An ACL tear is an abbreviation for a tear in the anterior cruciate ligament. This is one of the main ligaments in the knee and helps to keep the knee joint strong and stable.

How Does the ACL Get Injured? 
The ligament is usually torn through a sudden twisting movement of the knee or a sudden impact. This is a fairly common injury in a sport like rugby, for example.

Symptoms of An Injured ACL 
A person who has torn their anterior cruciate ligament feels severe pain and experiences swelling in the knee right away. They may even hear a “pop” at the time of the accident at the ligament’s rupture. The knee might not be able to hold the person’s weight, and the person may not be able to straighten the knee out.

A person who believes they have an ACL injury needs to first follow the RICE procedure. They need to immobilise or rest the knee, apply an ice pack to reduce swelling, apply compression and keep the knee elevated. Then, they need to see their doctor.

The treatment depends largely on the extent of the injury. A minor tear or sprain can be treated with prescribed pain killers and rest. The doctor will recommend that the patient use crutches until the pain and swelling are gone. If the ligaments have ruptured, the doctor may recommend ACL reconstruction surgery. The patient may need physical therapy to strengthen their leg muscles before surgery.

Some of these exercises are designed to help the patient fully extend their knee or achieve a 90 degree bend of their knee. The patient should see results within a week to 10 days after beginning the first exercise and about two weeks after beginning the second. Some of the exercises the physical therapist might have the patient perform are:

• Straight leg raises 
• Single leg stands 
• Exercises to strengthen the patients core, such as the dead bug 

The physical therapist may also use an electrical stimulator on the muscles around the knee to keep the them from losing bulk.

ACL Reconstruction Surgery 
If a patient needs reconstructive surgery, the surgeon uses tissue from the patient’s body to repair the torn ligament. This tissue is called an allograft. Since it comes from the patient, there is no risk of rejection.

The patient is usually put under general anaesthesia, and the ligament is repaired through knee arthroscopy. This requires tiny incisions around the knee into which a camera and small instruments are inserted. The torn ligament is removed through one of the small cuts and a larger incision is made to remove the allograft. The surgeon creates tunnels through the bones of the knee and threads the allograft through them. The tissue is then screwed in place.

The surgeon then places the repaired knee in a brace that is worn for as long as a month. During this time, the patient also uses crutches. When the brace is removed, a physical therapist takes the patient through a series of exercises to help strengthen the knee.