What is the most effective type of hip implant combination for patients undergoing a hip replacement?

Researchers from
the Bristol Medical School at the University of Bristol 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 1960s.

The National
Institute for Health Research (NIHR)-funded research (published today 3 Nov)
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 77 randomised controlled trials and analysed data from 3,177 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.”

Paper

‘Choice of implant combinations in total hip replacement: systematic review and networkmeta-analysis’ by López-López J, Humphriss R, Beswick A, Thom H, Hunt L,Burston A, Fawsitt C, Hollingworth W, Higgins J, Welton N, Blom A, and Marques E in BMJ