Lessons Learned from Retrieved Total Elbow Implants
SourceTotal elbow replacement is a viable option for joint reconstruction as treatment for arthritis or severe fractures, though the clinical results are inferior to those achieved in hip and knee replacement. Few studies have been performed analyzing retrieved total elbow components, and those few have concentrated on explaining failure modes. In our work, we have applied retrieval analysis to the gold standard design of elbow replacement, the Coonrad-Morrey, using the results to determine the primary loading modes and to quantify the deformation in the polyethylene bushings. Finite element analyses were then used to replicate the loading and deformation observed on the retrievals. Finally, a novel design approach was proposed, one that will enhance the wear and deformation of the polyethylene bearing and constraint surfaces while also enhancing the creation of internal moments at the joint to help resist the externally applied varus moments that are the dominant mechanical burden during activities of daily living. As this design hopefully reaches clinical use, future retrieval studies will help validate the design approach, thus completing the design cycle.