Metal sensitivity in patients with a hinge arthroplasty of the knee

Fifty patients who had received a hinge arthroplasty of the knee were investigated for possible metal sensitivity. Patients were patch tested against all the metal constituents of the prosthesis. Positive patch tests were found in 32% of patients. Seventeen patients had either lossening or a persistent sterile discharge from the knee. No correlation was found between these complications and metal sensitivity. It was concluded that metal sensitivity is probably not a primary factor in the pathogenesis of complications, particularly loosening.