Which test is best suited to assess medial collateral ligament integrity?

Which test is best suited to assess medial collateral ligament integrity?

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

Answer: (D)

The medial collateral ligament resists forces that push the knee inward (valgus stress). To assess its integrity, you apply a valgus stress to the knee, meaning you push the knee inward while stabilizing the ankle, which opens the medial side of the joint. This stress is most telling when focused at the right angle: about 25–30 degrees of knee flexion tends to isolate the MCL, while testing at 0 degrees can reveal involvement of the MCL along with the joint capsule. A positive result is increased medial joint space opening or pain compared with the opposite knee, indicating MCL injury. Other tests target different structures: the posterior drawer test checks the posterior cruciate ligament; McMurray's test looks for meniscal tears; the varus stress test checks the lateral collateral ligament. Since the valgus stress test specifically stresses the medial collateral ligament, it is the best choice to assess MCL integrity.

The medial collateral ligament resists forces that push the knee inward (valgus stress). To assess its integrity, you apply a valgus stress to the knee, meaning you push the knee inward while stabilizing the ankle, which opens the medial side of the joint. This stress is most telling when focused at the right angle: about 25–30 degrees of knee flexion tends to isolate the MCL, while testing at 0 degrees can reveal involvement of the MCL along with the joint capsule. A positive result is increased medial joint space opening or pain compared with the opposite knee, indicating MCL injury.

Other tests target different structures: the posterior drawer test checks the posterior cruciate ligament; McMurray's test looks for meniscal tears; the varus stress test checks the lateral collateral ligament. Since the valgus stress test specifically stresses the medial collateral ligament, it is the best choice to assess MCL integrity.