Paresis of the Peroneal Nerve: A Rare But Severe Long-term Complication of Polyethylene Wear in Knee Arthroplasty.

One of the most important limiting factors in the long-term success of total knee arthroplasty is polyethylene wear. Particles of the polyethylene inserts have been shown to elicit a foreign body response, which produces bone resorption and osteolysis, ultimately leading to loosening and component failure. The authors report on a case of an elderly patient who underwent a total knee arthroplasty almost 2 decades ago. Clinical and radiological checkups of the knee had not been performed recently. He now presented with a painful and swollen knee, recurrent joint effusion and swelling of the lower leg, and paresis of the peroneal nerve. Radiological examination showed asymmetric wear of the polyethylene insert and pronounced periprosthetic osteolysis of the proximal tibia and the distal femur. Furthermore, a large ganglion on the anterolateral aspect of the lower leg, resulting in pressure on the peroneal nerve, was detected on ultrasound examination. Open excision of the ganglion was performed initially, followed by 1-stage revision knee arthroplasty using a modular system a few weeks later. This case shows a rare but severe long-term complication of total knee arthroplasty and highlights the importance of regular clinical and radiological checkups after total joint replacements, even for asymptomatic patients and especially in the long term (ie, beyond 10 years after implantation). The current case shows that wear of the polyethylene insert may also lead to ganglion formation that causes paresis of the peroneal nerve. [Orthopedics. 2017; 40(3):e538-e540.].