Anterior Cruciate Ligament Tear

Question 1

How does an ACL tear occur?

Answer 1

Most common in team sports.
Mechanism is often a sideways blow to the lateral knee whilst in a slight flexion.
Can also occur through overextension of the knee with force from landing a jump.

Question 2

Any complications of an ACL tear?

Answer 2

Often occurs in combination with damage to the articulations cartilage, medial collateral ligament, or a tear to the meniscus.

Question 3

How would you know it’s an ACL tear?

Answer 3

Audible pop/crack
Very painful
Usually unable to continue playing or if they do knee feels unstable
Restricted range of motion
Widespread tenderness in knee 
X-ray

Question 4

How would you treat an ACL tear?

Answer 4

If only a partial tear surgery may not be required, just rest until paid disappears and then muscle strengthening and proprioception exercises, takes long time due to lack of blood flow.
If complete tear, requires surgery. Commonly an autograft where middle third of patella tendon used to replace damaged ligament, but can also use allograft where cadaver ligament/tendon is used.
Then rom training, muscle strengthening and proprioceptive exercises.

Question 5

Any predisposing factors of ACL tear?

Answer 5

Muscle imbalance between quad and hamstring can increase incidence