Ischaemia is a rare complication of injury to a limb but must be excluded in every case. Two distinct types occur: Type I, where a proximal arterial injury gives rise to ischaemia distally; and Type II, where a direct injury gives rise to ischaemia at the site of the injury. Whatever the nature of the insult, an ischaemic contracture only develops as a result of swelling of the soft tissues where these soft tissues are contained in un unyielding osteofascial compartment. This secondary ischaemia can only be relieved by a timely fasciotomy. The diagnosis of ischaemia in an injured limb and the indications to operate on it can usually be made on clinical grounds alone.