Which test is used to assess the LCL by applying a varus stress to the knee?

Which test is used to assess the LCL by applying a varus stress to the knee?

• A. Varus stress test
• B. Thessaly test
• C. Valgus stress test
• D. McMurray test

Answer: (A)

Testing lateral knee stability hinges on how the LCL resists varus stress. The LCL runs along the outside of the knee and acts to prevent the lower leg from bowing inward when the knee is stressed laterally. By applying a varus force to the knee, you tighten and load the LCL and the lateral joint structures. If the LCL is injured or lax, you’ll see increased gapping at the lateral joint line or reproduce pain compared to the other knee, indicating a positive test. For the test, the knee is typically flexed about 20–30 degrees to isolate the LCL (at 0 degrees, the capsule and other structures also contribute to stability). A varus stress is then applied at the ankle to push the distal leg medially, causing a varus deformity moment at the knee. A normal knee shows little to no laxity, whereas a damaged LCL shows excessive lateral opening or tenderness. Other tests assess different structures: the valgus stress test targets the medial collateral ligament, the Thessaly test checks for meniscal tears, and the McMurray test also evaluates meniscal pathology.

Testing lateral knee stability hinges on how the LCL resists varus stress. The LCL runs along the outside of the knee and acts to prevent the lower leg from bowing inward when the knee is stressed laterally. By applying a varus force to the knee, you tighten and load the LCL and the lateral joint structures. If the LCL is injured or lax, you’ll see increased gapping at the lateral joint line or reproduce pain compared to the other knee, indicating a positive test.

For the test, the knee is typically flexed about 20–30 degrees to isolate the LCL (at 0 degrees, the capsule and other structures also contribute to stability). A varus stress is then applied at the ankle to push the distal leg medially, causing a varus deformity moment at the knee. A normal knee shows little to no laxity, whereas a damaged LCL shows excessive lateral opening or tenderness.

Other tests assess different structures: the valgus stress test targets the medial collateral ligament, the Thessaly test checks for meniscal tears, and the McMurray test also evaluates meniscal pathology.