The Anterior Cruciate Ligament (ACL): Role, Risks, and Injury Prevention

Structure and Function

Anatomically, the ACL crosses the knee diagonally and, together with the posterior cruciate ligament (PCL), forms a cross. It limits excessive movements by providing an anchoring point between the tibia and the femur. It plays an essential role in activities such as running, jumping, and pivoting movements. An anterior cruciate ligament tear can be painful and significantly disrupt daily life.

Symptoms of an ACL injury

Depending on the type of anterior cruciate ligament injury , symptoms and their intensity can vary. However, the most common symptom of any type of ACL injury is that patients feel severe pain when the injury occurs. This can cause them to stop the activity immediately. A "pop" or cracking sound may also occur, indicating a more severe injury to the ACL.

The inflammation caused by the injury can lead to swelling around the knee within hours.

Mobility is significantly reduced due to pain in the knee.

Patients often describe a sensation of the knee "giving way" when walking or changing directions. This sensation happens because the knee's stabilisation mechanism is damaged. In some cases, it is difficult to put weight on the affected leg.

Depending on the severity of the ACL injury, the symptoms will be more or less pronounced.

Without treatment, an ACL injury can lead to chronic instability, increasing the risk of damage to other knee structures such as the meniscus and articular cartilage. This can lead to the onset of early osteoarthritis. Therefore, it is important to consult a specialist as soon as possible if you have symptoms of an ACL injury.

Causes and Mechanisms of ACL Injury

An anterior cruciate ligament (ACL) rupture usually occurs during activities that involve sudden stops, rapid changes of direction, or a direct impact to the knee, like in contact sports.

Mechanisms of Injury

• Hyperextension: Overextension of the knee beyond its normal capacity
• Excessive Rotation: Twisting of the knee while the foot is fixed on the ground
• Direct Impact: Direct blow to the knee, often seen in sports collisions

Predisposing Factors

Certain factors increase the risk of ACL injury, including anatomical and behavioural considerations.

Risk Factors

• Gender: Women are more likely than men to sustain ACL injuries due to anatomical and hormonal differences.
• Muscle Imbalances: Weakness in the muscles surrounding the knee can increase the risk.
• Sports Practices: Participating in sports that require movements that stress the ACL, such as football, skiing and basketball.

Preventing ACL Injuries

To prevent ACL injuries, strengthening exercises, proprioception training, and appropriate sports technique can help to reduce the stress placed on the ligament.

Prevention Strategies

• Muscle Strengthening: Focus on muscles that stabilise the leg
• Education and Training: Programmes aimed at improving technique and movements during sports activities

By strengthening the stabilising muscles and improving your technique, the risk of ACL injuries can be reduced.

Protecting the ACL is essential to maintaining knee function and to participating in many activities. A thorough understanding of the structure, functions, risks, and prevention strategies can help reduce the risk of ACL injuries.