximal interphalangeal joint arthroplasty.

Prosthetic implant arthroplasty of the proximal interphalangeal (PIP) joint has a limited role in the reconstruction of the rheumatoid hand. Ninety-three PIP joint arthroplasties, including 56 Flatt, 30 Swanson, and seven Niebauer implants, were reviewed with postoperative follow-up periods averaging 6.2 years. The average maximum extension/flexion for the prostheses were Flatt, 28 degrees/45 degrees; Swanson, 1 degree/40 degrees; and Niebauer, 3 degrees/26 degrees. The average active ranges of motion for the prosthetic groups were Flatt, 15 degrees; Swanson, 37 degrees; and Niebauer, 19.5 degrees. Analysis of active motion at intervals of up to ten years indicated gradually decreasing active motion for each prosthesis. Comparison of preoperative motion with motion three years after operation indicated a decrease in the Flatt prosthesis group, from 35 degrees to 20 degrees. Radiographically, cortical perforation by the prosthesis was common with the Flatt prosthesis (80%), and recurrent swan-neck deformity was frequent with the Swanson spacer (27%). Despite suboptimal clinical results, patient satisfaction was high, and the ability of patients to perform activities of daily living was acceptable.