Which tests are commonly used to assess ACL integrity?

• A. Tinel sign and Phalen test
• B. Anterior drawer test and Lachman test
• C. Varus stress test and Valgus stress test
• D. McMurray test and Patellar grind test

Answer: (B)

Assessing ACL integrity centers on how much the tibia can move forward relative to the femur, especially when the joint is loaded in a way that stresses the ACL. The two most common tests for this are the Lachman and the anterior drawer.

The Lachman test is performed with the knee flexed about 20–30 degrees. Stabilizing the femur with one hand while pulling the tibia forward with the other minimizes hamstring guarding and directly stresses the ACL. In an ACL rupture, you’ll see increased anterior translation of the tibia and often a soft or absent end feel. This test is prized for its high sensitivity and specificity.

The anterior drawer test is done with the knee flexed to 90 degrees and the tibia pulled forward. It also looks for increased anterior tibial movement, signaling ACL insufficiency. It can be influenced by patient relaxation and hamstring tension, so it’s somewhat less reliable on its own but remains a standard part of the examination.

The other tests listed target other knee structures: Tinel sign and Phalen test assess carpal tunnel issues in the wrist; varus and valgus stress tests examine collateral ligaments; McMurray and patellar grind tests relate to meniscal and patellofemoral problems, respectively.