ACL-skade: Fremre korsbåndskade - Årsaker, symptomer og behandling

What does an anterior cruciate ligament injury mean?

The ACL, or anterior cruciate ligament, is one of the four major ligaments in the knee joint. It crosses the knee diagonally and plays a crucial role in the stability of the knee joint. An anterior cruciate ligament injury occurs when this ligament is stretched, partially torn, or completely torn. The injury is always classified as serious because it affects the passive stability of the knee joint and creates instability in the knee.

Understanding what an ACL injury is means you need to know the anatomy of the knee. The anterior cruciate ligament is located inside the knee joint and connects the thighbone (femur) to the lower leg. Together with the posterior cruciate ligament, which runs in the opposite direction, they form a cross that stabilizes the knee joint forward, backward and in rotation. When the anterior cruciate ligament is injured, the knee loses a significant amount of its stability, especially during rotational movements. Read more about cruciate ligament injury here .

Common causes of ACL injuries

ACL injuries are often caused by sudden movements or traumatic force to the knee. Common causes include rapid changes in direction while running, sudden stops, improper landing after a jump, or direct impact to the knee. These anterior cruciate ligament injuries are particularly common in high-intensity sports such as soccer, handball, and alpine skiing.

Anterior cruciate ligament injuries are more common in women than in men, possibly due to anatomical and hormonal differences. The injury often occurs without contact with another player, usually when the leg is twisted while the foot is fixed on the ground. In some cases, the posterior cruciate ligament can also be injured at the same time, which further worsens the instability of the knee. Please also read about posterior cruciate ligament injury .

How do you recognize symptoms of anterior cruciate ligament injury?

The most common symptoms of an ACL injury include:

• An audible "pop" or the feeling of something breaking in the knee at the time of injury
• Severe pain and inability to continue activity
• Rapid swelling of the knee (hemarthrosis) which often occurs within a few hours
• Reduced mobility in the knee joint
• Feeling of instability, especially when trying to twist or turn the knee

When the anterior cruciate ligament is injured or damaged, the knee can swell significantly. The swelling, which is caused by bleeding into the joint (hemarthrosis), can make it difficult to fully bend or straighten the knee. The acute pain usually subsides after a few days, but the feeling of instability remains. Many people describe it as the knee "giving way" or feeling unsteady, especially when changing direction or going up stairs. Read more about unstable knee .

Diagnosis and treatment options

If you suspect an ACL injury, it is important to seek medical attention immediately. Your doctor may refer you to an orthopedic surgeon for further evaluation. Diagnosis is usually made through a combination of a physical examination and imaging tests such as an MRI.

Treatment for an ACL injury depends on the extent of the injury and the individual needs of the patient. Surgery may be necessary if the injury is severe or if the patient is active in sports. Anterior cruciate ligament injuries that do not require surgery are treated conservatively with physiotherapy and rehabilitation. For those who undergo surgery, extensive rehabilitation is required after surgery.

A cruciate ligament reconstruction is a surgery in which the damaged cruciate ligament is replaced with a new cruciate ligament, usually using a tendon from the patient's own leg. This procedure is usually performed arthroscopically (keyhole surgery) and requires the use of crutches for a limited period afterwards. The goal of the surgery is to restore the stability of the knee and prevent further damage to the meniscus and cartilage. Also read about meniscus injuries that often occur together.

ACL rehabilitation and recovery

Rehabilitation is a central part of treatment regardless of whether the anterior cruciate ligament injury is operated on or not. A well-planned rehabilitation aims to restore the function, strength and stability of the knee joint. After surgery, rehabilitation is particularly important to ensure that the new cruciate ligament is fully integrated and functions properly.

A structured exercise program led by a physiotherapist focuses on:

• Reduce swelling and pain
• Restoring range of motion in the knee
• Strengthen the muscles around the knee, especially the thigh muscle
• Improve balance and coordination
• Gradual return to sports and physical activity

Rehabilitation after an ACL injury takes time, usually 6-12 months before full return to sports is possible. During this period, it is important to follow the training program carefully and not rush back to high-intensity activities before knee function is restored.

How to prevent anterior cruciate ligament injuries

To reduce the risk of ACL injuries, it is recommended:

• Strength training for legs and torso, with a particular focus on hamstrings and quadriceps to balance muscle strength around the knee
• Improved landing technique and movement awareness, especially practicing landing with bent knees
• Balance and coordination exercises that improve body control
• Regular stretching and mobility training, especially for thigh and hip muscles
• Use of shock-absorbing shoes appropriate for the sport in question
• Gradually increase training intensity to give the body time to adapt

Conclusion

An anterior cruciate ligament injury is a serious knee injury that requires careful diagnosis and treatment. With proper care, including surgery if necessary, physical therapy, and the use of supportive devices such as cruciate ligament knee braces, most people can return to their normal activities. However, it is important to follow the rehabilitation plan carefully and be patient during the healing process. Read more about dislocated knees .