Abstract
Four knees from three patients had metal-backed patellar component failure after Miller-Galante type I total knee arthroplasty (M-G I TKA). The failure led to considerable wear of the femoral component and to metal-induced synovitis metallosis. A metal-backed patellar component from one knee without metallosis was replaced with an allpolyethylene patella component. Three knees with metallosis were replased from a M-G I femoral component, metal-backed patellar component and worn tibial surface to a M-G II femoral component, all polyethylene patella component and M-G II tibial surface.
The factors of failure were from the patient (activity, weight, range of motion etc.), surgical technique (lateral release etc.), and patellar implant design (the use of metal back, the depth of groove etc.).
Metal-backed patellar component failure is a serious complication of TKA and will increase in number. Absorbed metal ion may damage human body. We conclude that revision should be perfomed as soon as metallosis occurs.
