This important joint is held together by these four ligaments, which connect bones to one another:

Its main function is to prevent Hyperextension, state where the angle between the body parts or joints is really high. ACL also has a secondary function to restrain tibial rotation and varus/valgus stress.

Causes

Anterior Circulate Ligament Tears or injuries usually occur during sports or fitness activities, when the following happens:

Sudden Slowing and changing direction

Pivoting with foot firmly placed

Sudden slowing or stopping while running

Incorrect landing during a jump

Direct hit to the knee during a collision or tackle

Two wheeler accidents is another common cause of Anterior Circulate Ligament tears in Indian sub-continent.

Symptoms

The patient will have the following symptoms:

Loud ‘popping’ sound from the knee and it giving out from under you

Severe pain and inability to continue activity

Swelling that begins within 24 hours. Might get resolved on its own but will return if the same activity is restarted.

Loss of range of motion

Joint Line’s tenderness

Discomfort while walking

If you experience any of the above symptoms while playing or exercising, then:

DO NOT move your knee

Use a splint to keep the knee straight till medical help arrives

DO NOT return to playing or exercising or running.

Diagnosis And Treatment

In a physical examination, the doctor will check the injured knee for swelling and tenderness, comparing it with the uninjured one. The injured ligament will be subjected to clinical test and integrity will be assessed, and overall function of the knee will be tested.

The following tests will help in confirming the diagnosis:

X-rays to get a clear image of the bones to rule out a fracture but it can’t visualize ligaments and tendons.

Magnetic Resonance Imaging (MRI) to see the extent of the Anterior Circulate Ligament tear injury and damage to other tissues of the knees.

Prevention

Some measures to be taken to prevent ACL tears are:

Wear the right footwear for the sport and the surface its being played on.

Strengthen and the stretch the major leg muscles: hamstrings, quadriceps and calf muscles.

Learning the right technique for the movement you going to perform like turning, jumping and stopping correctly.

In some cases, using of knee braces also helps.

Warming up before playing will prevent injuries.