Which of the following injuries is likely to cause a severe vascular damage?

knee can be dislocated only by considerable violence, as in a road accident. The cruciate ligaments and one or both lateral ligaments are torn. Clinical features Rupture of the joint capsule produces a leak of the haemahrosis, leading to severe bruising and swelling. This may be the only clue on inspection, especially if the dislocated joint has reduced spontaneously. Otherwise, the diagnosis is straightforward as there is gross deformity . The circulation in the foot must be examined because the popliteal aery may be torn or obstructed. Repeated examination is necessary as compament syndrome is also a risk. Common peroneal nerve injury occurs in nearly 20 per cent of cases; distal sensation and movement should be tested. REF:Apley's system of ohopaedics - 9th edn - pg no 884.