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.