[Aseptic loosening due to osteolytic reaction to polyethylene of o total knee prosthesis]

Total knee replacement (TKR) is currently the gold standard in the surgical management of degenerative knee diseases. It is a reliable operation with 95 % good results at 10 years after surgery. Aseptic loosening is the primary cause of TKR failure. It results from a periprosthetic osteolytic reaction secondary to the host's reaction to the wear particle of the prosthesis and responsible for an imbalance in osteoformation and osteolysis. Polyethylene (PE) is responsible for the majority of periprosthetic reactions but the release of metal particles may play an underestimated role with the risk of systemic manifestations. The first clinical signs appear on average 7 years after prosthesis placement. Radio-clinical assessment may be normal in the early stages. Infectious process must be systematically excluded before concluding to another type of complication.