Introduction: Cementless acetabular components have been associated with a higher rate of pelvic osteolysis compared to cemented components. Modular locking mechanisms and wear against screw heads and holes have been implicated in the production of polyethylene particles. Pressure waves and particle access to the pelvis are facilitated by screw holes. The patients in this study had a cementless, modular cup with screw fixation but not in all holes. Therefore factors thought to contribute to osteolysis were present.

Methods: 178 consecutive patients (198 hips) underwent primary THA using the EPF cementless cup (Plus Orthopaedics AG, Switzerland). 30 patients (31 hips) had died, 5 hips were revised, 8 were lost to follow up and 9 were unable to attend for radiographs. 126 patients (145 hips) were followed up clinically (Harris Hip Score) and radiographically. Mean follow up was 8.0 years (6.3–9.4). AP, lateral and Judet view radiographs were analysed for osteolysis. Polyethylene wear rates were determined using a validated 2D method (Martell).

Results: The mean HHS was 89.0 (44.4–99.9). Osteolysis was seen in 19 hips (13.1%). In only 6 hips (4.1%) osteolysis was evident on the AP radiograph. In 13 hips (9.0%) osteolysis was only seen on lateral or Judet view radiographs. No cups were considered to be loose. Mean linear polyethylene wear rate was 0.10 +/− 0.06 mm/yr. Mean volumetric polyethylene wear rate was 43.2 +/− 28.2 mm³/yr. There was no significant difference between wear rates in hips with osteolysis compared to no osteolysis. Only 1 revision was for aseptic loosening.

Discussion: The EPF cup produced good clinical results, and appeared radiologically stable at 8 years. Wear rates are similar to other studies of cementless cups. The osteolysis rate is low given this “worst case scenario” especially considering the increased likelihood of detecting osteolysis with multiple radiographic views.

We describe the clinical and radiological results of 120 consecutive revision hip replacements in 107 patients, using the JRI Furlong hydroxyapatite-ceramic-coated femoral component. The mean age of the patients at operation was 71 years (36 to 92) and the mean length of follow-up 8.0 years (5.0 to 12.4). We included patients on whom previous revision hip surgery had taken place. The patients were independently reviewed and scored using the Harris hip score, the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and the Charnley modification of the Merle d’Aubigné and Postel score. Radiographs were assessed by three reviewers for the formation of new bone, osteolysis, osseointegration and radiolucent lines in each Gruen zone.

The mean Harris hip score was 85.8 (42 to 100) at the latest post-operative review. The mean WOMAC and Merle d’Aubigné and Postel scores were 34.5 and 14.8, respectively. The mean visual analogue score for pain (possible range 0 to 10) was 1.2 overall, but 0.5 specifically for mid-thigh pain. There were no revisions of the femoral component for aseptic loosening. There were four re-revisions, three for infection and one for recurrent dislocation. Radiological review of all the femoral components, including the four re-revisions showed stable bony ingrowth and no new radiolucent lines in any zone. Using revision or impending revision for aseptic loosening as an end-point, the cumulative survival of the femoral component at ten years was 100% (95% confidence interval 94 to 100). We present excellent medium- to long-term clinical, radiological and survivorship results with the fully hydroxyapatite-ceramic-coated femoral component in revision hip surgery.

Removal of well-fixed, cementless, acetabular components during revision arthroplasty remains a challenging problem. Further damage to host bone may limit options for reconstruction and compromise the long-term result of the revision operation. We report the results of 31 hips with well-fixed, cementless sockets which were removed using a new cup extraction system. In all hips the socket was removed without difficulty and with minimal further bone loss.