The anterior cruciate ligament or ACL, as it is more commonly referred to, is one of four ligaments in the knee whose function is to stabilize the joint. Two of these ligaments — the MCL and the LCL — stabilize the sides of the knee, while a third ligament — called the PCL — works with the ACL to prevent the knee from sliding front to back and back to front. These four ligaments (thick bands of tissue) function sort of like sentries to keep the knee’s movement in one plane.

The main functions of the ACL ligament are keep the lower leg bone (the tibia or shin) from moving too far forward in relation to the thigh bone (the femur), and to limit the rotational movements of the knee. (Besides being a “hinge”, the knee also rotates somewhat as it bends and straightens.)

ACL Injuries

You often hear of ACL injuries in relation to sports that involve jumping (like basketball, volleyball, or gymnastics), sudden stops (like football), or changes in direction (like downhill skiing). Many athletes who suffer an ACL injury report hearing a “pop” at the moment the injury (usually a tear) occurs. Once the ACL is torn or otherwise injured, the knee may swell and feel unstable, as though it might “give out”. It may also be extremely painful, making it difficult to put any weight on the injured leg. Further complicating matters, at least half of all ACL injuries are accompanied by other soft tissue injuries in the knee.

The ACL injury is technically a sprain, but there are different degrees of severity:

  • If the ligament is stretched, but no fibers are actually torn, it’s known as a first-degree sprain.
  • If the ligament is partially torn, it’s a second-degree sprain.
  • If the ligament is completely torn, it’s known as a third-degree sprain.

Interestingly, most ACL injuries don’t occur from contact. Rather, they usually occur at low-speed and on sudden stops, or from pivoting with your foot firmly planted. That’s not to say that they never happen because of contact. Plenty of football players will attest to the fact that a tackle is what caused their ACL injuries, and any gymnast knows that landing incorrectly while dismounting from a balance beam or the uneven parallel bars can cause an ACL injury as well!

Surgery for a Torn ACL

Sometimes a minor ACL injury is treated with rest and physical therapy alone, but for those with ACL tears who expect to return to an active lifestyle, surgery is the usual treatment. For athletes — especially young ones — who want to return to their sport, it’s more or less required. If your doctor recommends surgery, she’ll probably not schedule it immediately, since at least a few weeks of “pre-habilitation” via physical therapy is usually required to strengthen the muscles surrounding the knee. Waiting a few weeks also decreases the risk for excess scar tissue developing around the knee following surgery, a condition that can itself restrict knee motion.

Arthroscopic surgery is the most common surgery used to repair a torn ACL. Because of its blood supply and other technical considerations, the surgeon does not simply sew the torn ligament back together. Instead, he places a graft using tissue from the patient’s own body (a piece of hamstring or patellar tendon) to reconstruct the ACL. The graft acts as “scaffolding” or a base on which new ligament tissue can grow.

Recovering from ACL Surgery

Recovery takes time, and at first (for the first several weeks), the patient needs to take care not to tear the graft. The focus is on slowly restoring the knee to be able to extend and flex to 90 degrees. Usually by week 6 following surgery, the patient can begin strengthening exercises for the surrounding muscles, a program that is designed and supervised by a trained physical therapist. Complete healing takes time, often requiring a physical therapy program that takes from 4 to 6 months to complete.

If you’ve suffered an ACL tear and have had (or will soon have) surgery to repair the injury in the Northeastern Pennsylvania area, Cawley Physical Therapy and Rehab has 5 convenient locations and a staff of top-notch doctors of physical therapy ready to help you through your recovery! Give us a call at (570)208-2787 or send us an email at cawleyptfrank@gmail.com today!