Results of the Birmingham Hip Resurfacing dysplasia component in severe acetabular insufficiency: a six- to 9.6-year follow-up.
The dysplasia cup, which was devised as an adjunct to the Birmingham Hip Resurfacing system, has a hydroxyapatite-coated porous surface and two supplementary neutralisation screws to provide stable primary fixation, permit early weight-bearing, and allow incorporation of morcellised autograft without the need for structural bone grafting. A total of 110 consecutive dysplasia resurfacing arthroplasties in 103 patients (55 men and 48 women) performed between 1997 and 2000 was reviewed with a minimum follow-up of six years. The mean age at operation was 47.2 years (21 to 62) and 104 hips (94%) were Crowe grade II or III. During the mean follow-up of 7.8 years (6 to 9.6), three hips (2.7%) were converted to a total hip replacement at a mean of 3.9 years (2 months to 8.1 years), giving a cumulative survival of 95.2% at nine years (95% confidence interval 89 to 100). The revisions were due to a fracture of the femoral neck, a collapse of the femoral head and a deep infection. There was no aseptic loosening or osteolysis of the acetabular component associated with either of the revisions performed for failure of the femoral component. No patient is awaiting a revision. The median Oxford hip score in 98 patients with surviving hips at the final review was 13 and the 10th and the 90th percentiles were 12 and 23, respectively.
The McMinn Centre, 25 Highfield Road, Edgbaston, Birmingham B15 3DP, UK.
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McMinn
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Daniel
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Ziaee
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Pradhan
D000077:Acetabulum / Q000000981:diagnostic imaging / Q000601:surgery*; D000328:Adult; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006618:Hip Dislocation, Congenital / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000209:etiology; D011474:Prosthesis Design; D011859:Radiography; D012720:Severity of Illness Index; D016019:Survival Analysis; D016896:Treatment Outcome