"KNEE INJURIES:The Anterior Cruciate Ligament"

Anterior cruciate ligament (ACL) tears are one of the most feared injuries in sports. Athletes and sports fans cringe when they hear that diagnosis because they know that it is, at least, a season-ending injury. In many cases, an ACL injury may mean a permanent change in athletic endeavors. ACL injuries are not uncommon-over 200,000 occur annually in the United States. As many as 75,000 ACL reconstruction surgeries are performed each year. Football, soccer, basketball, skiing, and baseball account for 78% of all sports related ACL tears in the U.S. And females are 3-5 times more likely to injure their ACL than their male counterparts.

What is the ACL?

The ACL is a band of fibrous tissue that provides support to the knee. It is the primary restraint to limit forward movement of the lower leg (tibia) relative to the thigh (femur), and it also helps restrain lower leg rotation (pivoting). The function of the ACL is to stabilize the knee joint, prevent abnormal movements, and help guide the movement of the knee.

What are the signs and symptoms of the injury?

Often a pop is heard or felt at the time of the injury. A sensation of instability or knee buckling, especially with pivoting or jumping, is common, as is rapid swelling of the knee. An inability to fully straighten out the knee and significant pain may be present since 75% of ACL injuries include bone contusions and/or meniscal damage.

What are the causes of the injury?

70-80% of ACL injuries occur in non-contact situations. Usually the athlete is planting and cutting, or landing on one leg. In addition, the foot is firmly planted on the ground and is outside the (vertical plane) of the knee, which is slightly bent or straight.
In contact situations, the knee is usually impacted from the side or front (hyperextension), with the foot firmly planted on the ground and the knee slightly bent or straight.

Can this injury be prevented?

Studies have shown that ACL injuries can be reduced via specific exercises that includes perturbation training, jump landings on two feet with the knee over the toe, and strengthening of the lower extremity muscles. Also by avoiding surfaces and shoes that produce a high amount of friction.

What is the role of physical therapy?

ACL injuries in the adult do not heal themselves. The old ligament cannot be fixed, so a new one needs to be constructed. Whether or not a person decides to have surgery (and 70% of untreated knees develop arthritis and/or meniscal tears within 10 years), all patients will benefit from physical therapy. Decreasing pain and swelling, re-establishing normal range of motion and strength, improving balance, agility, and ambulation skills are essential components of a good physical therapy program.
One of the most important things to consider when deciding about treatment is---how long will recovery take?

At COAST Rehab, patients that have ACL surgery (reconstruction) typically return to all normal activities safely within 2-3 months, and sports activities in 3-5 months, which is 2-6 months earlier than typical physical therapy programs.