Bilateral valgus-extension osteotomy of hip using hybrid external fixator in spondyloepiphyseal dysplasia: Early results of a salvage procedure

The treatment of spondyloepiphyseal dysplasia (SED) congenita patients with severe bilateral hip involvement is difficult because it involves deformities of multiple joints and of the spine. The purpose of this study was to evaluate the results of the procedure described below as a method of treatment for bilateral hip involvement in SED congenita patients. We performed proximal femoral valgus-extension osteotomy with distal femoral varus osteotomy using a hybrid external fixator in eight patients (seven male patients and one female patient) or 16 hips. The patients had a mean age of 16.37 years (range, 9-25 years) at the time of surgery. The mean valgus angle at the proximal osteotomy site was 53.4° on the right side and 52.5° on the left side, and the mean varus angle at the distal osteotomy site was 22°. Mean fixator time was 19.8 weeks (range, 10-42 weeks). After an average follow-up of 25.9 months, the mean modified Harris hip score had improved from 67.9 points to 79.1 points, which was statistically significant (P=0.012). Preoperative knee range of motion was achieved at the last follow-up in all patients. Waddling gait was absent in three patients, reduced in four patients, and was the same in one at the last follow-up. Mean limb length gain was 3.5 cm (range, 0-5 cm), mean limb length discrepancy less than 0.5 cm, and the mechanical axis was realigned in all. In conclusion, our early results suggest that proximal valgus-extension osteotomy with distal femoral varusization can be a useful treatment option in young patients with bilateral hip involvement in SED congenita.