When is the right time for a hip or knee replacement?

There are more than 200,000 hip and knee replacements carried out in the UK every year, mostly because of so-called ‘wear and tear’ osteoarthritis, a long-term condition that causes joints to become painful, stiff and difficult to move.

The problem lies in the cartilage, the smooth-cushioning tissue that covers the ends of bones. When this is worn away, pain, stiffness, swelling, or a grinding sensation may kick in. This in turn restricts your movement. 

Why joint replacements last longer these days

Although the symptoms can be managed with painkillers, exercise, losing weight and physiotherapy to begin with, there may come a point where they have such an impact on daily life that surgery is the best option. But when is the right time?

Mr Jonathan Miles, consultant orthopaedic surgeon at the private HCA Wellington Hospital in London advises: "Twenty years ago, doctors may have advised caution about having a hip or knee replacement 'too early' as they feared the joint would wear out in 10 to 15 years, but things have evolved significantly since then. 

"More and more joint replacements are going to last 30 or 40 years or even longer. If you have one put in at 55 or older, it will probably last for the rest of your life."

Miles says joint implants wearing out is becoming less of an issue because surgeons now use better materials, such as ceramic heads for hip replacements (rather than metal ones) or more durable types of plastic. They also have improved sterilisation techniques.

Is there a right age to have a joint replacement?

The average age for a joint replacement operation is between 65 and 70, but there is no set age for the operations to be done.

Miles says: "The oldest patient I’ve operated on was an exceptionally fit and healthy 102-year-old who did very well after having a hip replacement and we regularly do replacement operations on people in their nineties.

"It’s not so much your age we consider, but the state of your overall health and any other medical conditions you may have such as heart disease, and whether you are fit for surgery."

Your health checklist for needing a knee replacement

The tipping point for needing surgery or not comes down to the impact your symptoms are having on your overall quality of life, says Miles.   

Surgery may be the best option for you if painkillers, physiotherapy and exercise have failed to provide relief and you have some of the following symptoms:  

• pain on resting – sitting down or when you are doing nothing 
• pain that standard painkillers such as paracetamol and ibuprofen won’t control and you are needing stronger painkillers such as opioids, which have side-effects 
• pain is interfering with your daily activities and /or your ability to work and socialise   
• pain and lack of mobility is making you depressed 
•  in severe cases you may be unable to straighten your leg, or the shape of your knees is deformed as the leg deviates to one side (this is definitely a sign that you’ll need a knee replacement soon).  

Miles says the threshold for a partial knee replacement (where only the damaged portion of the knee is replaced) is slightly different.

"You might decide you want a partial knee replacement because you can only manage short walks instead of long ones, for instance, or nine holes of golf instead of 18."

Your health checklist for needing a hip replacement 

These are similar to those for a knee replacement (above) and include:  

• Severe and regular pain in the hip, typically felt in the groin, but can be in the buttock, thigh and sometimes towards the knee
• Stiffness in your hip joint so you find it difficult to put shoes and socks on or to sit for long periods
• Severe and persistent pain, even at rest, affecting your mobility and ability to do daily activities – you may need a walking stick or find it difficult to get out of the bath
• Pain affecting your quality of life by disrupting your sleep, or stopping you socialising or driving
• Failing on conservative management of symptoms such as activity modification, painkillers and physiotherapy  

What is the recovery time after a hip or knee replacement?

The operation can be done under general anaesthetic, sedation or spinal block via an epidural.

"Most people stay only one to three days in hospital after their operation and some younger people are done as day cases," says Miles.

"It will take about six weeks to recover enough to go back to work or resume normal activities. Doing physiotherapy exercises is very important.  

"Knee replacements tend to be more painful than hips at first, as it’s a bigger joint with a richer nerve supply, but you will be given painkillers for this. The average pain score for a knee replacement three weeks after the operation is six out of 10, and three months after it’s still one out of 10.  

"Hip and knee replacements are in the top three for improvements in quality of life, just behind cataracts, so they are worth the short-term discomfort."

How long can you expect to wait on the NHS for a hip or knee replacement?

Figures published in February 2025 revealed there were 49,509 patients waiting for knee replacements on the NHS in England, and the average waiting time was 28.7 weeks (seven months) from the day your appointment is booked through the NHS referral system.

However, Miles, who also works in the NHS, says: "This is an average figure though and a significant number of people are waiting longer than that – sometimes as long as a year or more. Anecdotally, the average wait is more like 40 to 50 weeks."

Is it worth going private?

Your questions answered.

How much do hip and knee replacement operations cost done privately?  

Costs vary geographically and depend on the provider, but you can expect to pay from £12,000 to £18,000. The Practice Plus Group currently charges £12,549; Nuffield Health  £17,960.  

Does private health insurance cover pre-existing conditions?  

Michelle Cooper, director of Saga Health Insurance, advises: "Most health insurance policies don’t cover pre-existing conditions - these are illnesses or injuries you had before taking out the policy. However, some insurers may offer cover if you’ve been symptom-free for a certain period.

"It’s always worth checking with your provider to understand what is and isn’t included."

What if I need time off work for surgery or treatment – can health insurance help?  

"Health insurance is designed to provide fast access to diagnosis and treatment, helping you recover as quickly as possible," explains Cooper.

If your policy includes day patient, in-patient or out-patient cover, you may be able to access private hospital care at a time that suits you, reducing waiting times and minimising disruption to work and daily life. 

If you’re self-employed or managing your own business, this can be particularly valuable, ensuring you get back to work sooner.

What if I need surgery, such as a hip or knee replacement?  

Waiting for surgery can be challenging, especially if you have pain and it stops you from doing what you enjoy.  

"Health insurance means eligible policyholders may be able to access private treatment, including consultations with orthopaedic specialists and faster surgery dates, helping you get back to doing the things you love sooner," says Cooper.  

How does private health insurance support my recovery after treatment?

Recovery is just as important as treatment itself. "Depending on your policy, health insurance may cover follow-up consultations, rehabilitation support such as physiotherapy, and outpatient aftercare to help you get back to full health," says Cooper.

"Whether, you need additional support after surgery or help managing a condition, private healthcare can offer a more personalised approach to recovery."

Can I claim for sports injuries, such as cycling or running-related issues?  

If you suffer an injury from an activity like running or cycling, health insurance may help with access to private physiotherapy, consultant assessments, treatments, and investigations such as scans.  

"The level of cover depends on your policy, so if you’re getting active, it’s always good to know what support is available if you need it," says Cooper.