Clinical features

High risk injuries are fractures of the forearm and lower leg, especially those that have been internally fixed or infected. Be especially wary in an unconscious patient.

Early features of an evolving compartment syndrome are:

• increasing pain despite immobilisation
• sensory deficit in the distribution of the peripheral nerve(s) passing through that compartment
• swelling and tenderness of the muscle compartment
• pain on passive stretching of muscles within the compartment - for example, passive extension of the toes or fingers causing increased pain in the calf or the forearm

Late features are those of tissue ischaemia with additionally, pallor, pulselessness, paralysis, coolness and loss of capillary return, but the diagnosis should be made long before these features are evident.