Which exam finding is most consistent with an MCL injury?

Which exam finding is most consistent with an MCL injury?

• A. Tenderness over MCL
• B. Medial knee pain and increased laxity with valgus stress test
• C. Typically normal ROM if isolated
• D. May see a positive stroke test for swelling

Answer: (B)

Damage to the medial collateral ligament shows up best as tenderness along the medial knee plus a loss of resistance to a valgus stress test. When you apply valgus stress with the knee flexed around 20–30 degrees, an injured MCL cannot brace the joint, so you see increased medial opening or laxity. This combination—medial knee pain/tenderness and increased valgus laxity—is the most characteristic finding for an MCL tear, especially if the injury is isolated and the overall range of motion remains relatively preserved. The stroke test for swelling reflects effusion and isn’t specific to the MCL, and while ROM can be normal in isolated injuries, that alone isn’t as diagnostic as seeing medial laxity with valgus stress.

Damage to the medial collateral ligament shows up best as tenderness along the medial knee plus a loss of resistance to a valgus stress test. When you apply valgus stress with the knee flexed around 20–30 degrees, an injured MCL cannot brace the joint, so you see increased medial opening or laxity. This combination—medial knee pain/tenderness and increased valgus laxity—is the most characteristic finding for an MCL tear, especially if the injury is isolated and the overall range of motion remains relatively preserved. The stroke test for swelling reflects effusion and isn’t specific to the MCL, and while ROM can be normal in isolated injuries, that alone isn’t as diagnostic as seeing medial laxity with valgus stress.