This study reviews the long-term outcome of total elbow arthroplasties performed in patients with rheumatoid arthritis using the third generation unconstrained Kudo total elbow prosthesis. 50 elbows in 47 patients with rheumatoid arthritis were evaluated at a mean of 13 years post- operatively (range, 11–16 years). This retrospective review from Japan involved 4 surgeons with similar operative procedures, except 31 elbows had complete transection of the ulnar collateral ligament and 19 elbows had preservation of the anterior oblique component of the ulnar collateral ligament. There was a 90 percent overall survival rate at 16 years. The Mayo Elbow Performance Score improved from 43 points pre-operatively to 77 points at final follow-up. 100 percent of the humeral components had radiolucencies compared to 8.9 percent of the ulnar components. The mean degrees of flexion, supination, and pronation were 133 degrees, 59 degrees, and 42 degrees, respectively, at latest follow-up. An average flexion contracture of 49 degrees was significantly greater in the group with the retained ulnar collateral ligament compared to 40 degrees in the patients who had release of the ulnar collateral ligament. There were few complications with only two patients having persistent skin breakdown over the olecranon. There were no apparent deep infections, no revisions of the prosthesis, and no prosthetic dislocations despite 6 elbows pre-operatively being grossly unstable.
This study reports remarkably good long-term follow-up using the Kudo unconstrained prosthesis. Although the humeral component had 100 percent radiographic lucencies noted at long term follow-up, there were no revisions, no dislocations, and minimal complications. Although not specifically commented on, there were no cases of triceps insufficiency. The authors used a triangularly shaped distally based flap of the triceps tendon. There was, however, a high rate of flexion contracture, which measured 49 degrees in the group with retained ulnar collateral ligament. Patients with complete transection of the ulnar collateral ligament had slightly greater extension, without clinical evidence of instability. This is presumably due to the mediolateral stability of this unconstrained prosthesis, which does not specifically depend on the ulnar collateral ligament.