Diagnostic Accuracy of Lachman Test in the Evaluation of Anterior Cruciate Ligament Injuries

Abstract

Background: In most cities and towns in the developing countries there are none or very few centers with sophisticated diagnostic investigative tests. We therefore depend a lot on clinical tests for diagnosis. The Lachman test is a very important test of the integrity of the anterior cruciate ligament. In this prospective study, the accuracy of Lachman test was compared at diagnostic arthroscopy to determine its accuracy in patients with knee injuries. Lachman test was performed in the Out-Patient clinic to determine its accuracy in the diagnosis of anterior cruciate ligament (ACL) rupture in patients with knee injuries
Objective: To determine the accuracy of Lachman test in diagnosing patients with knee injuries.
Methods: Lachman test was done and was repeated at the Operating Theatre before Arthroscopic examination of the knees to correlate the findings and accuracy of the test.
Results: At the Out-Patient Clinic, we examined 56 knees in 56 patients, 55 males and a female with mean age of 32.1 years (range 12 -55years). The right knees were 33(58.9%) and the left were 23(41.1%). The knee injuries were due to trauma in 46(86.1%), sports injuries in 9(16.1%) and dancing in 1(1.8%). Out-Patient Clinic Lachman test was truly positive in 47(83.9%), truly negative in 7(12.5%) and with a false negative in 2(3.6%). The sensitivity of Lachman test was 95.9% while the specificity was 100%.
Conclusion: Lachman test has a very high sensitivity and specificity in the diagnosis of ACL rupture in knee injuries in the Out-Patient Clinics.

Key words: Lachman test, anterior cruciate ligament, knee injuries, Out-Patient Clinics, knee arthroscopy.