Sports Medicine Orthopedist
Anterior Cruciate Ligament or ACL injuries are becoming increasingly more common among young athletes. An estimated 200,000 ACL related injuries occur each year. The incidence is significantly higher in student athletes who participate in high-risk sports such as basketball, soccer, football, and skiing.
The ACL is one of four main ligaments in the knee and it runs diagonally in the middle of the knee from the femur to the tibia. The main function of the ACL is to provide anterior and rotational stability about the knee. Over half of injuries to the ACL occur in conjunction with damage to the meniscus, articular cartilage, or other ligaments in the knee.
Approximately 70 percent of injuries to the ACL are the result of a non-contact twisting mechanism while the remaining 30 percent are the result of direct contact. The mechanism of injury is often associated with cutting/pivoting maneuvers coupled with deceleration, awkward landings, or “out of control” play.
Immediately following an acute ACL injury, patients experience pain, swelling, and often an audible “pop”. Several hours later, patients will have a large amount of knee swelling, loss of range of motion, and difficulty walking.
Initial evaluation of a patient with a possible ACL injury includes detailed history, physical examination, and X-rays of the involved knee. If the suspicion for an ACL injury is high, a magnetic resonance imaging (MRI) scan may be ordered to evaluate the ACL and check for additional injury to other structures in the knee.
After a diagnosis is confirmed, non-surgical versus surgical treatment must be discussed. Non-surgical treatment includes progressive physical therapy and rehabilitation with education on how to prevent further instability. A hinged knee brace may also be used for further knee support. However, many people who choose non-operative management may experience repetitive instability episodes leading to further damage to the knee.
Patients who plan to return to high-level activities that involve jumping, cutting, or twisting are usually advised to pursue surgical treatment. Repairing the ACL with sutures has been shown to fail over time; therefore, a substitute graft made of tendon usually replaces the torn ACL. The tendon graft can be taken from the patient’s own tissue, autograft, or donated tissue from a cadaver, allograft. Graft choice is often made depending on both the patient and surgeon preference.
Post-operatively, physical therapy begins just a few days after surgery and is a crucial part to successful ACL surgery. Initially, emphasis is placed on regaining range of motion and decreasing swelling about the knee. Therapy progresses to strengthening of the quadriceps and hamstrings muscles while restoring the sense of balance and neuromuscular control. A patient may return to sports when there is no pain or swelling, full range of motion has been achieved, and when muscle strength and endurance have been restored.