Medial collateral ligament (MCL) injury

Expert reviewer Elisabeth Morgans, Bupa Physiotherapist
Next review due April 2021

Your medial collateral ligament (MCL) is one of the ligaments inside your knee. It lies on the inner side of your knee joint, connecting your thigh bone (femur) to your shin bone (tibia). Along with the other ligaments in your knee, your MCL provides your knee with stability. Your MCL and your lateral collateral ligament control the sideways movement of your knee.

An image showing the different parts of the knee


An MCL injury can be a partial or a complete tear, or an overstretch of the ligament. Knee ligament injuries are also referred to as sprains. They’re given different grades depending on how severe an injury it is. The MCL is the most commonly injured knee ligament. It often gets injured during sports such as rugby. It’s common to injure one of your cruciate ligaments, or your meniscus, at the same time as your MCL.

What are the signs?

If you’ve injured your medial collateral ligament (MCL) you’ll probably have some pain and stiffness on the inside of your knee. This area may be tender to the touch too. If your injury isn’t too severe, you’ll probably still be able to walk OK. You may have some swelling, but you don’t always get this with an MCL injury. Depending on the severity of your injury, your knee may also feel a little unstable. You may get some bruising in the first few days after your injury.

Why has this happened?

Your medial collateral ligament (MCL) is usually injured by your knee being pushed inwards (towards your other knee). This is often due to a direct blow to the outside of your leg, which can happen during sports such as rugby. You can also injure it by twisting your knee, for instance in skiing, or from repeated stress on your knee – such as in breast stroke. Older people can also injure their MCL as a result of a fall.

Bone icon Looking for physiotherapy?

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

Bone iconLooking for physiotherapy?

Treatments of medial collateral ligament (MCL) injury

You’ll usually need to go to A&E with this kind of injury. You may then be referred to an acute knee clinic, which will organise any investigations and treatment you need.

The treatment you’ll be offered for your medial collateral ligament (MCL) injury will depend on how severe the damage is. The initial treatment will be to control your pain and swelling using the POLICE and HARM self help measures. Details of these can be found on the next tab. Further treatments include knee bracing, physiotherapy, medicines and occasionally, surgery.

You may see an orthopaedic surgeon (a specialist in bone surgery) or a sports medicine professional, such as a sports doctor or a physiotherapist. A physiotherapist is a health professional who specialises in maintaining and improving movement and function. There are different treatments that your doctor or physiotherapist may suggest, and a lot that you can do yourself to help your injury recover.


An image describing the acronym POLICE
An image describing the acronym HARM

At first you should follow the POLICE procedure to manage any type of soft tissue injury to your knee. POLICE stands for Protection, Optimal Loading, Ice, Compression and Elevation.

There are certain things you should not do 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 Heat, Alcohol, Running and Massage.

If you’re having difficulty bearing 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.


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 severe. As well as easing your pain, non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen may help to reduce any inflammation and swelling you have. Always read the patient information that comes with your medicine, and if you have questions, ask your pharmacist or GP for advice.


Making sure you follow any physiotherapy and rehabilitation programme you’re given will be an important part of your recovery. Often, knee bracing and treatment with physiotherapy will be all you need if you have an MCL injury.

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. Your physiotherapist will carefully assess your knee and then plan a programme of rehabilitation exercises to suit your individual needs.


Most people recover from an MCL injury without surgery. However, in some situations, surgery may be the best option to repair the injury to your medial collateral ligament. This is most likely to be the case if:

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

Ask your doctor about the pros and cons of surgery, and how it might help in your own circumstances.

About our health information

At Bupa we produce a wealth of free health information for you and your family. This is because we believe that trustworthy information is essential in helping you make better decisions about your health and wellbeing.

Our information has been awarded the PIF TICK for trustworthy health information. It also complies with the HONcode standard and follows the principles of the The Information Standard.

The Patient Information Forum tick  This website is certified by Health On the Net Foundation. Click to verify.

Learn more about our editorial team and principles >

    • Acute knee injuries. Functional anatomy. Brukner & Khan’s Clinical Sports Medicine (5th ed, online). McGraw-Hill Medical., published 2017
    • Knee ligament injuries. PatientPlus., last checked 15 February 2017
    • Medial collateral ligament injury. BMJ Best Practice., last reviewed February 2018
    • Collateral ligament injuries. OrthoInfo. American Academy of Orthopaedic Surgeons., last reviewed March 2014
    • Medial collateral knee ligament injury. Medscape., updated 31 May 2017
    • Knee pain – assessment. NICE Clinical Knowledge Summaries., last revised, August 2017
    • Sprains and strains. NICE Clinical Knowledge Summaries., last revised March 2016
  • Reviewed by Pippa Coulter, Freelance Health Editor, Bupa Health Content Team, April 2018
    Expert reviewer Elisabeth Morgans, Bupa Physiotherapist
    Next review due April 2021

Did our information help you?

We’d love to hear what you think. Our short survey takes just a few minutes to complete and helps us to keep improving our health information.