Total Knee Arthroplasty Complicated by Posterior Dislocation of a Polyethylene Insert and Neurovascular Compromise

Dislocation of the polyethylene insert is a rare complication of total knee arthroplasty (TKA), which has only been described in a handful of case reports. Here, we describe a report of a 55-year-old woman presenting 13 months after the primary TKA with signs of neurovascular compromise. A magnetic resonance image showed posterior extrusion of her polyethylene insert causing a mass effect on the gastrocnemius muscle and the popliteal neurovascular bundle. A multidisciplinary team including a joint reconstruction surgeon, vascular surgeon, and nerve specialist performed a revision TKA with peroneal nerve decompression. The polyethylene insert was noted to be dislocated, rotated 90 degrees, and incarcerated in the posterior knee.