Background: Reorientation of the acetabulum
may be necessary in the treatment of an unstable hip in children
with developmental dysplasia of the hip. In 1961, Salter described
the innominate osteotomy for stabilizing the reduced hip in the
position of function by redirection of the acetabulum as one piece.
In the present study, we describe our long-term results with this
Methods: We reviewed the cases of sixty-one patients
who had seventy-three Salter innominate osteotomies. At the time
of the operation, the mean age of the patients was 4.1 years (range,
1.3 to 8.8 years). Radiographs made preoperatively, postoperatively, and
at the time of the most recent follow-up visit were evaluated. Clinical
evaluation was performed with use of the Merle d’Aubigné and
Postel system as well as the Harris hip score.
Results: The mean duration of follow-up was 30.9
years (range, 26.2 to 35.4 years). There were seven true revisions
(one acetabuloplasty, one triple osteotomy, and five total hip arthroplasties).
With true revision as the end point, the cumulative survival rate
at 35.3 years was 0.90. Fifteen of the seventy-three hips were considered
a failure, which was defined as a revision or a Harris hip score
of <70 points and/or a Merle d’Aubigné and
Postel score of <13 points. The long-term clinical outcome
was significantly influenced by the grade of dislocation on the
radiographs made at the first examination (p = 0.0388)
and on those made immediately preoperatively (p < 0.0001),
the postoperative summarized hip factor (the radiographic grade
of dysplasia) (p = 0.0002), the preoperative (p = 0.0392)
and postoperative (p = 0.0072) grades of avascular necrosis
of the femoral head, and the technique of reduction (p < 0.0001).
Conclusions: When an acetabulum can be most closely
restored to a normal configuration without the development of avascular necrosis,
good long-term results (lasting for more than thirty years) can
be expected. When open reduction is necessary, it is preferable
to perform it separately prior to the Salter innominate osteotomy.
The grade of dislocation at the time of the first examination and
immediately preoperatively, the grade of avascular necrosis of the
femoral head, and the adequacy of surgical correction are important
prognostic factors for the long-term clinical result.