Revision Hip Surgery Using the Cls Expansion Shell

The aim of our study is to assess the outcomes using the uncemented CLS expansion shell in revision hip surgery for aseptic loosening of the acetabular component.

Between 1991 and 2000 we used the CLS expansion shell in revision hip surgery in 215 patients (230 hips). We were able to evaluate 196 patients (211 hips) with failed acetabular components. The male/female ratio was 82/114 and the mean age of the patients was 63 years (range 38–71). The main reason for revision was aseptic loosening of the PE cup (184 patients). There were 79 hips with Paprosky defect of the acetabulum type I, 62 hips with type 2A, 57 hips with type 2B and 13 hips with type 2C in the study. The mean follow-up was 8.5 years (range 5–14). Plain radiographs using an AP view of the pelvis and AP and lateral views of the affected hip were taken immediately after surgery and at the latest follow-up. Clinical outcomes were determined using the Merlé dAubigné and Postel score and the Harris Hip score.

The mean preoperative Merle dAubigné score was 7.8 points (range 6.9 to 9.9); at the latest follow-up it was 14.9 points (range: 12.5 to 15.9). The mean preoperative Harris Hip score was 38.6 points (range: 32 to 59); at the latest follow-up it was 82.5 points (range: 38 to 95).

Osteointegration of the CLS expansion shell was present in 149 hips (70.6%) at the latest follow-up. There were 31 complications (15%) requiring a second revision. Clinical survivorship of the CLS expansion shell was 90% at five years and 84% at 8.5 years after revision surgery. Radiological survivorship was 78% at five years and 70% at 8.5 years after revision surgery.

The CLS expansion shell offers a viable alternative for revision hip surgery with lower bone quality, insufficient bone at the bottom and cavitary defects of the acetabulum.