Femoral Condyle Insufficiency Fracture After Total Knee Arthroplasty Using a Stemless Femoral Component With a Midlevel Constraint Articular Surface.

Midlevel constraint prostheses have provided increased varus/valgus and rotational stability for patients with severe deformity or ligamentous instability undergoing total knee arthroplasty (TKA). Here we present a series of 5 patients, 2 in detail, who underwent a primary TKA with a midlevel constraint articular surface and a primary femoral component without stem extension who all suffered isolated medial femoral condyle insufficiency fractures. All 5 TKAs were performed in females with both preoperative valgus deformity and flexion contractures. Patients had an average age of 74.4 years, height 62.4 in, and weight 156.2 lbs. Revision TKA was performed in 4 of 5 cases. As a result of these cases, we now routinely consider implanting a stemmed femoral component in this population with osteoporotic medial femoral condyles.