Anterior Cruciate Ligament Tear (ACL Tear)
An ACL injury involves tearing the anterior cruciate ligament in your knee. This crucial ligament frequently ruptures during sports requiring abrupt stops, jumps, or directional changes – like basketball, soccer, football, tennis, skiing, volleyball, and gymnastics.
Many people report a “pop” sensation in the knee when an ACL tear occurs. Afterward, the knee often swells, feels unstable, and is too painful to bear weight.
Treatment depends on the injury’s severity. For minor ACL tears, options include resting the knee, as well as physical therapy exercises to regain strength and stability. For partial or complete ACL ruptures, surgery to reconstruct the torn ligament followed by physical therapy is often recommended.
Symptoms of ACL injury
Signs and symptoms of an ACL injury usually include:
A loud “pop” or a “popping” sensation in the knee
Severe pain and inability to continue activity
Swelling that begins within a few hours
Loss of range of motion
A feeling of instability when weight bearing
Causes of ACL injury
Ligaments are strong bands of tissue that connect one bone to another. The ACL, one of two ligaments that cross in the middle of the knee, connects your thighbone (femur) to your shinbone (tibia) and helps stabilize your knee joint.
Most ACL injuries happen during sports and fitness activities that can put stress on the knee:
Suddenly slowing down and changing direction (cutting)
Pivoting with your foot firmly planted
Landing from a jump incorrectly
Stopping suddenly
Receiving a direct blow to the knee or collision, such as a football tackle
When the ligament is damaged, there is usually a partial or complete tear across the tissue. A mild injury may overextend the ligament but leave it intact.
Risk factors for ACL injury
Women are more likely to have an ACL injury than men who participate in the same sports. Studies have suggested some reasons for these differences in risk.
In general, women athletes exhibit a strength imbalance in their thighs with the muscles at the front of the thigh (quadriceps) being stronger than the muscles at the back (hamstrings). The hamstrings help prevent the shinbone from moving too far forward — a movement that can overextend the ACL.
Studies comparing jumping and landing techniques among men and women athletes have shown that women athletes are more likely to land from a jump in a way that increases stress on their knees.
Research suggests that training to strengthen muscles of the legs, hips, and lower torso — as well as training to improve jumping and landing techniques — may reduce the higher ACL injury risk associated with women athletes.
Complications of ACL injury
People who experience an ACL injury are at higher risk of developing knee osteoarthritis, in which joint cartilage deteriorates and its smooth surface roughens. Arthritis may occur even if you have surgery to reconstruct the ligament.
Multiple factors likely influence the risk of arthritis, such as the severity of the original injury, the presence of related injuries in the knee joint or the level of activity after treatment.
Prevention of ACL injury
You can lower your chance of an ACL injury through proper training and exercise. A physical therapist, athletic trainer or sports medicine specialist can assess, educate and provide feedback to reduce your risk. Effective programs include:
Strengthening leg muscles, especially hamstrings, to balance leg strength
Core exercises for hips, pelvis, and lower abdomen
Technique training for proper jumping, landing, pivoting, and cutting motions
Supportive gear
Footwear and padding suited for your sport can help prevent injury. If you ski downhill, ensure bindings are properly adjusted by a professional for optimal release.
Wearing a knee brace does not appear to prevent initial or recurrent ACL injuries.
When to see a doctor
If you sustain any knee injury that produces signs or symptoms of an ACL injury, seek medical attention right away. The knee is an intricate assembly of bones, ligaments, tendons and other tissues that work in tandem. It’s crucial to secure a timely and precise diagnosis to determine the seriousness of the injury and receive appropriate treatment.
Injured your ACL? It is important to get it checked and treated early to regain function as soon as possible. Schedule a consultation with Dr Sean Leo, orthopaedic surgeon and knee specialist, who can make an assessment and offer appropriate treatment.
