When to Consider Knee Replacement

Knee pain can change your routine gradually. You take the lift instead of the stairs. Your usual walk gets shorter. Getting out of a chair takes more effort. Eventually, you may start wondering how much longer you should put up with it.

It may be time to consider knee replacement when pain, stiffness or reduced mobility substantially affect your quality of life and suitable non-surgical treatments are no longer helping, or cannot be used.¹

An assessment can help you understand your options. The decision should take account of your symptoms, general health and what you want to get back to doing.

What is knee replacement surgery?

Knee replacement surgery replaces damaged joint surfaces with artificial components, usually made from metal and plastic. The aim is to reduce pain and improve movement.

The most common reason for a knee replacement is knee osteoarthritis. This can damage the cartilage covering the ends of the bones, contributing to pain, stiffness and difficulty moving. Other reasons include rheumatoid arthritis and arthritis following an injury.

Depending on the pattern of damage, your surgeon may discuss a total knee replacement or a partial knee replacement.^{2 3}

Signs it may be time to consider knee replacement

The effect on your everyday life is an important part of the decision. These changes can be reasons to seek a knee assessment.

Knee pain is limiting everyday activities

Walking, shopping, climbing stairs or getting dressed may have become difficult. Perhaps you plan outings around somewhere to sit, or regularly turn down activities you used to enjoy.

When persistent knee pain starts dictating your routine, it is reasonable to discuss further treatment.³

Pain continues at rest or affects your sleep

Arthritic knee pain can occur while sitting or lying down, as well as during activity. Pain that disturbs your sleep is another reason to seek advice.

Tell your clinician when it happens and how often it wakes you. Night pain needs assessment, as there can be causes other than arthritis.^{4 5}

Stiffness and reduced movement are becoming harder to manage

Difficulty bending or straightening your knee can make ordinary movements awkward. Stiffness after sitting, swelling and a reduced range of movement can occur with knee osteoarthritis.

A knee that is progressively becoming bowed or changing alignment also needs assessment. These symptoms can contribute to a discussion about surgery, but do not establish that a replacement is needed.^{4 6}

Non-surgical treatment is no longer giving enough relief

You may have tried physiotherapy, exercise or pain relief. If suitable treatment is no longer helping enough, or cannot be used, and symptoms substantially affect your quality of life, your clinician can discuss a referral. You do not need to try treatments that are inappropriate for you.¹

What treatments can help before knee replacement?

Non-surgical knee pain treatment can help many people manage their symptoms. Your treatment plan may include:

• Tailored exercise and physiotherapy: strengthening the muscles around the knee and maintaining movement.
• Weight management, if appropriate: reducing the load on a painful knee.
• Walking aids: a stick or other support to make getting around easier.
• Pain relief: gels, creams or medicines selected for your health needs.
• Steroid injections in selected cases: these may provide short-term relief or help you take part in exercise.

A clinician or physiotherapist can help you choose activities that suit your knee. Low-impact options may include cycling, swimming or walking within your tolerance.

Discuss medicines and injections with your healthcare professional, particularly if you take other medicines or have existing health conditions.^{7 12}

Is there a right age for knee replacement?

There is no single age at which everyone should have a knee replacement. NICE advises that age alone should not prevent referral for assessment. Being overweight should not automatically prevent referral either.

Suitability for an operation still needs an individual assessment. Your general health, potential benefits and personal risks all matter. For younger patients, the possibility of needing further surgery later in life is also part of the discussion.^{1 8}

What happens during a knee replacement assessment?

An orthopaedic assessment covers your symptoms, medical history and previous treatments. Your surgeon examines your knee's movement, strength, stability and alignment.

X-rays can show the extent and pattern of joint damage. Further tests may sometimes be needed.

Describe the practical impact clearly: how far you can walk, what happens on stairs and which activities you have stopped doing.

The assessment should lead to a discussion of suitable options and their likely benefits and risks.⁴

Total knee replacement or partial knee replacement?

A total knee replacement replaces the damaged joint surfaces at the lower end of the thigh bone and the upper end of the shin bone. The back of the kneecap may also be resurfaced.

A partial knee replacement replaces a more limited area of the joint and may be an option when arthritis affects one compartment of the knee.

The pattern of arthritis and the condition of your knee help determine which procedure is suitable. Partial replacement can offer a shorter recovery for suitable patients, but it is not appropriate for everyone.⁹

What are the benefits and risks of knee replacement?

Knee replacement can improve daily life by reducing arthritic pain and making movement easier. However, some people experience continuing pain, stiffness or difficulty bending their new knee.

Possible complications include:

• Infection in the wound or joint.
• Blood clots in the leg, which can sometimes travel to the lungs.
• Injury to nearby nerves, blood vessels or other tissues.
• Instability or problems with the replacement that may need further treatment.

A replacement can also wear or develop problems over time, sometimes requiring revision surgery. Your surgeon should explain the risks relevant to you and discuss what improvement you can realistically expect.⁸

What should you expect from knee replacement recovery?

Knee replacement recovery takes time. Full recovery can take several months or longer, and progress varies between patients.

You will usually be helped to start moving and walking soon after surgery. Crutches or a walking frame may be needed initially. Physiotherapy and your prescribed exercises help restore strength and movement.

Before choosing surgery, think about support at home, transport and time away from work. Ask your team about returning to driving and your usual activities. Follow their advice, as recovery milestones depend on your operation, health and progress.¹⁰

Questions to ask your knee surgeon

A consultation is your opportunity to understand the options and make an informed decision. Useful questions include:

• What is causing my knee pain?
• Could further non-surgical treatment help?
• Am I suitable for total or partial knee replacement?
• What improvement is realistic for me?
• What are my personal risks?
• What will rehabilitation involve?
• How much help will I need at home?
• When might I return to work and my usual activities?

Bring a list of your medicines and previous treatments. It can also help to write down your main goals, such as walking the dog, managing stairs or returning to a particular hobby.¹¹

Frequently asked questions about knee replacement

Do I need to wait until knee pain is unbearable?

You can seek an assessment when symptoms are affecting your quality of life. This gives you an opportunity to review treatment and discuss the timing of any surgery. An assessment does not commit you to an operation.^{3 11}

Does “bone-on-bone” arthritis automatically mean I need surgery?

Your clinician considers the X-ray alongside your pain, function, previous treatment and general health. An X-ray finding alone does not decide your treatment.^{4 1}

Can physiotherapy help me avoid knee replacement?

Exercise and physiotherapy can help manage symptoms and improve function. Some people can continue managing without surgery; others may still need a replacement if symptoms significantly affect daily life despite suitable treatment.⁷

Discuss your knee pain with John Lynch

If knee pain is affecting your sleep, mobility or everyday activities, a consultation can help you understand the cause and your treatment options.

Book a consultation with John Lynch to discuss your symptoms, review previous treatment and explore the most appropriate next step for you.

When knee pain needs urgent attention

Contact NHS 111 for urgent advice if your knee is very painful, badly swollen, has changed shape or you cannot move it or put weight on it. Redness or heat around the knee with a high temperature or feeling shivery also needs urgent assessment.⁵

This article provides general information. Individual treatment decisions require a clinical assessment.

Clinical sources

1. NICE NG226, Osteoarthritis in over 16s: diagnosis and management, particularly sections 1.3, 1.4 and 1.6
2. NHS, What is a knee replacement?
3. NHS, Why a knee replacement is done
4. American Academy of Orthopaedic Surgeons, Total Knee Replacement
5. NHS, Knee pain
6. NHS, Osteoarthritis symptoms
7. NHS, Alternatives to a knee replacement
8. NHS, Complications of a knee replacement
9. NHS, How a knee replacement is done
10. NHS, Recovering from a knee replacement
11. NICE NG157, Joint replacement (primary): hip, knee and shoulder, section 1.1
12. NHS, Osteoarthritis treatment and support