A 30-year-old male is struck by a car while crossing the street. He is brought in by paramedics with a blood pressure of 130/70 mmHg, heart rate of 80/min, and a right knee deformity. He is awake and alert and complaining of severe right knee pain. His airway is intact and breath sounds are equal bilaterally. Abdominal and pelvic exams are unremarkable. There is swelling and an obvious deformity of his right knee. His right foot is pale and cool, with a 6 s capillary refill, whereas the left foot is pink and warm with <2 s capillary refill. Pulse examination reveals normal 2+ pulses in his left femoral, popliteal, dorsalis pedis (DP), and posterior tibial (PT) arteries. On the right, there is a 2+ femoral pulse. Doppler signals on the left foot are triphasic, whereas on the right they are monophasic. Due to severe knee pain, neither the right knee nor the popliteal pulse can be examined. The right dorsalis pedis and posterior tibial artery pulses are non-palpable. Sensory and motor function is intact bilaterally. There is no tenderness or deformity in the right thigh or in the tibia or ankle. The right lower extremity ankle–brachial index (ABI) is 0.20, whereas the left is 1.0.