New Data on Knee Replacement Longevity

Knee replacement surgery has become one of the most common procedures performed in the UK, with nearly 200,000 of them performed in England and Wales alone in 2017, and for good reason – we have an ageing population who still want to stay active for the rest of their life. We know what they do, we’re making technological breakthroughs year upon year, and we know they work – but we’re still a little in the dark when it comes to their longevity, as the procedure is still in its relative infancy and there has been very little data on their long-term effects.

Well, that’s starting to change. And according to a comprehensive study on knee and hip replacement surgery conducted by researchers at the University of Bristol, there’s a lot more life in the replacements than first thought. The study harvested data from Australia, Finland, Denmark, New Zealand, Norway and Sweden – countries which have kept records of procedures over 15 years – and combed the details of over half a million procedures.

Their conclusions: as many as eight out of ten knee replacements and six out of 10 hip replacements last as long as 25 years.

A replacement that doesn’t need replacing?

The findings, which were published in The Lancet, demonstrated that hip and knee replacements are lasting much longer than originally believed. When it came to total knee replacements, the study concluded that 93% of them lasted 15 years, 90% lasted 20 years, and 82% lasted 25 years and over. Interestingly, partial knee replacements don’t last as long: 77% of them lasted 15 years, 72% lasted 20 years, and 70% lasted over 25 years.

According to the research team, these findings can help patients and surgeons decide upon the optimum time for surgery. “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,” said Dr Jonathan Evans, the lead study author and research fellow at Bristol Medical School. “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.”

While UK data wasn’t used in the research – simply because our record of patients does not go back far enough – the research team pointed out that their findings matched results from smaller studies of UK patients.

Good news for new knees

This is a very important development because it could force the medical community to rethink its position on replacement surgery. At present, the way of thinking is to delay the procedure until absolutely necessary, in order to avoid a replacement of the replacement down the line. Therefore, if the initial replacement is capable of holding up for far longer than first thought, it means that hip and knee replacements can be prescribed earlier in life.

And on a personal note, as I’m looking to have my own knee replaced in the next year or so, the thought of my replacement lasting a quarter of a century is great news. And I’m predicting that the replacements we’re putting in with the aid of the MAKO robot – which are better balanced – should last even longer.

For more information on the benefits of robotic-assisted knee replacement surgery, call 0203 195 2443 to arrange a consultation at Mr Jonathan Webb’s London knee clinic.