Acute compartment syndrome with an atypical presentation: a useful clinical lesson

Acute compartment syndrome has been reported following a number of insults to the limb causing vascular, metabolic or other mechanical disruption within the compartment. This leads to an increase in the tissue pressure within the compartment, with subsequent reduction in tissue perfusion and eventually tissue hypoxia/ necrosis within the compartment affected. It is frequently seen in young patients, with the highest incidence in men under the age of 35 years. The outcome from compartment syndrome has been shown to be worse in those patients where diagnosis is delayed. The potential sequelae of missed diagnosis include muscle necrosis, infection and progression on to contracture and possible limb amputation. The diagnosis is reliant on a high index of suspicion. The diagnostic criteria include: (1) pain out of proportion to the initial injury; (2) pain on passive stretch of the muscles within the affected compartment; (3) palpably tense compartment; and (4) weakness and parasthesia of the areas supplied by nerves crossing the compartment. Loss of pulses is considered a late sign due to arterial occlusion. In equivocal cases and where available, compartment pressures can be measured. A compartment pressure of >35 mmHg or within 30 mmHg of diastolic pressure being suggested as indicative of compartment syndrome. This report considers the diagnostic criteria for compartment syndrome. It reflects the fact that pain-based assessment criteria cannot be absolutely relied upon when the presentation is atypical.