Anterior cruciate ligament (ACL)

What is an ACL injury?

Your anterior cruciate ligament is inside your knee and prevents excessive straightening of the knee joint.  An ACL injury results when forces are applied to the knee joint.

What causes an ACL injury?

An ACL injury is usually a sports-related knee injury. Most ACL injuries occur when the knee either hyperextends or knee pivots and rotates excessively causing the ligament to rupture.

There are some suggestions it is biomechanical, strength and hormonally related. In truth, it is probably a factor of all three.

Signs and symptoms

• You heard a “pop” or “snap” when moving or exercising
• Swelling or bruising around the knee
• Restriction of movement, may not be able to straighten knee
• You are unable to weight-bear on your leg
• Your knee “gives way” or “buckles”.
• Pain with certain activities
• No pain at rest usually.

Treatment

Surgery to reconstruct your ACL ligament.

Your physiotherapy treatment begins 1-2 weeks after your surgery and will aim to:

• Reduce pain and inflammation.
• Normalise your joint range of motion.
• Strengthen your knee and lower limb
• Improve patellofemoral (kneecap) alignment
• Improve your proprioception, agility and balance
• Improve your technique and function eg walking, running, squatting, hopping and landing.
• Minimise your chance of re-injury.

The rehab process can take 9-12 months to return to sport.