Which of the following is NOT part of the major knee injury triad involving a lateral knee impact?

• A. Lateral collateral ligament
• B. Medial collateral ligament
• C. Medial meniscus
• D. Anterior cruciate ligament

Answer: (A)

The major knee injury triad from a lateral knee impact involves a valgus stress with twisting that compromises the ACL, the medial collateral ligament, and the medial meniscus. The lateral collateral ligament sits on the outer side of the knee and is stressed by varus forces (pushing the knee outward), not by the valgus force that comes from a blow to the outside of the knee. Therefore, it is not part of this triad. The ACL helps prevent anterior translation and rotational instability, the MCL resists valgus stress, and the medial meniscus is often damaged because it is attached near the MCL and is compressed and torn during this mechanism. So the structure not typically involved in this injury pattern is the lateral collateral ligament.