In an analysis of thirty-seven arthroplasties of the knee, there were eleven good results (30 per cent.), eight fair results (22 per cent.), and eighteen failures (48 per cent.).

Particularly poor candidates for arthroplasty have been those patients with polyarticular ankylosis resulting from atrophic arthritis. Ankylosis due to extension of an osteomyelitic process about the knee joint gave similarly poor results.

The most favorable results from the operation were obtained in cases where the knee joint was involved secondarily by a blood-borne infection.

Concerning the operative technique, the medial parapatellar incision combined with Campbell's method of joint reconstruction was adopted as the procedure of choice. The importance of resecting adequate bone for maintaining the new joint space, accurate modeling of the opposing articular surfaces for joint alignment, and retaining the lateral capsular and ligamentous structures for stability cannot be emphasized too highly.

The postoperative complications which most frequently led to failure were the reactivation of the arthritic or infectious process and infection introduced by the operative procedure.

From the analysis of the above cases, it is apparent that a new joint of sufficient mobility and stability, with freedom from pain, is not a constant result. However, the unusual benefits derived from a successfully mobilized knee make the operation of arthroplasty of great value in the carefully selected cases of ankylosis. The operation should be advised only after the patient has been made aware of its limitations.