Which test is most appropriate to diagnose a PCL injury?

The posterior drawer test is particularly suited for diagnosing a posterior cruciate ligament (PCL) injury. This test assesses the stability of the knee joint by evaluating how far the tibia can be pushed backwards relative to the femur. In the case of a PCL injury, movement of the tibia posteriorly is often increased compared to the unaffected knee.

The posterior drawer test provides a direct indication of the integrity of the PCL, as it specifically examines its ability to prevent posterior translation of the tibia. A significant posterior sag or excessive posterior movement during this test can confirm a PCL tear.

In contrast, the other tests mentioned assess different ligaments or structures. The anterior drawer test primarily focuses on the anterior cruciate ligament (ACL), and the Lachman's test also evaluates the ACL by checking for anterior translation of the tibia relative to the femur. Meanwhile, meniscus tests are designed to examine the cartilage of the knee rather than the ligaments. Therefore, these methods would not provide the same diagnostic clarity regarding PCL injuries as the posterior drawer test does.