Silastic arthroplasty for avascular necrosis of the carpal lunate

The substitution of a diseased carpal lunate by a silastic implant (Swanson design) was performed in 70 patients. Twenty cases with a median follow-up of 48 months generally showed an increase in the range of motion of the wrist. There was disabling weakness of grip in one patient. Subluxation of the implant occurred in 2 cases, but this did not compromise the final result. Instability of the scaphoid was observed in 50% of the cases, before and after operation. There were no adverse reactions to the implant.