A new patella prosthesis. Design and application.

The new patella prosthesis design is based on an anatomical study of 80 arthritic patellas and on the normal patellofemoral contact area under loading in cadaver knees. The metal dome-shaped prosthesis is attached by a central pin. The patellar prosthesis is constructed either of metal or plastic for use in combination with the Hospital for Special Surgery design of total knee prosthesis. Methylmethacrylate is used to supplement the fixation after resection of the abnormal patellar articular surface. The fixation tests gave excellent laboratory results for contact area and stability. The prosthesis has been used in 19 cases with encouraging early results.