We describe the survival at ten years of 100 femoral components of the Freeman hip prosthesis. It is proximally hydroxyapatite (HA)-coated and was fixed without cement. Radiological assessment identified radiolucent lines (RLLs) and lytic lesions and was used to measure migration.

The criterion of failure was revision or impending revision for aseptic femoral loosening. No femoral components were revised or are awaiting revision for aseptic loosening, giving 100% survival at ten years (95% confidence interval, 95.7 to 100), although 59 were at risk at ten years. Two components were revised for fracture of a ceramic head with damage to the trunnion. Although well fixed in each, for survival analysis we evaluated the hip as if the patient had died.

Twelve acetabular components were revised and at each operation the femoral component was found to be well fixed, was not disturbed and remained in the survival analysis. Three patients were lost to follow-up, and 12 died with well-functioning prostheses. Radiologically, all except one of the components appeared to be well fixed with no RLLs and no lytic lesions at the latest follow-up. The mean vertical migration was 0.4 mm at one year, 0.8 mm at two years and 1.4 mm at ten years. One component had migrated 7.6 mm at ten years (2.1 mm in year 1) and developed RLLs in Gruen zones I and II. The symptoms, however, were only minor and revision was not indicated.

Our study has shown that proximal HA coating gives effective fixation for a femoral component.

We have compared the survival and radiological outcome at ten years after total hip replacement using two techniques for preparing the femoral canal. The same prosthesis was used throughout and all operations were performed by the same surgical team. In technique 1 the canal was over-reamed by 2 mm and in technique 2 it was reamed to the same size as the prosthesis. Technique 1 was performed on 92 patients and technique 2 on 97 patients.

The survival at ten years was 97.2% (90.6 to 99.2) for technique 1 and 98.8% (92.9 to 99.8) for technique 2. Vertical migration was greater in technique 1 (1.8 mm versus 1.0 mm at five years; p = 0.36). There were significantly more lytic lesions and radiolucent lines at five years (p = 0.0061) with technique 1. We conclude that technique 2 is not worse and may produce better long- term results than current teaching suggests.