17-year follow-up of the rough-blasted threaded Weill cup in uncemented total hip arthroplasty

Introduction

For uncemented hip arthroplasty, various cup designs are available. The threaded Weill acetabular component (Weill cup; Zimmer, Winterthur, Switzerland) has been used for more than 20 years, with poor results of the smooth threaded design. Our study was intended to assess the 17-year outcome of the rough-blasted option of the threaded Weill cup.

Materials and methods

Between 1987 and 1988, a series of 86 rough-blasted threaded Weill cups were implanted in combination with the CLS^® Spotorno stem (Zimmer Ltd, Germany) The patients’ mean age at the time of surgery was 50 years (range 19–67 years). 67 out of 86 hips (78%) were available for a follow-up at a mean of 17 years (range 16–18 years). Radiographs were available from 55 out of 63 unrevised hips (87%) and analyzed for radiolucency and PE wear.

Results

Two out of 86 cups (3%) were revised due to aseptic loosening and another two cups (3%) were awaiting revision for the same reason. Ten patients (10 cups, 12%) were lost to follow-up, and nine patients with nine cups (11%) had deceased without radiographic signs of cup failure. Cup survival with “revision or awaiting revision” as endpoint was 86% (95% CI 75–92%). No deep infections occurred, and no polyethylene insert was exchanged. The Harris hip score was excellent in 37 out of 67 clinically examined hips (55%), good in 18 hips (26%), satisfactory in 5 hips (8%) and moderate or poor in 5 hips (8%) and 2 hips (3%), respectively.

Conclusion

The rough-blasted threaded Weill cup provides a good long-term performance in cementless total hip arthroplasty. The results compare favourably to the smooth threaded cup design.