Abstract
Introduction: Hip arthroplasty for dysplasia of the hip provides a challenge to all hip surgeons. The choice of prosthesis used depends on the severity of the deformity, and the challenge of acetabular reconstruction. We report a review of 105 of our cases operated since 1992 with a minimum two-year follow-up.
Methods: The data in this study has been collected and entered prospectively since 1992 on an arthroplasty database. A total of 105 cases were identified and reviewed. The indication for surgery was painful hip osteoarthritis secondary to dysplasia. All patients were reconstructed with some attempt at restoration of the hip centre, and without femoral osteotomy.
Results: There were 96 patients (10 bilateral), 66 females and 29 males whose mean age at surgery was 53 years (23 to 97 years). The mean follow-up period was 59 months (27 to 107 months). The hip was exposed via a posterior approach in 98% of cases. The majority (94%) of cases had no previous surgery. Depending on the degree of dysplasia either an ABG or S-ROM prosthesis was used.
There were 78 Crowe I & II, and 18 Crowe III & IV hips. The more dysplastic hips required the versatility of the SROM stems to avoid excessive lengthening or femoral osteotomy. These cases also had significantly more inferior reconstruction of the hip centre, and medialisation of the hip centre.
Complications occurred in 8/106 (8%) of cases, the mean time to occurrence being 25 months. The majority were dislocations 7 (7%). There were no sciatic nerve palsies. Revision was required for 5 cups and 1 stem. Clinical evaluation showed all patients were living at home and 85% had no activity restrictions. Mean Harris Hip Score was 92/100. None or mild thigh pain only was reported in 90% of cases. In 98% of cases patients were satisfied with their outcome. Radiographic evaluation showed stem ingrowth occurred in all cases. Minor osteolysis was apparent in 6% of cases. Spot welds were identified in 76% of cases. One case demonstrated pedestal formation.
Conclusion: Reconstructing hip joint mechanics is a challenge in the dysplastic hip. The use of different prostheses for the varying severity in dysplasia has been an effective approach to optimise hip mechanics. Our results using this approach with cementless implants has given excellent short term clinical and radiographic results.
The abstracts were prepared by Professor Jegan Krishnan. Correspondence should be addressed to him at the Flinders Medical Centre, Bedford Park 5047, Australia.
