Anterior cruciate ligament injury
What is it?
The anterior cruciate ligament (ACL) is one of the ligaments in your knee and runs from the outside of the back of your thigh bone to the inside of the front (anterior) of your shin bone. It helps to stabilise the knee. It's often damaged by twisting or overextending the knee, especially during sports.
Symptoms
The symptoms of anterior cruciate ligament injury include:
- widespread pain around the front, sides and back of your knee
- swelling of your knee joint
- instability – you may feel like your knee is giving way or that it's locking
- limited movement of your knee
- bruising around your knee after injury
You may feel a popping or snapping sensation at the time of the injury, or even hear a popping sound. You may also find that you can't stand properly on the affected leg, or put your full weight on it.
Causes
You may injure your anterior cruciate ligament by:
- landing awkwardly from a jump
- twisting movements, particularly when your foot is on the ground
- quickly changing direction when running or walking
- slowing down suddenly when walking or running
Occasionally you may injure your anterior cruciate ligament if you hit your knee.
Treatment
You should seek treatment from a sports medicine professional, such as a sports medicine doctor or a physiotherapist. The treatment for anterior cruciate ligament injury will depend on what damage you have done and how bad the damage is.
Medicines
You can buy painkillers such as paracetamol or ibuprofen to treat mild and moderate pain. Your GP or sports medicine doctor may prescribe stronger painkillers if your pain is severe. As well as easing your pain, painkillers may help to reduce inflammation and swelling. Always read the patient information that comes with your medicine, and if you have questions ask your pharmacist or doctor for advice.
Physiotherapy
If your injury is moderate to severe you will often need physiotherapy. Your physiotherapist will develop a programme of rehabilitation exercises gradually to strengthen your knee and stretch your muscles. Strengthening and balance exercises will be very important in your rehabilitation. Braces to support your knee are occasionally used during rehabilitation, usually if the injury has been severe.
Surgery
In some situations, you may need to have surgery to repair the injury to your anterior cruciate ligament. This is likely if:
- you do a lot of sport
- more than one ligament or tissue in your knee has been damaged
- your knee remains unstable after physiotherapy
Do
- Follow PRICE.
Don't
- There are certain things that you shouldn't do in the first three days after your injury to prevent further damage to your knee - these can be remembered as HARM.
Peer reviewed by Alex Floyd, MCSP, Bupa Sports Medicine physiotherapist
Publication date: June 2009
