A rare etiology of posterolateral pain following total knee arthroplasty

Numerous studies and publications have addressed the etiology of postoperative pain after total knee arthroplasty (TKA). The most frequently cited etiologies, aside from infection, primarily concerned the implants: loosening, malpositioning, or misalignment. More specifically, in cases of posterolateral pain, the most common identified etiology is malpositioning of the tibial component. The posterior overhang can cause impingement on soft tissues, particularly the popliteus tendon. The impact can involve the metallic component or the polyethylene, which is more difficult to detect because radiologically the implants appear to be the correct size. The solution is generally surgical, ranging from arthroscopy to revision TKA. The case presented here is far from ordinary and illustrates a very different problem, which we must consider before undertaking a risky revision.