How accurate is the Lachman test?

The Lachman (anterior displacement of tibial manually at 20° of flexion) is an accurate test for detecting ACL tear (mean sensitivity 84%) (2, 8, 9). Anterior drawer test and the pivot shift tests have a sensitivity of about 62 percent.

Why is Lachman test more sensitive?

Lachman’s test is more sensitive than is the anterior drawer sign. One reason may be that it is difficult for the patient to contract his hamstrings and thus prevent forward sliding of the tibia when the knee is in only 20 degrees – 30 degrees of flexion.

What is a positive Lachman’s test?

A positive Lachman test or pivot test is strong evidence of an existing anterior cruciate ligament (ACL) tear, and a negative Lachman test is fairly good evidence against that injury.

What does Lachman’s test for?

The Lachman test is a specific clinical exam technique used to evaluate patients with a suspected anterior cruciate ligament (ACL) injury. The test relies on proper positioning and technique and is regarded as the most sensitive and specific test for diagnosing acute ACL injuries.

Which test is the most sensitive for ACL tear diagnosis?

The Lachman test is the most sensitive and the pivot shift the most specific test for the diagnosis of ACL rupture. Aust J Physiother. 2006;52(1):66.

What are the three special tests for ACL tears?

The Lachman test is the most accurate test for detecting ACL injury, followed by the anterior drawer test and the pivot shift test.

What is a positive Apley test?

The test is considered positive if it causes pain or popping. Pain or popping by internal rotation suggests the presence of a lateral meniscus injury and by external rotation the presence of a medial meniscus injury.

How is Lachman test performed?

This test is done by bending the hip 45 degrees and the knee 90 degrees, then pulling the knee forward with a sudden jerk to test the leg’s range of motion. If it moves 6 mm beyond its normal range of motion, then you may have an ACL tear or injury.

How is the sensitivity of the Lachmans test determined?

Here’s an example of a possible test to determine the sensitivity and a specificity of the Lachmans test (completely fictional). If 100 patients known to have an ACL tear were tested with the Lachman’s test, and 90 of them tested positive, then the Lachman’s test would have a 90% sensitivity.

What is the sensitivity of a diagnostic test?

Based on all the information currently available, you estimate that the patient in your office has a one in four chance of having a serious disease. You order a diagnostic test with sensitivity of 95% and specificity of 90%.

Which is the most sensitive test for Disease D?

Three tests exist that might be used in screening a population for Disease D, which you believe is present in about 1% of the population. Test A has sensitivity of 99% and specificity of 99.9%. Test B has sensitivity of 95% and specificity of 99%. Test C has sensitivity of 99.9% and specificity of 98%.

Where do you place your hand on the Lachman test?

Place the patient’s knee in about 20-30 degrees flexion. According to Bates’ Guide to Physical Examination, the leg should also be externally rotated slightly. The examiner should place one hand behind the tibia and the other on the patient’s thigh. It is important that the examiner’s thumb be on the tibial tuberosity.