The posterior drawer test assess the integrity of the posterior cruciate ligament (PCL) in the knee. It is a key test for assessing posterior cruciate ligmant sprains. The PCL is one of the key ligaments that helps stabilise the knee. In particular, it prevents the tibia (shinbone) from moving too far backwards relative to the femur (thighbone). Here’s how your physio or doctor might perform the test:
Patient Positioning
The patient lies on their back (supine position) with the knee in question bent at a 90-degree angle. The foot rests on the examination table and kept in position by the examiner.
Examiner’s Position
Sits or stand at the foot of the table, with your hands around the patient’s knee with your thumbs on the tibial plateau (flat upper surface of the tibia). Wrap your fingers around the back of the calf.
Performing the Anterior Drawer Test
To conduct the test, push backwards on the tibia to apply a posterior force to the joint. Make sure you stabiliser the femur with your other hand or forearm. This movement tests the ability of the PCL to prevent the tibia moving backwards relative to the femur.
Interpreting the Results
Note the amount of posterior movement (translation) of the tibia. In a healthy knee with an intact PCL, there should be minimal movement. If there is excessive movement, this suggests a possible PCL injury or insufficiency. In particular, compare the amount of movement in the injured knee with the good knee. The degree of movement may indicate the severity of the injury.
Interpreting the results of this test accurately requires experience and a good understanding of knee anatomy. Additionally, the posterior drawer test is often part of a comprehensive knee examination. Therefore, always consider results alongside the patient’s history, symptoms, and other physical examination findings.
