Researchers from the Musculoskeletal Research Unit at the University of Bristol have found that eight out of 10 total knee replacements and six out of 10 total hip replacements will still be in place after 25 years. The research, funded by the National Joint Registry and the National Institute for Health Research was published in The Lancet in February.
After reviewing thousands of case studies going back 25 years across six countries, generalisable survival data is now available for the first time to estimate how long hip and knee replacements are likely to last.
“Over two million hip and knee replacements have been performed in the UK since 2003, and patients often ask clinicians how long their hip or knee replacement will last; but until now we have not had a generalisable answer,” said lead author Dr Jonathan Evans, National Joint Registry Research Fellow and Clinical Research Fellow at the Bristol Medical School’s Translational Health Sciences department.
“Previous studies have been based on much smaller samples. At best, the NHS has only been able to say how long replacements are designed to last, rather than referring to actual evidence from multiple patients’ experiences of joint replacement surgery. Given the improvement in technology and techniques in the past 25 years, we expect that hip or knee replacements put in today may last even longer.”
Hip and knee replacements are two of the most common and effective forms of surgery. Yet, even in the best-case scenarios, they will ultimately fail due to processes such as infection, fracture, normal wear and tear or reaction to wear particles. In many of those cases, patients require revision surgery, which is more prone to failure, associated with poorer function and more expensive than primary surgery.
Knowing how long a hip or knee replacement is likely to last is therefore key for patients, orthopaedic surgeons and commissioners when deciding whether surgery should be done and when. That will become increasingly relevant to more people given the longer life expectancy of a growing population.