Limited comparative evidence shows no advantage of metal on metal, ceramic on ceramic bearings
WEDNESDAY, Nov. 30 (HealthDay News) -- Implantable hip devices with metal on metal or ceramic on ceramic bearings do not offer an advantage over those with traditional bearings, according to a review published online Nov. 29 in BMJ.
Art Sedrakyan, M.D., Ph.D., from Weill Cornell Medical College in New York City, and colleagues compared the safety and effectiveness of combinations of bearing surfaces of hip implants through a systematic review of clinical trials, observational studies, reports of major registries, and summaries for pre-market application and mandated post-market studies. Qualitative data syntheses were carried out on 18 comparative studies, including 3,139 patients (mean age, 42 to 71 years; 26 to 88 percent women) and 3,404 hips; and more than 830,000 operations from national registries.
The investigators found that patients receiving metal on polyethylene bearings had similar or better disease-specific functional outcomes and general quality of life scores, compared with those receiving metal on metal bearings in trials. One clinical study reported fewer dislocations with metal on metal implants. Higher rates of implant revision were seen with metal on metal implants versus metal on polyethylene implants in the three largest national registries. Fewer implant revisions were reported for ceramic on ceramic, compared with metal on polyethylene implants in one trial, but not in any of the national registries.
"Results do not indicate any advantage for metal on metal or ceramic on ceramic implants compared with traditional metal on polyethylene or ceramic on polyethylene bearings," the authors write.