Metal-on-metal total hip joint replacement: a minimum follow-up of five years.

UNLABELLED: The search for an ideal bearing surface for hip arthroplasty is ongoing. Over 1000 metal-on-metal total hip replacements have been performed at our institution since 1993. A review of 215 primary hip arthroplasties performed using Metasul (Sulzer, Winterthur, Switzerland) metal-on-metal articulation with a minimum follow-up of five years is presented. Six patients were lost to follow-up, leaving 209 hips for review. The average follow-up was 7.33 years (range 5-11.4 years). The mean preoperative Harris Hip Score (HHS) was 39.8 and mean postoperative hip scores rose to 89.5, 87.3, 88.4 and 85.8 at 1-year, 3-year, 5-year and final follow-up respectively. Two hips were revised for acetabular loosening and none due to loosening of the femoral stem. Implant survivorship was 95.5% at 12 years. No untoward systemic effects were noted in the cohort. Metasul metal-on-metal articulation has shown satisfactory results in the medium term with regard to osteolysis and aseptic loosening.

LEVEL OF EVIDENCE: IV (Case series).