Most hip and knee replacements will last for 25 years or more, patients can now be reassured.
A first-of-its-kind study has looked at how long joint replacements lasted in more than 200,000 people in more than six countries.
Eight out of 10 total knee replacements and six out of 10 total hip replacements will still work properly after 25 years, findings published in the Lancet show.
It will ease the minds of many patients who may fear more surgery down the line because of the risk of infection, fracture or wear and tear.
Surgeons will also have a better idea of the best time to conduct the surgery in an ageing population.
Hip and knee replacements last for 25 years or more, experts are now able to tell millions of patients due to findings from a study at the University of Bristol
‘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, based at Southmead Hospital in Bristol.
‘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 last 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.
Until now, the NHS has only said hip joints are designed to last for 15 years or more – but now doctors may be able to give their patients more concrete hope.
The aim is long-term relief of pain and restoration of function, often for sufferers of osteoarthritis, which affects around a third of people aged over 45 in the UK.
But knee and hip replacements fail for a variety of reasons, including loosening, infection, persistent pain, and instability.
In around 10 per cent of hip replacements, the new joint can feel unstable and loose, and in three per cent of cases, the hip joint can come out of its socket while the hip is healing, according to the NHS.
Frustratingly, many patients end up needing more surgery and revision over the joint’s lifetime, which may only worsen their problem.
The authors of the study, led by the University of Bristol, said: ‘In the UK, in 2016, the typical patient requiring knee replacement was aged 69 years.
‘Given enough time, all knee replacements will fail and need to be revised. Revision is expensive and results in worse outcomes than primary surgery.’
Planning when a surgery takes place is becoming increasingly relevant as people live longer.
The study involved the reports of a total of 215,676 people whose cases were followed up for 15 years after undergoing total hip replacements; 74,052 who were followed up for 20 years; and 51,359 who were followed up for 25 years.
The data came from Australia, Denmark, Finland, New Zealand, Norway and Sweden – countries which hold more than 15 years’ worth of figures.
The findings of the study, funded by the National Joint Registry, from the Musculoskeletal Research Unit at the University of Bristol, show that of the total hip replacements, 89 per cent were found to last 15 years.
After 20 years, 70 per cent had lasted, and 58 per cent lasted 25 years.
Of knee replacements, up to 93 per cent were found to last 15 years, 90 per cent lasted 20 years and 82 per cent lasted 25 years.
The figures were slightly lower for unicondylar knee replacements (UKR), which only replace the damaged part of the knee, compared to total knee replacements (TKR), which replace all the natural joint surface.
A total of 77 per cent of UKRs were found to last 15 years, 72 per cent lasted 20 years, and 70 per cent were seen to last 25 years.
There is considerable variation in how long different designs of hip and knee replacements last – including the materials used and how they are fixed – and these factors were accounted for in the study.
The only other option for the incurable degenerative joint disease osteoarthritis is medication to alleviate symptoms, leaving up to 8.75million people crippled in pain, according to Arthritis Research UK.