Femoral and Dega osteotomies in the treatment of habitual hip dislocation in Down syndrome patients - is it efficient or not?

PURPOSE: The purpose of this case series study is to report on the intermediate-term outcomes following a femoral varus derotational osteotomy (FVDO) performed in conjunction with a Dega osteotomy (DO) in management of hip ­instability in Down syndrome (DS) patients. METHODS: Ten hips in seven children with DS suffering from hip dislocation were included. All patients included in this study had hip dislocation in the habitual phase and painless mobile hip to full abduction. All patients were firstly subjected to FVDO. An additional DO was added if intraoperative assessment demonstrated posterior instability. The mean age at time of surgery was 5.6 years (3 to 7). There were three male and four female patients. All patients were followed up after two years with a mean follow-up of 3.27 years (2 to 5). All operations were performed by the first author. RESULTS: There was improvement of neck shaft angles (130° to 175°, median = 160° preoperatively, to 120° to 140°, median =130° postoperatively). The Shenton line was restored in all our cases. There was also improved percentage of the femoral head uncovered by the lateral wall of the acetabulum (25° to 100° with median = 45° preoperatively, to 0° to 15° with median = 5° postoperatively) and improved posterior acetabular coverage, which was assessed by CT. CONCLUSION: FVDO combined with DO without ­capsulorrhaphy is efficient in the management of hip instability in DS, as it corrects hip biomechanics and increases posterior acetabular coverage. LEVEL OF EVIDENCE: IV - retrospective case series