[Short-term results of interposition arthroplasty with autologous femur head graft combined with cement-free threaded cups for treatment of dysplastic coxarthrosis].

INTRODUCTION

The operative treatment of arthritis in congenital dysplastic hips (CDH) with an autologous femoral head graft is a well established technique in total joint arthroplasty. This prospective study introduces a new operative technique in which the fixation of the autologous bone graft is achieved through the threaded Zweymueller cup solely. Early results are presented.

METHOD: 34 patients, (average age of 53.2 years, 24 to 74 years) with CDH had a total joint arthroplasty in combination with a femoral head autograft between 1995 and 1997 (32 patients in study). The fixation of the bone graft was achieved with screws or with a press-fit technique through the threaded cup. The results are described with an average of 2 years.

RESULTS

The patients were followed prospectively for an average of 2 years. The Harris hip score increased from 32 preoperatively (range 14-61) to 82 (range 54 to 91) postoperatively. 30 hips had excellent and good results, one satisfactory and one had an unsatisfactory result. Radiographic evaluation demonstrated no osteolysis, one radiolucency was seen in Zone III of the acetabulum and heterotopic bone formation was observed in 11 of 31 radiographically evaluated hips (Brooker type I: 7, type II: 3 and type III: 1). All bone grafts achieved union, all grafts survived, and all acetabular components survived, but one. There were no complications such as dislocation, infection, nerve palsy, or a thrombo-embolic event observed.

CONCLUSION

Fixation of the femoral head autograft in CDH with a threaded cup solely showed no disadvantages over the established fixation technique with screws over a short-term follow-up. A solid stable fixation of the graft with a threaded Zweymueller cup was achieved and resulted in full graft integration without the use of screws.