Comparative evidence assessment of implantable hip devices by bearing surface: systematic appraisal of evidence

Journal British Medical Journal
Authors Sedrakyan A; Normand S-L; Dabic S; Jacobs S; Graves S; Marinac-Dabic D
Year Published 2011
Link to Publication

Objective

To determine comparative safety and effectiveness of combinations of bearing surfaces of hip implants.

Design

Systematic review of clinical trials, observational studies, and registries.

Data sources

Medline, Embase, Cochrane Controlled Trials Register, reference lists of articles, annual reports of major registries, summaries of safety and effectiveness for pre-market application and mandated post-market studies at the United States Food and Drug Administration.

Study selection

Criteria for inclusion were comparative studies in adults reporting information for various combinations of bearings (such as metal on metal and ceramic on ceramic). Data search, abstraction, and analyses were independently performed and confirmed by at least two authors. Qualitative data syntheses were performed.

Results

There were 3139 patients and 3404 hips enrolled in 18 comparative studies and over 830 000 operations in national registries. The mean age range in the trials was 42-71, and 26-88% were women. Disease specific functional outcomes and general quality of life scores were no different or they favoured patients receiving metal on polyethylene rather than metal on metal in the trials. While one clinical study reported fewer dislocations associated with metal on metal implants, in the three largest national registries there was evidence of higher rates of implant revision associated with metal on metal implants compared with metal on polyethylene. One trial reported fewer revisions with ceramic on ceramic compared with metal on polyethylene implants, but data from national registries did not support this finding.

Conclusions

There is limited evidence regarding comparative effectiveness of various hip implant bearings. 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.