Anterior Cruciate Ligament Injury


What is an anterior cruciate ligament (ACL) injury? An ACL injury is a partial or complete tear of the ACL. The ACL is a ligament in your knee that connects the tibia (shin bone) to the femur (thigh bone). Ligaments are strong tissues that connect bones together. The ACL stops the tibia from sliding too far forward and keeps the knee stable.

What causes an anterior cruciate ligament injury? Trauma such as from a car accident or a fall may cause a tear in the ACL. An ACL injury may happen when the outer or inner side of the knee gets hit hard. This often happens in contact sports, such as football, basketball, and hockey. You may also injure your ACL by twisting your knee while you are standing, overextending your knee, or suddenly stopping or changing direction while you are running.

What are the signs and symptoms of an ACL injury?

How is an ACL injury diagnosed? Healthcare providers may test the function of your ACL by moving your knee, leg, or foot in different directions. You may be asked to lean or hop using your leg with the injured knee. Tell your healthcare provider if you feel pain while you do these or other activities. Both of your knees may be checked for any abnormal movement. You may need the following tests:

How is an ACL injury treated?

How can I manage my anterior cruciate ligament injury?

When should I seek immediate care?

When should I contact my healthcare provider?


You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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