[Rare cause of knee pain after total knee arthroplasty].

A painful knee after total knee arthroplasty may have various causes. In addition to commonly occurring causes, such as infections, aseptic loosening, implant failure or typical anterior knee pain, rare causes also have to be taken into account. We report a previously unknown cause of knee pain after total knee replacement involving a non-resected medial meniscus, which was sandwiched between the medial condyle of the femur and the inlay of the prosthesis and caused pain typical for a medial meniscus. After arthroscopic meniscectomy the patient was symptom-free.