Scintigraphic evaluation in total knee failure secondary to severe metallosis

The scintigraphic findings are described for a patient with severe metallosis in a failed noninfected total knee arthroplasty secondary to metal-metal friction between the femoral and tibial components as a result of polyethylene wear. Technetium-99m phosphate and gallium-67 citrate scans were positive in incongruent uptake areas. This uptake is classically associated with septic loosening. The recommendation is made that metallosis be suspected before surgery as a possible cause of a false positive scan where sequential technetium-gallium scans are employed.