Results of Crowe Type IV Developmental Dysplasia of Hip Treated by Subtrochantric Osteotomy and Total Hip Arthroplasty

Background: Crowe type IV developmental dysplasia of hip (DDH), subtrochanteric shortening osteotomy is required to restore the hip joint. Several approaches have been described for subtrochanteric shortening osteotomy. Several osteotomy fixation techniques have been defined for Crowe type IV DDH. This study evaluates the outcomes of subtrochanteric shortening osteotomy fixed with a combination of split onlay autograft and distal fluted femoral stem.

Materials and methods: A retrospective study was carried out on 41 hips of 37 patients treated with total hip replacement for Crowe type IV developmental dysplasia of the hip by subtrochanteric transverse osteotomy and fixed with split intercalary autograft by two cables. A femoral stem with proximal coated and distally fluted was used. The patients were evaluated at a mean of 34 months (range 12-68 months) for union time, leg equalization, and clinical outcomes.

Results: Mean time of union was 13.5 ± 4.6 weeks (range 6-24 weeks). Intraoperative instability of the osteotomy site (n = 16) that was encountered at the trial stage was restored properly by this surgical protocol. Leg length discrepancies were improved to 1.4 ± 0.8 cm (range 0-3 cm). Harris scores were improved from 47.7 ± 10.8 (range 30-68) to 88 ± 5.6 (range 72-98) (P < 0.05) points. There was no nonunion.

Conclusions: Distally well-fitted stem and strengthening of fixation with split intercalary autograft promote additional rotational stability and improve bone union.