Anterior Cruciate Ligament Tears

The anterior cruciate  ligament (ACL) is one of the four major ligaments in the knee joint. It plays a critical role in maintaining stability and preventing excessive knee joint movement.

It is a strong, fibrous band of tissue that connects the femur (thigh bone) to the tibia (shin bone) in the knee joint. It controls the forward movement and rotation of the shin bone, which is essential to the ability to walk, jump, and run. Tears can be painful and debilitating, making engaging in any physical activity, including sports and daily life, difficult.

The symptoms of an ACL tear can vary but typically include:

• A sudden “popping” sound or sensation in the knee at the time of injury.
• Severe pain when attempting to stand or put weight on the affected leg.
• Rapid swelling usually develops within a few hours.
• Instability or a feeling that the knee is giving way or shifting on itself.
• Reduced range of motion, making it difficult to fully bend or straighten the knee.

• Non-Contact Sports Injuries: ACL tears are generally associated with activities that place a high demand on the knee joint. The risk of an anterior cruciate ligament (ACL) injury is very high among athletes involved in jumping, pivoting, and rapid change of direction. Athletes who play basketball, soccer, and football have the highest incidence of ACL injuries.

• Improper landing techniques after a jump can result in excessive strain on the knee, leading to a tear. Non-contact ACL injuries represent more than half of all ACL injuries sustained in team-ball sports.

• Trauma: Direct impacts to the knee, such as those in contact sports like football, a fall, or a motor vehicle accident, can also cause ACL injuries.

• Another common cause is overextension of the knee joint beyond its normal range of motion, which can occur in a sport like skiing.

• Gender: Female athletes are at greater risk of ACL injuries compared to males. Female athletes experience the highest rate of non-contact ACL injuries due to differences in anatomy, hormones, and biomechanics.

Diagnosing an ACL tear typically involves a combination of physical examinations and imaging tests. During a physical examination, Dr. Waterman will check for swelling, tenderness, and range of motion and may perform specific tests, such as the Lachman test or the pivot shift test, to assess knee stability.

Magnetic resonance imaging (MRI) is necessary to provide detailed images of the soft tissues in the knee to confirm an ACL tear and identify any associated injuries. X-rays are used to rule out bone fractures that might have occurred along with ligament injury.

Treatment options for an ACL tear depend on the severity of the injury, the patient’s activity level, and overall health.

• Non-surgical treatment is appropriate for patients with stable partial tears and lower activity levels or those not involved in high-demand sports. Treatments include rest, ice, compression, and elevation (RICE) to reduce pain and swelling, a structured rehabilitation plan to restore strength and flexibility, and a knee brace to provide additional support and prevent further injury.

• In some carefully selected cases of partial or complete ACL tears, ACL repair may be performed to reattach the ligament to the bone. This may be recommended for pediatric and adolescent patients with specific injury patterns or tears on the ACL’s top (proximal) or distal (ends).

• For complete ACL tears, particularly in athletes or active individuals, surgery is recommended. ACL reconstruction involves using a tendon graft from the patient’s body (autograft) or a donor (allograft) to replace the torn ligament. It is recommended for athletes and individuals who seek to return to high-demand activities. ACL reconstruction is minimally invasive arthroscopic surgery. In high-risk individuals, graft tissue may also be reinforced with synthetic taped sutures or another form of knee stabilization called lateral extra-articular reconstruction (i.e., iliotibial band tenodesis). After surgery, a knee brace is necessary to support and protect the graft during healing.

A tailored rehabilitation plan is essential for a successful recovery. Six to twelve months after surgery, a carefully monitored return to sports activities is recommended.