LONG TERMS RESULTS OF SUBTROCHANTERIC DEROTATIONAL SHORTENING OSTEOTOMY (SDTSO) FOR THE TREATMENT OF CROWE 4 DDH WITH CEMENTED EXETER FEMORAL COMPONENT

Abstract

Introduction: Restoration of an anatomical hip centre frequently requires limb lengthening, which increases the risk of nerve injury in the treatment of Crowe 4 DDH.

Objective: Prospective evaluation of SDTSO with Cemented Exeter Femoral Component.

Material and Methods: 15 female patients (18 hips – 3 bilateral) with a mean age at time of operation of 51 years followed-up for a mean of 77 months (11 to 133). 16 cemented and 2 uncemented acetabular components were implanted. Exeter cemented DDH stems were used in all cases. No patient lost to follow up.

Results: 18 Crowe IV hips. Charnley-D’Aubigne-Postel score for pain, function and range of movement were improved from a mean of 2, 2,3 to 5,4,5 respectively. One osteotomy failed to unite at 14 months and revised successfully. Clinical healing was achieved at a mean of 6 month while radiological at a mean of 9 months. The mean length of the excised segment was 3cm and the mean true limb lengthening was 2cm. 3.5mm DCP plate with unicortical screws was used to reduce the osteotomy, and intramedullary autografting performed in all cases. Mean subsidence was 1mm and no stem was found loose at the latest follow up. No sciatic nerve palsy observed and no dislocation.

Conclusion: Cemented Exeter femoral components perform well in the treatment of Crowe IV DDH with SDTSO. Transverse osteotomy is necessary to achieve derotation and reduction can be maintained with a DCP plate. Intramedulary autografting prevents cement interposition at the osteotomy site.