Radial head replacement in capitellocondylar total elbow arthroplasty. 2- to 6-year follow-up evaluation in rheumatoid arthritis.

We reviewed six capitellocondylar metal-to-plastic total elbow replacement prostheses with radial head components, implanted in patients with rheumatoid arthritis. At an average of 4.7 +/- 1.5 years, relief of pain, improvement of function, and a functional range of motion were preserved. Five of the six elbows (83%) were clinically rated good or excellent. Radiolucent lines were seen at the bone-cement interface in 50% of the humeral component stems and in all ulnar component boats within 2 years after surgery; none had progressed at subsequent examination. Most were less than or equal to 1 mm wide, and none were associated with clinical deterioration. Only one of the humeral components was radiographically loose. No radiolucent lines were seen along the stems of the ulnar or radial components. There were no postoperative dislocations when the radial component was used, presumably because the prosthetic radial head provided increased constraint. None of these elbows have required revision. Radial head replacement in capitellocondylar arthroplasty had been discontinued because radiolucent lines were observed at early review. However, the absence of clinical failure, dislocation, or progression of radiolucency at long-term follow-up examination favor radial head replacement in primary unconstrained total elbow arthroplasty.