Distal femur replacement after catastrophic failure of a total knee arthroplasty.

Catastrophic implant failure is a rare complication after total knee arthroplasty (TKA) that can lead to metallosis and pseudotumour formation requiring complex revision surgery. This case report describes a man in his 60s who presented with progressive knee pain, a squeaking implant and ligamentous instability 20 years post-primary TKA. Imaging demonstrated polyethylene failure, tibial baseplate breakage, extensive osteolysis and metallosis. The patient underwent a revision procedure with a distal femur replacement (DFR). Postoperatively he had no complications, re-admissions or revision surgery. At 4 years post DFR, he remained asymptomatic with excellent functional outcomes (Oxford Knee Score 45 out of 48; Forgotten Joint Score 98 out of 100). This case highlights DFR as a viable salvage option in appropriately selected patients where conventional revision TKA is not possible.