Comparing Large-Diameter Metal-on-Metal and Ceramic-on-Ceramic Total Hip Replacement

Abstract

Regarding the failure of conventional metal-on-polyethylene total hip replacement (THR) in younger active patients, other bearings have been increasingly used, namely, ceramic-on-ceramic (CoC) and large-diameter metal-on-metal (MoM) THR, with some advantages. The aim of the study was to compare the large-diameter MoM with CoC THR.

Authors retrospectively followed 42 patients (32 hips) with a mean age of 43 years who had a CoC THR and 22 patients (22 hips) with a mean age of 55 years who had MoM THR. The minimum follow-up was 3 years (mean, 3.9 years). The average Harris hip score (HHS) in large-diameter MoM THR was lower (87.59) compared with CoC THR (88.81). Complications were more frequent in large-diameter MoM THR, with four failures: two infections, one pseudotumor, and one acetabular osteolysis, corresponding to a survival rate at 44 months postsurgery of 81.8 %.

In the group of CoC THR, one patient was revised because of a femoral head fracture, two patients reported audible squeaking, and osteolysis was not detected. The survival rate for revision at 47 months postsurgery was 97.6 %. Low rate of failures and absence of osteolysis verified with CoC THR appear to be good predictors of longer survival expected with this bearing.

Considering the MoM bearing, the high number of failures is similar to other series described in the literature with these implants. The high risk and severity of complications associated with this type of implant does not appear to justify their use despite their potential advantages