Understanding the Posterior Drawer Test of the Knee Assessment
To assess the integrity of the **Posterior Cruciate Ligament (PCL)**.
Watch How It's Done
How do I start?
Patient is supine. Hip is flexed to 45°, and the knee is flexed to **90°**. Foot is stabilized by the examiner sitting on it.
What happens?
The examiner grasps the tibia just below the joint line and applies a **straight posteriorly directed force** (pushing backward).
In Plain English
What Does a Positive Result Mean?
**Excessive posterior translation** of the tibia on the femur, compared to the unaffected side, or a 'soft' (absent) endpoint, indicating a PCL tear.
Helpful Tip:
Often confused with the 'sag sign' (gravity-induced displacement). Always check the starting position for posterior sag first.
Safety First
This guide is to help you understand what happens in a clinic. Do not try to diagnose yourself. If you have severe pain, swelling, or cannot put weight on your leg, please visit an urgent care center or your doctor immediately.
Other Knee Tests
Pivot Shift Test
To dynamically assess for **anterolateral rotatory instability** of the knee, which is highly indicative of a **complete ACL tear**.
Posterior Sag Sign (Gravity Drawer Test)
To detect a rupture of the **Posterior Cruciate Ligament (PCL)** by observing the effect of gravity.
Slocum Test (Anterolateral Rotatory Instability)
To assess for **anterolateral rotatory instability** and the function of the **Anterolateral Ligament** (a dynamic variant of the Anterior Drawer).
Thessaly Test
To assess for **meniscal tears** by dynamically loading the meniscus in a weight-bearing, rotational manner.