Which test assesses posterior knee stability by translating the tibia posteriorly?

Which test assesses posterior knee stability by translating the tibia posteriorly?

• A. McMurray's test
• B. Varus stress test
• C. Posterior drawer test
• D. Valgus stress test

Answer: (C)

Posterior tibial translation to assess posterior knee stability targets the posterior cruciate ligament. In this test, the knee is bent about 90 degrees and the examiner applies a posterior force to the tibia while stabilizing the femur. A positive result means the tibia shifts backward more than on the other knee or the end feel is soft, indicating potential PCL injury or posterior instability. This test specifically evaluates the ability of the knee to resist backward movement of the tibia, which is primarily due to the PCL and posterior joint structures. It differs from other common knee tests: McMurray's checks for meniscal tears, while varus and valgus stress tests assess the lateral and medial collateral ligaments, respectively. Understanding what each test stresses helps you pinpoint where stability is compromised.

Posterior tibial translation to assess posterior knee stability targets the posterior cruciate ligament. In this test, the knee is bent about 90 degrees and the examiner applies a posterior force to the tibia while stabilizing the femur. A positive result means the tibia shifts backward more than on the other knee or the end feel is soft, indicating potential PCL injury or posterior instability.

This test specifically evaluates the ability of the knee to resist backward movement of the tibia, which is primarily due to the PCL and posterior joint structures. It differs from other common knee tests: McMurray's checks for meniscal tears, while varus and valgus stress tests assess the lateral and medial collateral ligaments, respectively. Understanding what each test stresses helps you pinpoint where stability is compromised.