The Lachman Test is among the well known and widely used techniques of making and adjudication upon the hyperextension of the anterior cruciate ligament in the knee. Along with anterior drawer test, it can be referred to as one of the most widely used orthopedic tests used by orthopedics in clinics for the purpose of evaluation.
John Lachman is credited with describing the methods adopted in the Lachman Test and the probable conclusions that may be drawn from the results of those methods. He popularized the use of this test for the purposes of assessing acute knee injuries. Hence the test has been named ‘Lachman Test’ in memory of John Lachman who was a renowned orthopedic.
The Lachman Test has two uses. As stated in the above paragraph it can be used to assess the extent of injury or amount of hyperextension of the anterior cruciate ligament. The second most crucial usage of the Lachman Test is in clinical setting. This method of assessment of the injuries to anterior cruciate ligament is considered more foolproof and conclusive than the traditional anterior drawer test.
Method and process of the Lachman Test
The Lachman Test is one of the most effective clinical tools used by orthopedic surgeons and physicians in making proper assessment of the extent of injury to anterior cruciate ligament in a patient’s knee.
The person on whom the Lachman Test is about to be conducted is asked to lay on a platform with his face facing towards the ceiling. The patient should lie down with his back and torso perfectly straight. Thereafter the doctor, his assistant or anyone conducting the Lachman Test bends the injured knee to about 20-30 degrees in the first step of the Lachman Test.
Doctor has to hold the area surrounding the patient’s injured knee in such a manner using both his hands in such a manner that one of his hands is holding the tibia. The other hand of the examiner or the doctor must be carefully but firmly placed upon the patient’s thigh. It is of paramount significance for proper conduct of the Lachman Test that the doctor’s thumb is placed exactly above the tibial tuberosity. After this stage of the Lachman Test is completed the assessment part of the test is initiated.
In terms of the outcome of the test, this is extremely crucial and important. The doctor is required to stretch the tibia of the injured knee using the hands that were strategically placed during the initial stage of the Lachman Test. The amount of movement that the tibia of the injured knee shows is crucial to any proper determination being made by the doctor.
The amount of movement of the tibia is evaluated against the amount of movement of the femur and the doctor concludes the results of the test by making comparative evaluation. In case the anterior cruciate ligament of the injured knee is intact and functional the forward movement of the tibia is restricted to a fair amount a