Abstract
Introduction
Debate continues regarding the relative advantages of ceramic-on-ceramic (CoC) and metal-on-polyethylene (MoP) articulations in total hip arthroplasty (THA). Perceived benefits of CoC include longevity, and low wear - in turn limiting the effects of particulate wear debris. However, CoC bearings cost significantly more, and concern remains over the risk of ceramic fracture; a complication not seen with MoP bearings, which are also cheaper.
Method
We electronically randomised 268 consecutive patients undergoing THA to receive either a CoC or MoP articulation. Patients aged over 72 were excluded. In all patients the prosthesis used was an uncemented ABG II (Stryker, USA), implanted by one of the two senior authors (HDA, ABM). Patients were scored preoperatively, and at annual follow-up clinics, using SF36, Visual Analogue (VAS), Merle d'Aubigné (MD) and Oxford Hip (OHS) Scores. Satisfaction levels were also documented.
Results
Follow-up ranged from 4–10 years (mean 73.9 months). 56 patients died or were lost to follow-up, leaving 212 (79.1%); 102 CoC and 110 MoP respectively. There was no statistical difference in age, follow-up, pre-operative scoring, surgeon numbers of each prosthesis or sex distribution between groups.
5 CoC patients underwent revision surgery, compared with 4 MoP. Mean follow-up scores in the CoC group were: SF36 67.9, VAS 1.5, MD 16.5 and OHS 28.2, for the MoP cohort, results were: SF36 61.1, VAS 2.4, MD 16.3 and OHS 21.8. None of these were statistically significant differences, and satisfaction levels were the same between groups.
Discussion
Our data suggest that, up to 10 years, both articulations give equal satisfaction, survivorship and functional outcomes. Anecdotally, many surgeons appear increasingly to favour ceramic bearings in THA; although longer follow-up may be needed to demonstrate any advantages of ceramic over MoP, results such as ours should perhaps be considered when making this decision.
