Final answer:
The male adult experiencing severe pain, a swollen and bruised leg, and a leg shorter than the other is most likely at risk for compartment syndrome following a motor vehicle collision. This condition requires immediate medical attention to prevent serious complications.
Step-by-step explanation:
Based on the symptoms provided in the question, the injured man is at greatest risk for developing a compartment syndrome. This serious condition occurs when increased pressure within one of the body's compartments (groups of muscles, nerves, and blood vessels) results in insufficient blood supply to the area. Symptoms, like those described including severe pain, edema (swelling), and bruising (ecchymosis), and a leg that appears shorter (possibly due to displacement of bone and muscle) are indicative of the syndrome. The shortened limb could result from a fracture of the femur or other nearby bone, causing muscle contraction and leg shortening.
After a motor vehicle collision, immediate medical assessment and intervention are critical to prevent further damage and complications. Treatment often involves a surgical procedure known as a fasciotomy to relieve the pressure. Failure to treat compartment syndrome promptly can lead to tissue necrosis, permanent muscle damage, or limb amputation.