Compartment syndrome resulting from undetected ulnar artery injury in the absence of a forearm fracture.

A 6-year-old boy presented following a transient crush injury to his forearm. He displayed mild abrasions but no laceration or associated fractures. The injury resulted in traumatic rupture of the ulnar artery, which caused a large forearm haematoma and an acute forearm compartment syndrome. Prompt clinical diagnosis and operative intervention were required to prevent disastrous consequences.