Failure of the hinge mechanism in total elbow arthroplasty

Hypothesis: Total elbow arthroplasty (TEA) has become an accepted means of dealing with intractable elbow arthritis. The Coonrad-Morrey elbow prosthesis has become the workhorse for management of elbow arthropathy. Its successful initial use in rheumatoid patients has evolved, as has its design, to allow use in osteoarthritic patients and patients with posttraumatic arthritis. More active patients with elbow arthropathy are also treated using TEA. Prior design flaws led to central bushing failure and resulted in a redesign of the implant. However, the newer design has been noted to demonstrate a new mode of failure that appears to be more prevalent in active patients with osteoarthritis and posttraumatic arthritis. The authors hypothesize that the mechanical properties of the second generation hinge mechanism are inadequate to resist the high stresses placed upon it by some active patients treated for osteo- and post-traumatic arthritis. Materials and methods: Since 2000, 2 senior surgeons at Cleveland Clinic performed 82 TEAs, 64 in osteoarthritic or posttraumatic patients. Outcomes are reviewed. Results: Five patients demonstrated failure of the central locking and bushing components, with instability and dissociation requiring revision surgery. Two of these patients had secondary failure and required repeat revision using a more substantial central axis with lock washer and set screw. Discussion: The mode of failure and radiographic and clinical findings demonstrate that younger patients with a more active lifestyle are at risk for central axis and bushing failure. It is recommended that younger, more active patients be monitored indefinitely at 6-month intervals and counseled about the risk of potential failure and the need to limit forces across the reconstructed elbow. Results: These failures indicate the need for alternative designs in younger, active patients. Level of evidence: Level IV, Case Series; Treatment Study 2010 Journal of Shoulder and Elbow Surgery Board of Trustees.