Eighty hips with unilateral Legg-Calve-Perthes disease were evaluated at
an average follow-up of 22.4 years to determine the long-term results of
treatment by a weight-relieving sling or harness. Results were good in
sixty-four patients, fair in nine, and poor in seven. The patients with
fair results had no clinical symptoms despite unacceptable roentgenograms.
The hips that were most likely to have unsatisfactory results were those
with Catterall Group-III or IV involvement and with onset at the age of six
years or later, but of fifty-eight patients with Catterall Group-III or IV
grades (eighteen of whom were six years old or older), forty-two had good
results. Catterall's classification could not be accurately applied for an
average of 8.1 months after the onset of disease. Identification of
so-called head-at-risk signs, while it was important, appeared to add
little to the Catterall grading as a prognostic index or therapeutic guide.
Thirty-nine hips were identified as being at risk, including six of the
seven with poor results and all of the nine hips with fair results.