The lachman test is the best test to diagnose an ACL tear.

With the patient lying flat and relaxed, the physician bends the knee slightly, about 20°. He then stabilizes the thigh while pulling the shin forward. Both the amount of translation (shifting) as well as the feel of the endpoint offer information about the ACL.

The test is done on both knees: usually the patient himself feels a "stop" on the good leg but nothing on the injured one.

Other tests for diagnosing ACL rupture :

• The anterior drawer test is about the same but with the knee bent 90°.
• The pivot shift test is usually performed on a patient under anaesthesia.

Docteur J.E. Perraudin; Last updated 1 Sept 2012