Knee replacement
Knee replacement surgery replaces damaged joint surfaces with artificial components. It is most commonly used for advanced knee osteoarthritis when pain, stiffness and loss of function are having a substantial impact on everyday life.
A treatment for severe knee pain and loss of function
- Most commonly performed for advanced knee osteoarthritis
- Usually considered after appropriate non-surgical treatment
- Damaged joint surfaces are replaced with artificial components
- Rehabilitation begins early and continues after discharge
What is a knee replacement?
Knee replacement is an operation in which damaged areas of the knee joint are resurfaced and replaced with artificial components.
In a total knee replacement, the damaged surfaces at the lower end of the thigh bone and upper end of the shin bone are prepared and covered with prosthetic components. A specialised plastic spacer sits between them to allow the new joint surfaces to move against one another.
The operation is most often performed for osteoarthritis when pain, stiffness and loss of mobility have become substantial. Depending on the pattern of arthritis, some patients may instead be suitable for a partial knee replacement, which is covered separately on this website.
The decision to proceed should take account of symptoms, daily function, general health, previous treatment and personal goals. Imaging supports the decision but should not determine it in isolation.
The expected benefits, alternatives, limitations and individual risks should all be discussed before surgery is chosen.
When might knee replacement be considered?
Knee replacement may become appropriate when arthritis symptoms are substantially affecting quality of life and suitable non-surgical treatments are no longer providing enough benefit.
Reasons to consider surgery
- Persistent knee pain despite appropriate non-surgical treatment
- Increasing stiffness or loss of movement
- Walking distance has become substantially limited
- Stairs and everyday tasks are increasingly difficult
- Pain is regularly affecting sleep
- Symptoms are having a major effect on independence or quality of life
Alternatives before surgery
A range of non-surgical treatments may still be appropriate depending on the severity and pattern of symptoms.
- Therapeutic exercise and strengthening
- Activity modification
- Weight management where appropriate
- Suitable pain-relieving medication
- Walking aids where helpful
- Selected injection treatment in appropriate circumstances
What does knee replacement involve?
The exact procedure is planned around your anatomy, the pattern of arthritis and the type of implant considered appropriate.
Preparing the thigh bone
Damaged surfaces at the lower end of the femur are carefully prepared and covered by a shaped metal component.
Preparing the shin bone
The damaged surface at the top of the tibia is prepared and fitted with a component that supports the new bearing surface.
Restoring movement
A durable plastic bearing sits between the metal components. The aim is to create a stable joint with useful movement and alignment.
From consultation to recovery
Assessment and shared decision-making
Your symptoms, examination, imaging, previous treatments, health and priorities are considered before an operation is recommended.
Preparing for surgery
Preoperative assessment checks your general health and provides advice on exercise, medicines and practical preparation for the recovery period.
Surgery and hospital care
The damaged joint surfaces are replaced. Pain relief, blood-clot prevention, wound care and early mobilisation form part of postoperative treatment.
Rehabilitation and return to activity
Walking and exercises begin early. Movement, strength and confidence are then progressively rebuilt over the following weeks and months.
What knee replacement aims to achieve
The main aim is to reduce pain caused by the damaged knee joint. Improvements in movement and function can then help restore useful everyday activity.
- Reduced knee pain
- Improved walking and mobility
- Greater ability to manage stairs and daily tasks
- Improved sleep where night pain has been a problem
- Improved independence and quality of life
Knee replacement cannot guarantee a completely pain-free joint, unrestricted movement or a return to every previous activity.
Important risks to understand
Knee replacement is major surgery. The likelihood of individual complications varies according to general health, anatomy and other personal factors.
- Infection
- Blood clots in the leg or lungs
- Bleeding or wound problems
- Persistent pain or stiffness
- Nerve, blood vessel or tissue injury
- Instability or problems with movement
- Wear or loosening of the components over time
- Need for further or revision surgery
Rehabilitation is an important part of knee replacement
Recovery is gradual. Early movement helps restore independence, while knee movement, muscle strength, walking tolerance and confidence continue to improve after leaving hospital.
Getting safely mobile
Rehabilitation begins early after surgery. You will be encouraged to stand and walk with appropriate support and begin exercises for movement and strength.
Regaining everyday function
Home exercises and progressive activity help restore knee movement and muscle strength. Walking aids are reduced when it is safe to do so.
Returning to normal activity
Progress continues over several months. Return to driving, work and exercise depends on individual recovery and the advice of your surgical team.
Preparation starts before the operation
Preoperative assessment checks that surgery can proceed as safely as possible and gives you the opportunity to understand what to expect before, during and after the operation.
Maintaining movement and strength before surgery, improving general health where possible and preparing practical support at home can make the early recovery period easier to manage.
- Continue suitable strengthening and mobility exercises
- Stop smoking where possible
- Maintain a balanced diet
- Work towards a healthier weight where appropriate
- Follow instructions about medicines before surgery
- Arrange practical help and prepare the home for recovery
Questions about knee replacement
How do I know when it is time for a knee replacement?
There is no single age, X-ray result or pain score that determines the right time. Surgery is generally considered when pain, stiffness and reduced function are substantially affecting quality of life and appropriate non-surgical options are ineffective or unsuitable.
What is the difference between total and partial knee replacement?
A total knee replacement resurfaces the main compartments of the knee, while a partial knee replacement treats only the part affected by arthritis. Partial replacement is suitable only for selected patterns of disease and is covered on a separate treatment page.
How long does knee replacement surgery take?
The NHS advises that knee replacement surgery commonly takes around one to two hours, although the exact duration varies with the operation and individual circumstances.
How long does recovery take?
Recovery continues over several months. Many people leave hospital within a few days when their wound is satisfactory and they are safely mobile, but movement, strength and endurance continue to improve after discharge.
Can I have a second opinion about knee replacement?
Yes. A second-opinion consultation can review your symptoms, X-rays, previous treatments and the proposed operation, including whether total or partial knee replacement may be appropriate.
Discuss whether knee replacement may be appropriate for you
A consultation with Mr Dowen can review your symptoms and imaging, discuss alternatives to surgery and explain whether total or partial knee replacement may be suitable.