In an analysis of motor function, ambulatory function, and hip stability
in sixty-five patients with myelodysplasia, four motor-function groups
based on the strength of the quadriceps and hip abductor muscles were
identified. Retrospectively, it was evident that based on these groups, it
would have been possible to predict which hips would remain stable, what
level of ambulatory function the patients could achieve, and whether
treatment to reduce and stabilize the hips was indicated. Fifty-seven of
fifty-eight hips in the twenty-nine patients with functioning quadriceps
muscles but non-functioning hip-abductor muscles were either subluxated or
dislocated. Thirty-nine of the remaining forty-six patients with
functioning quadriceps muscles could walk. In this series, three operative
procedures were used to treat hip subluxation: varus osteotomy, varus
osteotomy combined with iliopsoas transfer, and iliopsoas transfer alone.
One shelf procedure was also done. Varus osteotomy was the best procedure
for hip subluxation while posterior iliopsoas transfer, either alone or in
combination with a varus osteotomy, was of questionable value. Treatment of
hip instability (subluxation or dislocation) in patients without quadriceps
function was not necessary.