Purpose of the study: This was an analysis of long-term outcome of 260 consecutive total hip arthroplasty (THA) procedures performed with a press-fit CLS-Spotorno cup. This easy-to-position cup preserves bone stock if revision should be needed.

Material and methods: From January 1990 to December 1994, 260 THA were implanted with a CLS-Spotorno cup in 221 patients. The clinical and radiological outcome was assessed with minimal ten years follow-up. Mean age at operation was 63 years (range 26–82 years). Sixty eight patients (68 hips) died before ten years follow-up. Five patients (five hips) could not be transported for review and four patients (four hips) were lost to follow-up. This study thus concerned 183 Spotorno cups (70.3%) in 144 patients (65.1%) who were reviewed clinically at 120–166 months follow-up. One hundred twenty-five patients agreed to undergo a radiological work-up. X-rays were analyzed by several independent operators. Two hundred sixty prostheses were implanted by two senior surgeons using the transgluteal approach. The Harris score and the De-Lee-Charnley radiological assessment as well as the Kaplan-Meier survival curve were determined.

Results: Seven cups were revised (3.8%): three because of aseptic loosening, two during stem revision because of polyethylene wear, and two for recurrent dislocation. Radiographically, four cups (2.2%) had migrated and there was a lucent line adjacent to the cup in at least one of the three De-Lee-Charnley zones for 23 cups (12.5%). There were no cup wing fractures. The mean Harris score for 144 patients (183 hips) was 90 points (range 37–100) at last follow-up. Outcome was considered excellent for 123 hips (67%), good for 34 (18.5%), fair for 20 and mediocre for five. The Kaplan-Meier 10-year survival with revision as the end point was 99% (CI: 94.8–99.8%).

Discussion: The 10-year survival of CLS-Spotorno cups is excellent with a low rate of revision. These results can be tempered by the radiological findings, although the lucent lines were already visible on the 12-month x-rays with no visible progression.

Conclusion: This cup provides excellent long-term results with a survival curve comparable to other press-fit cups. It is easy to position and revise.