Anterior dislocation after total knee arthroplasty: a case report.

We report a case of anterior dislocation of an 11-year-old total knee arthroplasty in a 52-year-old woman with severe rheumatoid arthritis and osteoporosis. It was noteworthy that the mechanism of dislocation was unique in that massive wear of ultra-high-molecular-weight polyethylene, avulsion injuries of the medial collateral ligament and patellar tendon, and a stress fracture of the fibula secondary to the increased posterior tilt angle eventually caused anterior dislocation of the left knee without obvious trauma or infection.