An anterior cruciate ligament injury is the over-stretching or tearing of the anterior cruciate ligament (ACL) in the knee. A tear might be partial or complete.

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The knee joint is located where the end of the thigh bone (femur) meets the height of the shin bone (tibia).


Four main ligaments affix these 2 bones:

Medial collateral ligament (MCL) runs follow me the within of the knee. It stays clear of the knee native bending in.Lateral collateral ligament (LCL) runs follow me the outside of the knee. It stays clear of the knee indigenous bending out.Anterior cruciate ligament (ACL) is in the center of the knee. It avoids the shin bone native sliding the end in prior of the thigh bone.Posterior cruciate ligament (PCL) works through the ACL. It stays clear of the shin bone from slide backwards under the femur.

Women are an ext likely to have actually an ACL tear 보다 men.


An ACL injury can occur if you:

Get hit really hard ~ above the side of her knee, such as during a football tackleOverextending her knee jointQuickly stop moving and change direction while running, landing indigenous a jump, or turning

Basketball, football, soccer, and also skiing are common sports linked to ACL tears.


ACL injuries regularly occur with other injuries. Because that example, an ACL tear regularly occurs along with tears come the MCL and the shock-absorbing cartilage in the knee (meniscus).

Most ACL tears take place in the center of the ligament, or the ligament is pulled turn off the thigh bone. This injuries form a gap in between the take it edges, and do no heal on your own.


Early symptoms:

A "popping" sound at the moment of injuryPain, particularly when you shot to put weight top top the hurt legDifficulty in proceeding with your sportFeeling that instability

Those who have only a mild injury may notification that the knee feels unstable or appears to "give way" when using it.

First Aid

See your health treatment provider if girlfriend think you have actually an ACL injury. Carry out not play sporting activities or other activities until you have actually seen a provider and have been treated.

Your provider may send you because that an MRI the the knee. This can confirm the diagnosis. The may additionally show other knee injuries.

First assist for one ACL injury might include:

Raising her leg over the level that the heartPutting ice on the kneePain relievers, such as nonsteroid anti-inflammatory drugs (such together ibuprofen)

You likewise may need:

Crutches come walk till the swelling and also pain gain betterBrace to provide your knee part stabilityPhysical treatment to assist improve joint motion and leg strengthSurgery to reconstruct the ACL

Some people can live and duty normally v a torn ACL. However, most people complain the their knee is unstable and also may "give out" with physical activity. Rough knee after ~ ACL tears can lead to additional knee damage. Girlfriend are also less most likely to go back to the exact same level of sporting activities without the ACL.


Do NOT relocate your knee if you have had actually a significant injury.Use a rail to save the knee directly until you watch a doctor.Do NOT go back to play or other activities until you have actually been treated.

When to contact a medical Professional

Call your provider best away if you have actually a serious knee injury.

Get prompt medical fist if the foot is cool and blue after ~ a knee injury. This way that the knee joint may be dislocated, and also blood ship to the foot might be injured. This is a clinical emergency.


Use ideal techniques once playing sports or exercising. Part college sporting activities programs teach athletes how to minimize stress placed on the ACL. This entails a series of warm up exercises and also jumping drills. There space jumping and landing practice that have been presented to minimize ACL injuries.

The usage of knee braces throughout vigorous athletic activity (such together football) is controversial. It has actually not been shown to alleviate the number of knee injuries, however not specifically ACL injuries.

Alternative Names

Cruciate ligament injury - anterior; ACL tear; Knee injury - anterior cruciate ligament (ACL)

Patient Instructions



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