Eighty total hip arthroplasties in seventy-four patients who had had
either a spontaneous or a surgical ankylosis (arthrodesis) of the hip were
evaluated at nine to fifteen years (average, 10.4 years) after the total
hip replacement. There was only one failure in the twenty hips of the
fifteen patients who had had a spontaneous ankylosis. In contrast, twenty
(33 per cent) of the sixty hips of the sixty patients who had had a
surgical ankylosis had complications that were associated with the
arthroplasty. Of these twenty hips, mechanical loosening developed in
eleven; infection, in eight; and recurring dislocation, in one. Failure of
the total hip arthroplasty was more common (p less than 0.05) in the
patients who had had a previous surgical attempt at arthrodesis and in the
patients who were fifty years old or less at the time of the arthroplasty.
The risk of failure was not related to the length of time that the hip had
been ankylosed.