Anterior Cruciate Ligament (ACL) Injury
Signs and Symptoms
If you injure your ACL, you may not feel any pain immediately. However, you might hear a popping noise and feel your knee give out from under you. Within 2 to 12 hours, the knee will swell and you will feel pain when you try to stand. Apply ice to control swelling and elevate your knee until you can see an orthopaedic surgeon.
If you walk or run on an injured ACL, you can damage the cushioning cartilage in the knee. For example, you may plant the foot and turn the body to pivot, only to have the shinbone stay in place as the thighbone moves with the body.
A diagnosis of ACL injury is based on a thorough physical examination of the knee. The investigation may include several tests to see if the knee stays in the proper position when pressure is applied from different directions. Your orthopaedist may order an X-ray and MRI (magnetic resonance imaging) or, in some cases, arthroscopic (‘key-hole’) inspection.
A partial tear of the ACL may or may not require surgical treatment. A complete tear is more serious and may require reconstruction, especially in younger athletes.
Both non-operative and operative treatment choices are available for ACL tears, depending on the seriousness of the injury and the patient’s personal circumstances.
- May be used because of a patient's age or overall low activity level;
- May be recommended if the overall stability of the knee seems good;
- Involves a treatment program of muscle strengthening, often with the use of a brace to provide stability.
Operative treatment (either ‘key-hole’ or open surgery):
- Uses a strip of tendon, usually taken from the patient's knee (patellar tendon) or hamstring muscle, which is passed through the inside of the joint and secured to the thighbone and shinbone;
- Is followed by an exercise and rehabilitation program to strengthen the muscles and restore full joint mobility.