Anterior cruciate ligament (ACL) injury
Cruciate ligament injury – anterior; ACL tear; ACL injury; Knee injury – anterior cruciate ligament (ACL)
An anterior cruciate ligament injury, or ACL injury, is the over-stretching or tearing of the anterior cruciate ligament (ACL) in the knee. A tear may be partial or complete.
The knee joint is located where the end of the thigh bone (femur) meets the top of the shin bone (tibia).
Four main ligaments connect these two bones:
- Medial collateral ligament (MCL) runs along the inside of the knee. It prevents the knee from bending in.
- Lateral collateral ligament (LCL) runs along the outside of the knee. It prevents the knee from bending out.
- Anterior cruciate ligament (ACL) is in the middle of the knee. It prevents the shin bone from sliding out in front of the thigh bone.
- Posterior cruciate ligament (PCL) works with the ACL. It prevents the shin bone from sliding backwards under the femur.
- Women are more likely to have an ACL tear than men.
An ACL injury can occur if you:
- Get hit very hard on the side of your knee, such as during a football tackle
- Overextending your knee joint
- Quickly stop moving and change direction while running, landing from a jump, or turning
- Basketball, football, soccer, and skiing are common sports linked to ACL tears.
ACL injuries often occur with other injuries. For example, an ACL tear often occurs along with tears to the MCL and the shock-absorbing cartilage in the knee (meniscus).
Most ACL tears occur in the middle of the ligament, or the ligament is pulled off the thigh bone. These injuries form a gap between the torn edges, and do not heal on their own.
When to Contact a Medical Professional
Call your provider right away if you have a serious knee injury.
Get immediate medical attention if the foot is cool and blue after a knee injury. This means that the knee joint may be dislocated, and blood vessels to the foot may be injured. This is a medical emergency.
Symptoms of ACL Injury
- A “popping” sound at the time of injury
- Knee swelling within 6 hours of injury
- Pain, especially when you try to put weight on the injured leg
- Difficulty in continuing with your sport
- Feeling of instability
Those who have only a mild injury may notice that the knee feels unstable or seems to “give way” when using it.
ACL Reconstruction Surgery
Anterior cruciate ligament repair; Knee surgery – ACL; Knee arthroscopy – ACL
ACL reconstruction is surgery to reconstruct the ligament in the center of your knee. The anterior cruciate ligament (ACL) connects your shin bone (tibia) to your thigh bone (femur). A tear of this ligament can cause your knee to give way during physical activity, most often during side-step or crossover movements.
Most people have general anesthesia right before surgery. This means you will be asleep and pain-free. Other kinds of anesthesia, like regional anesthesia or a block, may also be used for this surgery.
The tissue to replace your damaged ACL will come from your own body or from a donor. A donor is a person who has died and chose to give all or part of their body to help others.
Tissue taken from your own body is called an autograft. The two most common places to take tissue from are the knee cap tendon or the hamstring tendon. Your hamstring are the muscles behind your knee.
Tissue taken from a donor is called an allograft.
The procedure is usually performed with the help of knee arthroscopy. With arthroscopy, a tiny camera is inserted into the knee through a small surgical cut. The camera is connected to a video monitor in the operating room. Your surgeon will use the camera to check the ligaments and other tissues of your knee.