Failed total knee arthroplasty treated by arthrodesis of the knee using the Ace-Fischer apparatus.

Twenty-eight patients were treated for a failed total knee arthroplasty by arthrodesis with a new type of biplane external fixator. The reasons for failure of the total knee arthroplasty were sepsis in twenty-five patients, loosening in one, pain of unknown etiology in one, and fibrous ankylosis in one. The mean duration of fixation with pins was 112 days. In twenty knees, arthrodesis occurred without further treatment. One knee fused after the application of dual plates, and one united after treatment with electrical stimulation. Of the remaining six patients, one had an above-the-knee amputation for persistent non-union and five had a persistent pseudarthrosis. The extent of loss of bone appeared to be the most important factor influencing union of the primary arthrodesis. One patient who had a solid union of the arthrodesis had a persistent non-union after a fracture at the site of a femoral pin. The rate of success of 68 per cent that was achieved with the device that we used is similar to the rates obtained with the use of older external fixators.