Posterior Tibial Polyethylene Fracture in Cruciate-Retaining Total Knee Arthroplasty

Introduction One of the common prostheses for primary total knee arthroplasty (TKA) is a cruciate-retaining (CR) design. The tibial polyethylene inserts commonly used in TKA are made of ultra-high molecular weight polyethylene (UHMWPE). The CR TKA design retains the posterior cruciate ligament (PCL), which is believed to provide increased stability, promote femoral roll back, improve proprioception, and enhance stair-climbing ability. Delamination, adhesive wear, and abrasive wear of the polyethylene component are common mechanisms of failure, but fracture of the component at the posterior side in a CR TKA is rare. The cause of this type of failure is often multifactorial. This case report presents a case of posteromedial polyethylene fracture in a CR TKA.