Abstract
Many causes of painful knee following total knee arthroplasty (TKA) have been reported. We report a case of posterolateral pain occurring after TKA that was successfully treated by resecting the popliteus tendon. A 63-year-old woman with right knee osteoarthritis underwent TKA in July 2009. The angle of the lift-off between the femoral and tibial components was 0° Seven months after the first operation, the patient's range of motion was limited to 15°-100°, and pain developed in the lateral posterior part of the knee with matching tenderness in the right popliteus tendon. Since impingement between the popliteus tendon and the posterior condyle of the femoral component was assumed and articular contracture was present, joint mobilization and the resection of the popliteus tendon compressed from the outer edge of the posterior condyle of the femoral component were performed at 9 months after the first operation. Two months after the final surgery, the posterolateral pain had disappeared and the patient's range of movement had improved to 5°-125°. No differences between the knees were observed using a dial test. From the epicondylar view, the angle of lift-off remained the same at 0°. In this case, impingement of the posterior condyle of the femoral component and the popliteus tendon after TKA caused posterolateral pain that was successfully treated by resecting the popliteus tendon. Postoperatively, varus instability, changes in the lift-off angle, and bilateral differences in the dial test results were not observed, and therefore lateral and posterolateral instability were assumed not to have occurred. To prevent the postoperative impingement of the popliteus tendon in such cases, additional popliteus tendon resection should be considered in cases of impingement occurring during primary TKA.
