Anatomy clinical correlates Quiz: Ace Your Exams

A 27-year-old man presents to the emergency department with emergency medical services after a high-speed motor vehicle collision. The patient was the front-seat passenger of a vehicle that rear-ended another car while traveling at 45 miles per hour. The patient's primary survey is intact, and the secondary survey is notable for left knee swelling and ecchymoses. Vital signs are within normal limits. Physical examination of the left knee demonstrates a large joint effusion and ecchymoses. A “soft” end-feel and increased posterior translation of the left tibia is noted when the examiner applies a posterior force anteriorly to the upper tibia. Which of the following best describes the mechanism of injury resulting in this patient's clinical condition?