A total of 47 non-walking patients (52 hips) with severe cerebral palsy and with a mean age of 14 years, (9 to 27) underwent a Dega-type pelvic osteotomy after closure of the triradiate cartilage, together with a derotation varus-shortening femoral osteotomy and soft-tissue correction for hip displacement which caused pain and/or difficulties in sitting. The mean follow-up was 48 months (12 to 153). The migration percentage improved from a pre-operative mean of 70% (26% to 100%) to 10% (0% to 100%) post-operatively. In five hips the post-operative migration percentage was greater than 25%, which was associated with continuing pain in two patients. Three patients had persistent hip pain and a migration percentage less than 25%. In five hips a fracture through the acetabulum occurred, and in another there was avascular necrosis of the superior acetabular segment, but these had no adverse effect on functional outcome. We conclude that it is possible to perform a satisfactory pelvic osteotomy of this type in these patients after the triradiate cartilage has been closed.
Proximal femoral varus osteotomy improves the
biomechanics of the hip and can stimulate normal acetabular development
in a dysplastic hip. Medial closing wedge osteotomy remains the
most popular technique, but is associated with shortening of the
ipsilateral femur. We produced a trigonometric formula which may be used pre-operatively
to predict the resultant leg length discrepancy (LLD). We retrospectively
examined the influence of the choice of angle in a closing wedge
femoral osteotomy on LLD in 120 patients (135 osteotomies, 53% male,
mean age six years, (3 to 21), 96% caucasian) over a 15-year period
(1998 to 2013). A total of 16 of these patients were excluded due
to under or over varus correction. The patients were divided into
three age groups: paediatric (<
10 years), adolescent (10 to
16 years) and adult (>
16 years). When using the same saw blades
as in this series, the results indicated that for each 10° of angle
of resection the resultant LLD equates approximately to multiples
of 4 mm, 8 mm and 12 mm in the three age groups, respectively. Statistical testing of the 59 patients who had a complete set
of pre- and post-operative standing long leg radiographs, revealed
a Pearson’s correlation coefficient for predicted This study identified a geometric model that provided satisfactory
accuracy when using specific saw blades of known thicknesses for
this formula to be used in clinical practice. Cite this article:
