Long-Term Results of an Uncemented Straight Femoral Shaft Prosthesis

Abstract

The first consecutive series of 250 implantations of an uncemented, proximally anchored straight femoral shaft prosthesis in 236 patients is included in this prospective follow-up study. Average time of follow-up evaluation was 11.8 years (range 10.6 - 13.7 years). At follow-up, 41 patients with 44 hips had died and three could not be located. Eight hips were revised, two for infection, one for recurrent dislocation, two for rapid subsidence due to component undersizing and one for aseptic loosening of a varus-malaligned stem; two radiologically well-fixed stems were revised during acetabular revision. Survival estimate showed an overall survival of 96.6% after 14 years (confidence limits: 98.4% (upper) and 92.8% (lower)). The median Harris hip score at time of follow-up was 81.4 points; clinical results were compromised by high loosening rates (68.8%) of the threaded cup, which had been used in 165 of the 250 cases. Radiologically, tiny reactive lines (< 2mm) were frequently present in the distal zones of the femoral shaft, but could be found in the proximal anchoring zone in only one case. In conclusion, the long-term follow-up results with this femoral component are encouraging and are comparable to those of modern techniques of cementing in primary total hip arthroplasty.