Researchers from the Bristol Medical School have found that there is no evidence that any of the newer hip implant combinations, such as ceramic or uncemented, are better than the widely used small head metal on plastic cemented hip combination, which has been commonly used since the sixties.

The University of Bristol reports that the National Institute for Health Research (NIHR) funded research also confirms previous knowledge from observational evidence that resurfacing hip replacements and metal on metal implants fail more than the metal on plastic small head cemented implants.

The research team reviewed seventy seven randomised controlled trials and analysed data from three thousand one hundred and seventy seven hip replacements to estimate which implants fail less in total hip replacement surgery. Hip replacement implants can have different materials such as metal on plastic, ceramic on plastic, ceramic on ceramic, or metal on metal, with large or small head sizes, and can be fixed to the bone with or without cement.

The research paper, published in BMJ, is the most comprehensive review of all the available information to date, and the analysis excluded low-quality studies.

Dr Elsa Marques, Research Fellow in the Musculoskeletal Research Unit at the Bristol Medical School: Translational Health Sciences, who led the study, said “Around 30 per cent of the total hip replacements in the UK use the traditional metal-on-plastic, small head, cemented implants. Our trials review also confirms observational findings from joint patient registry data, suggesting that national registries are a good source of real-world evidence for patients who are considering a total hip replacement. This study is reassuring to patients that there is no evidence to show that the newer hip material combinations are superior to the traditional hip replacement implants.”