Thigh mass associated with polyethylene wear-induced osteolysis after cementless total hip arthroplasty

Polyethylene wear-induced osteolysis is a common complication of total hip arthroplasty. We report a case of a patient who had an extensile osteolytic lesion that presented as a tumor-like thigh mass associated with a polyethylene wear debris-induced granuloma 18 years after cementless total hip arthroplasty. The patient received a proximally porous-coated stem that had not fully circumferentially coated surface, and, therefore, polyethylene wear particles could be transported to the distal stem tip area by fluid pressure generated from the hip joint during activity. Biologic reaction to polyethylene wear particles had then produced the extensile osteolytic lesion extending to the extramedullary diaphysis of the femur that presented as a solitary thigh mass mimicking a soft tissue tumor. To the authors' knowledge, no case of a thigh mass and osteolytic femoral lesion associated with polyethylene wear after total hip arthroplasty has previously been reported.