Implant arthroplasty of the hand: Retrospective and prospective considerations

Small joint arthroplasty has lagged behind the development of that in large joints because of their small sizes, different shapes, presence within kin etic chains, complex soft tissue investments, presence of adjacent rays, se condary displacement and contracture, and the differing requirements of deg enerative and rheumatoid arthritis. Prosthetic development must take into c onsideration range of motion, stability, tendon moment arms, fixation, ease of implantation, biocompatibility, wear and strength characteristics, and soft tissue reconstruction. The metacarpophalangeal, interphalangeal, and t rapeziometacarpal joints each present different problems in the design of k inematic equivalent prostheses. One-piece polymeric designs have advantages in cost, adaptability, and known performance but show degradation of funct ion with time. Total joint designs have the potential of better simulating normal joint function but have shown tendencies to subsidence, loosening, a nd breakage. The rigidity of hinge joints limits the damping of out-of-plan e forces and places greater stress on bone-stem interfaces, whereas global designs have poor constraint features. (J Hand Surg 2000;25A:796-816. Copyr ight (C) 2000 by the American Society for Surgery of the Hand.).