If you tear the anterior cruciate ligament in your knee, you may need to have reconstructive surgery.
The anterior cruciate ligament (ACL) is a tough band of tissue that joins the thigh bone to the shin bone at the knee joint.
It runs diagonally through the inside of the knee and gives the knee joint stability. It also helps to control the back-and-forth movement of the lower leg.
The ACL is the most commonly injured knee ligament. Every year in the UK, there are about 30 ACL injuries for every 100,000 people.
The ACL can be torn if your lower leg extends forwards too much. It can also be torn if your knee and lower leg are twisted. Knee injuries can occur during sports such as skiing, tennis, squash, football and rugby. ACL injuries account for around 40% of all sports injuries. Some common causes of an ACL injury include:
If the ACL is torn, the knee becomes very unstable and loses its full range of movement. This can make it difficult to perform certain movements, such as turning on the spot. Some sports may be impossible to play. Read more about other common sports injuries.
A torn ACL cannot be repaired by stitching it back together. However, it can be reconstructed by grafting (attaching) new tissue onto it.
The ACL can be reconstructed by removing what remains of the torn ligament and replacing it with a tendon from elsewhere, for example hamstrings or patellar tendon.
Read more about how ACL reconstructive surgery is performed.
Reconstructive ACL surgery is successful in about 90% of cases. A few people may still experience knee pain or instability after having the operation.
Recovering from surgery usually takes around six months. However, it could be up to a year before you can fully return to training for your sport.