A knee replacement is designed to last for many years, but it will not necessarily last for the rest of your life. One of the most common questions people ask before surgery is how long their new joint will last and whether they might need another operation in the future.
The encouraging news is that many knee replacements last 25 years or more. However, longevity varies between individuals, and no surgeon can guarantee exactly how long a particular implant will last.
Your age, activity levels, general health and the type of replacement all contribute to the picture. Understanding these factors can help you make an informed decision about treatment and what to expect in the years ahead.
How long does a knee replacement last?
According to the NHS guide to knee replacement, knee replacements can last for 25 years.
Long-term research provides further context. A 2019 systematic review and meta-analysis, summarised by the National Institute for Health and Care Research (NIHR), found that approximately 82% of total knee replacements and 70% of partial knee replacements lasted for 25 years in the registry data studied. These figures came from historical data from national registries outside the UK, so they should not be treated as a prediction for an individual patient.
These findings suggest that many replacement joints remain in place for decades. However, the lifespan of an implant depends on several factors, and some replacements may need further surgery sooner.
It is also important to understand what researchers mean when they say a replacement has ‘lasted’. Studies often measure whether the implant has needed revision surgery. They do not necessarily tell us whether every patient has been completely free from pain or has had no problems with their knee.
What affects the lifespan of a knee replacement?
There is no single factor that determines how long a knee replacement will last. Several aspects of your health, lifestyle and treatment can influence its longevity.
Age at the time of surgery
Your age can affect the likelihood of needing revision surgery during your lifetime.
Someone who has a knee replacement at a younger age may place more years of demand on the implant than someone who has surgery later in life. Younger patients may also have higher activity levels, although this varies considerably between individuals.
This does not mean that younger people should automatically delay surgery. The decision should take account of pain, mobility, the impact on daily life and the potential benefits and risks of treatment.
Activity levels
Movement is an important part of maintaining health and mobility after knee replacement. However, repeated high-impact activities can place additional demands on an artificial joint.
Your physiotherapist and consultant can advise you about suitable exercise, including activities that help maintain strength without placing unnecessary strain on the replacement.
Walking, prescribed strengthening exercises and other appropriate low-impact activities may form part of your rehabilitation plan. The right level of activity depends on your recovery and individual circumstances.
Implant design and materials
Knee replacements use artificial components, typically made from metal and medical-grade plastic. Different implant designs and materials are available, and the appropriate choice depends on factors such as your anatomy, the condition of your knee and the surgeon’s assessment.
An implant’s design alone cannot guarantee how long it will last. Long-term outcomes depend on a combination of factors, including the implant, the operation and the individual patient.
Our guide to knee implants explained provides more information about the components used in knee replacement surgery.
General health and recovery
Your overall health can influence your recovery and the risks associated with surgery. Following your post-operative instructions, attending follow-up appointments and completing your prescribed rehabilitation can help you recover safely.
These steps cannot guarantee a particular implant lifespan, but they can support recovery and help your clinical team identify problems that need attention.
Do knee replacements need replacing?
Sometimes, yes. However, not everyone who has a knee replacement will need another operation.
A procedure to replace or revise an existing artificial joint is known as revision knee replacement. It may be considered when an implant wears out, loosens, becomes infected or causes persistent problems that require further surgery.
Possible reasons for revision include:
- Wear and tear: The artificial components can wear over time.
- Loosening: An implant may become less securely attached to the surrounding bone.
- Infection: An infection involving the joint can sometimes require further surgery.
- Instability: The knee may feel unstable or fail to function as intended.
- Fracture: A fracture around the implant may require surgical treatment.
The NHS guidance on complications of knee replacement explains that some people experience ongoing pain, stiffness or instability after surgery, and that further treatment may sometimes be needed.
Having pain after knee replacement does not automatically mean that the implant needs replacing. Your symptoms may have other causes, so assessment is important before deciding what to do next.
Revision surgery is often more complex than the original operation. Your specialist will consider the cause of the problem, your general health and the likely benefits and risks before recommending a treatment plan.
What is the lifespan of a hip replacement?
Hip replacements are also designed to last for many years, although their lifespan varies between patients.
The NHS guide to hip replacement explains that a hip replacement can last for at least 15 years.
A major 2019 research review published in The Lancet examined long-term outcomes from hip replacement studies and national registries. Its analysis of national registry data found that around 89% of hip replacements had not needed revision after 15 years. The researchers noted that the findings relied on historical data and could not predict the lifespan of a specific patient’s implant. As with knee replacement, an implant that has not required revision is not necessarily free from pain or other symptoms.
Factors such as age, activity, implant characteristics and general health can all influence the likelihood of further surgery. Your consultant can explain the relevant considerations when discussing hip replacement.
For more detail about implant components, read our guide to hip implants explained.
How can you look after a knee replacement?
There is no guaranteed way to extend the lifespan of an artificial knee, but following your clinical team’s advice can support your recovery and help you manage your joint health.
Useful steps include:
- Follow your rehabilitation plan. Complete your prescribed exercises and build up activity gradually.
- Choose suitable activities. Ask your physiotherapist which exercises are appropriate for your recovery and long-term mobility.
- Attend follow-up appointments. Your clinical team can assess your progress and advise whether further review is needed.
- Seek advice about new symptoms. Persistent or worsening pain, swelling or instability should not be ignored.
- Look after your general health. Follow advice about managing existing health conditions and maintaining an appropriate level of activity.
Do not assume that you need to restrict all physical activity to protect your implant. Movement and exercise are important parts of recovery, but the right activities and intensity will depend on your circumstances.
When should you seek medical advice?
Contact your healthcare team if your replacement knee becomes increasingly painful, swollen or unstable, or if your ability to walk changes significantly.
If you have recently had surgery and develop a high temperature, discharge from the wound or worsening redness, swelling or pain, seek urgent medical advice. These can be signs of a complication.
Severe leg pain and swelling accompanied by chest pain or difficulty breathing require emergency assessment. Call 999 if these symptoms occur.
New symptoms do not necessarily mean your implant has worn out. A clinical assessment can help establish what is causing them and whether further investigations or treatment are needed.
Understanding your long-term options
Knee replacement can provide lasting relief from joint pain for many people, but the lifespan of an artificial joint cannot be predicted precisely. Most total knee replacements in the studies lasted 25 years.
The same principle applies to hip replacement: long-term results are encouraging, but individual outcomes vary.
When considering surgery, ask your consultant about the expected lifespan of the proposed implant, its potential risks, suitable activities after recovery and the possibility of revision surgery in the future.
Understanding your options can help you feel better prepared for the next step. You can explore the information available on our website, speak to our team about your questions, and request a brochure to learn more about the treatment journey.