Is cemented metal-polyethylene 22.2mm hip arthroplasty a gold standard? Results of a series of 105 primary arthroplasties at a minimum of ten years follow-up.

INTRODUCTION

Although Charnley-Kerboull metal-on-polyethylene 22.2mm cemented total hip arthroplasty (THA) is considered to be the gold standard in France, results with this prosthesis are conflicting, in particular in relation to Scandinavian registers. The goal of this retrospective study was to confirm the validity of this prosthesis at a minimum of 10years follow-up.

HYPOTHESIS

Survival of this type of THA would fulfill NICE conditions (survival at 10 years of at least 90%).

MATERIALS AND METHODS

One hundred and five primary THA were performed in 93 patients (30 men and 63 women) mean age 72.6 years old (60-86) between January 1998 and March 2001. After a mean follow-up of 10.6 years (10-13 years), 21 patients (23 THA) were lost to follow-up and 32 (35 THA) had died leaving 40 patients (47 THA) for clinical analysis (Merle d'Aubigné and Oxford scores) and X-ray assessment. Survival was calculated with revision for any cause and radiological loosening with or without revision as end-points.

RESULTS

The mean Oxford score at the final follow-up was 22/60 (13-45), the PMA score was 14.2 (11-17). Eight patients underwent revision surgery after a mean 7.5 years (2-11) (1 early dislocation and 7 acetabular cup loosenings). Survival at 10 years was 89.4% (CI95%: 78-95) for all causes of revision and 78% (CI95%: 61-91) for loosening with (n=7) or without (n=3) revision. No cases of septic or femoral loosening were observed. Twelve of the 47 revised hip replacements (25.5%) presented wear≥2mm.

DISCUSSION

Although functional results were acceptable for this elderly population, survival did not reach the NICE value and was lower than results in the literature for this type of implant. Cup loosening and wear were the main causes of revision.

LEVEL OF EVIDENCE IV

retrospective.