Popliteal cyst in a patient with total knee arthroplasty: a case report and review of the literature.

We report a case of total knee arthroplasty (TKA) failure presenting initially as a large popliteal cyst without bony destruction in a 66-year-old woman. A foreign body gigantocellular inflammatory reaction against polyethylene wear particles was found on histology. The size of the cyst and the absence of bony destruction can be due to an exclusive early intramuscular granulomatous reaction. Progressive loosening of the femoral component and narrowing of the joint space heralded the TKA failure.