Anterior cruciate ligament injury#Lachman test

The Lachman test is, together with the anterior drawer test known as an investigation method that is used in traumatology and orthopedics for the detection of a cruciate ligament injury of the knee joint.

Implementation

When Lachman test both knees are always examined in order to compare the calculated values ​​with each other. To this end, the patient lying usually the tested knee is held in 20 to 30 ° flexed position. Ideally, the heel of the leg rests on a couch. The examiner grasps the lower leg with both hands so that his index fingers in the popliteal fossa. The lower leg will be pulled forward. The degree of displacement of the tibia relative to the femur (drawer) provides information as to whether a violation of the cruciate ligament is present or not.

Result

For the assessment of the Lachman test first, the quality of the stopper ( firm or soft ) is used and on the other compared the drawer of the healthy knee with the drawer of the injured knee. By use of the difference, which is listed in millimeters, can be a statement about the stability of the knee hit. To this end, we distinguish four different levels of stability:

To secure the diagnostic magnetic resonance imaging ( " MRI ") or an arthroscopy can then be performed, for example. For the latter, there is also the possibility of therapy in the form of a Kreuzbandteilresektion ( at crack initiation ), a reattachment of the torn- tape to its natural point of attachment or a cruciate ligament reconstruction.

Sources of error and certainty of the diagnosis

The main source of error lies in the masking of a posterior cruciate ligament tear. In this case, falling of the leg on the thigh to the rear. A to-front -drag then suggests a rupture of the anterior cruciate ligament, which actually is but intact. Therefore, care should be taken that the knee joint prior to testing in a " neutral position " is. In general, the Lachman test as the most reliable non-invasive and pain-free / low clinical examination methods for the assessment of the state of the anterior cruciate ligament. When the anterior cruciate ligament, the sensitivity is approximately 90 %, which the test has a much higher significance than the drawer test.

Namesake and first description

The Lachman test is named for the U.S. orthopedic surgeon John Lachman from Temple University (Philadelphia ). The Lachman test was first described in 1976 by his successor at Temple University, Joseph S. Torg. Torg reported in this publication that Lachman had this simple and reliable test taught and practiced for many years at Temple University.

1992 found Paessler and Michel that the Greek physician George Noulis this - described method in 1875 in his dissertation - today Lachman test called.