BACKGROUND: Metal hypersensitivity is an uncommon complication after total knee arthroplasty (TKA) that can lead to significant functional impairment and aseptic prosthesis failure.

CASE REPORT: We describe a 70-year-old patient who presented with persistent pain, swelling, and instability 2 years after a primary TKA. The patient had a history of metal hypersensitivity following bilateral metal-on-metal total hip arthroplasty (THA) that was revised to ceramic-on-polyethylene implants. Knee radiographs showed severe osteolysis with implant loosening. Serum cobalt was elevated and serum chromium was significantly elevated, while joint aspiration and inflammatory marker levels ruled out a periprosthetic infection. Revision TKA was performed, with intraoperative tissue pathology and postoperative leukocyte transformation testing confirming metal hypersensitivity as the cause for aseptic implant failure.

CONCLUSIONS: This case report demonstrates the clinical and laboratory signs that suggest metal hypersensitivity in total knee arthroplasty and the potential for joint function restoration with revision surgery.

Keywords: Arthroplasty, Replacement, Knee - instrumentation, Hypersensitivity - complications, Knee Prosthesis - adverse effects, Metals, Osteoarthritis, Knee - surgery, Prosthesis Design - adverse effects, Reoperation, Treatment Failure