Diagnostic Accuracy of Physical Examinations for ACL Injury

The three common physical examinations that are used to aid in the diagnosis of anterior cruciate ligament (ACL) injury are the anterior drawer test, Lachman’s test, and the pivot shift test. The anterior drawer test is the oldest and easiest maneuver to learn; however, various limitations contribute to a relatively low accuracy of this examination. The poor sensitivity of the anterior drawer test is improved when anesthesia is used and for patients with chronic, rather than acute, ACL injuries. Lachman’s test has the highest sensitivity of all three tests and is useful for ruling out complete ACL ruptures with a negative test result. The specificity of Lachman’s test is high, but the pivot shift test has the highest specificity of all three physical examinations. Thus a positive pivot shift test is most accurate in diagnosing an ACL insufficiency. Studies, particularly those before the year 2000, indicate that a negative pivot shift test does not provide useful information for exclusion, and improved results of the test performed with anesthesia indicate that these false-negative results are partially caused by muscle guarding.