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Medial collateral ligament (MCL) injury

Your health expert: Mr Damian McClelland, Trauma and Orthopaedic Consultant and Clinical Director for Musculoskeletal Services at Bupa
Content editor review by Rachael Mayfield-Blake, Freelance Health Editor, May 2023
Next review due May 2026

A medial collateral ligament (MCL) injury is when you damage one of the ligaments inside your knee. The MCL lies on the inner side of your knee joint, and connects your thigh bone (femur) to your shin bone (tibia). An MCL injury can be a partial or a complete tear, a stretched ligament, or a detachment of the ligament from your bone.


An image showing the different parts of the knee

About medial collateral ligament (MCL) injury

Along with the other ligaments in your knee, your MCL keeps your knee stable. Your MCL and your lateral collateral ligament control the sideways movement of your knee.

When the knee ligament is stretched but still intact, this is called an MCL sprain. Sprains are given different grades depending on how severe they are.

An MCL injury is a common knee ligament injury, and often happens during sports such as rugby and skiing. It’s common to injure one of your cruciate ligaments or your meniscus at the same time as your MCL.

Causes of medial collateral ligament (MCL) injury

An MCL injury is usually caused by your knee being pushed inwards, towards your other knee. This can happen if you get a direct blow to the outside of your leg, often during sports such as rugby. You can also injure your MCL by twisting your knee, for instance while skiing. And from repeated stress on your knee, for instance while swimming breast stroke. You can also injure your MCL if you fall.

Symptoms of medial collateral ligament injury

If you’ve injured your MCL, you’ll probably have some pain on the inside of your knee. This area may be tender to the touch too.

Depending on how severe your injury is, your knee may feel unstable and like it may give way. If your injury isn’t too severe, you’ll probably still be able to walk on it.

You may have some swelling, but you don’t always get this with an MCL injury. And you may get some bruising – it can take one to three days after your injury for this to appear.

Self-help for medial collateral ligament injury

It’s a good idea to follow the POLICE procedure after an MCL injury. POLICE stands for the following.

Protect. Protect your injury from further damage. Rest immediately after the injury but not for long. Consider using some form of support or crutches.

Optimal Loading. Get active sooner rather than later. Start to put weight on your knee and build up your range of movement. Do this gradually – be guided by what feels right for you.

Ice. Place a cold compress such as a bag of ice or frozen peas wrapped in a towel onto your knee. Do this for around 20 minutes every couple of hours for the first two to three days.

Compression. Compress your knee using a bandage to help reduce swelling.

Elevation. Elevate your knee above the level of your heart to reduce swelling. Sit or lie on a chair and use a cushion to raise your leg.

Infographic: POLICE principles

Bupa's POLICE infographic (PDF, 0.5 MB), illustrates the ‘POLICE principles’ to reduce your pain and help you to recover. Click on the POLICE image below to download the PDF.


An image describing the acronym POLICE

And there are certain things you should avoid in the first three days after your injury so you don’t damage your knee further. These can be remembered as HARM, which stands for the following.

Heat. Don’t have hot baths, showers or saunas, and avoid heat packs and rubs.

Alcohol. Drinking alcohol can slow down your recovery and mask your symptoms – increasing the risk that you’ll injure yourself again.

Running. Don’t run or do any other form of moderate exercise.

Massage. Massaging the affected areas can cause more swelling and damage, so avoid this for the first day or two.

Infographic: HARM principle

Bupa's HARM infographic (PDF, 0.6 MB), illustrates the ‘HARM principle' of things you should avoid doing in the first three days after your injury. Click on the HARM image below to download the PDF.


An image describing the acronym HARM

Both POLICE and HARM are measures you can use to treat any type of soft tissue injury to your knee, not just an MCL injury.

If you’re finding it difficult to put weight on your knee, you may need to use crutches or wear a brace to support you for a while. It’s common to wear a leg brace for several weeks after an MCL injury, particularly if your injury is severe. Your doctor or physiotherapist will explain how long you’ll need to use this for.

Treatments for medial collateral ligament (MCL) injury

If you’re worried that you've injured your knee, contact a medical professional who can examine it for you. They may suggest you have an X-ray of your knee. They may refer you to an acute knee clinic, which will organise investigations such as an MRI scan, and any further treatment you may need.

Your MCL injury treatment will depend on how severe the damage is. The first priority is to control your pain and swelling using the POLICE and HARM self-help measures (see our above section on self-help). Other treatments may include knee bracing, physiotherapy , medicines and, occasionally, surgery.

You may see an orthopaedic surgeon (a doctor who specialises in bone surgery) or a sports medicine professional such as a sports doctor or a physiotherapist. There are different MCL injury treatments that your doctor or physiotherapist may suggest, and a lot that you can do yourself to help your recovery.

Medicines for medial collateral ligament injury

You can take over-the-counter painkillers such as paracetamol or ibuprofen to help relieve your pain. Your doctor may prescribe stronger painkillers if your pain is more severe. As well as easing your pain, non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen may help to reduce any inflammation and swelling.

Always read the patient information that comes with your medicine, and if you have questions, ask a pharmacist or GP for advice.

Physiotherapy for medial collateral ligament injury

A physiotherapist will carefully assess your knee and plan a programme of rehabilitation exercises to suit your individual needs. The aim of physiotherapy is to help your knee recover its full range of movement, and its strength and stability. This should help you get full function back in your knee and return to your usual sports and activities. Make sure you do the exercises because they will be an important part of your MCL injury recovery. Often, knee bracing and treatment with physiotherapy will be all you need if you have an MCL sprain.

Surgery for medial collateral ligament injury

Most people recover from an MCL injury without needing to have surgery. But sometimes, surgery is the best option to repair an injury to the medial collateral ligament. This is most likely if:

  • more than one ligament or tissue in your knee is damaged
  • your knee remains unstable after physiotherapy

Looking for physiotherapy?

You can access a range of treatments on a pay as you go basis, including physiotherapy.

To book or to make an enquiry, call us on 0370 218 6528

How long it takes a medial collateral ligament to heal depends on how severe your injury is. If you have a mild sprain, your MCL will usually recover after about 2 to 3 weeks. Then you can return to your normal activities, including sports. If you have a severe sprain, you can return to your activities after about 4 weeks. If you have a severe injury and have torn your ligament, it can take 6 to 12 weeks to recover.

You’ll usually be able to walk with a torn MCL but it depends how severe your injury is. If you’re finding it difficult to put weight on your knee, you may need to use crutches or wear a brace to support you for a while.

For more information, see our section on self-help for medial collateral ligament injury.

You’ll know if you have an MCL injury if you have some pain and tenderness on the inside of your knee. Depending on how severe your injury is, your knee may also feel a unstable and like it may give way. You may have some swelling and bruising too.

For more information, see our section on symptoms of medial collateral ligament injury.

If you have a mild MCL injury and just a few fibres are damaged or torn, it will usually heal on its own. If you have a more severe injury, you may need some treatment to help it heal. For example, if your ligament is completely torn, you may need to have an operation to repair it.

For more information, see our section on treatment of medial collateral ligament injury.

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This information was published by Bupa's Health Content Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals and deemed accurate on the date of review. Photos are only for illustrative purposes and do not reflect every presentation of a condition.

Any information about a treatment or procedure is generic, and does not necessarily describe that treatment or procedure as delivered by Bupa or its associated providers.

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