The Anterior Cruciate Ligament
The ACL is one of the four major knee ligaments detrimental to the stability of the knee. Tearing the ACL is mostly an injury that will take place during sports and 3 out of 4 ACL tears will take place without contact from another athlete. When you injure your ACL, you might hear a popping noise and you may feel your knee give out, and usually this will be accompanied by severe selling.
The ACL is the primary restraint to forward motion of the tibia (shin). The femur (thigh) sits on top of the tibia and the knee joint allows both to function as a hinge. The ACL prevents the tibia from moving too far forward on the femur and thus causing a buckling of the knee. Once the ACL is torn, it must be reconstructed using tendons from your own knee or from a cadaver from the bone bank.
In the case of a partial tear, the severity of the injury, the symptoms, and the patients desired level of activity will determine is surgery will be required. If a patient is not an athlete , surgery may not be necessary if rehabilitation is successful in stabilizing the knee.
After the ACL is reconstructed, therapy usually begins the next day and typically it will be up to 6 months before return to contact sports is permitted. More routine activities such as driving or walking begin within days to weeks, depending on how the individual progresses in rehabilitation.
Other typical symptoms include:
- Pain with swelling. (If ignored the swelling may subside. However, if you attempt to return to sports, your knee will probably be unstable and you risk causing further damage to the cushioning cartilage of your knee.)
- Loss of full range of motion
- Discomfort while walking
The ACL can be injured in several ways:
- Changing direction rapidly (Pivoting/Cutting Activities)
- Stopping suddenly
- Slowing down while running
- Landing from a jump incorrectly
- Direct contact or collision, such as a football tackle