Open Zone V Injuries

Clinical presentation

Open zone V injuries overlie the MCPJ. Open injuries in this area must be suspected to be a human bite until proven otherwise [3]. Indeed such injuries are called ‘fight bites’, and in addition to tendon injury, joint involvement and septic arthritis are likely.

Due to the broad sagittal band and extensor tendon interconnections, the ruptured tendon does not retract and extensor lag is usually mild. The position of the joint at the time of injury must be remembered as the tendon laceration may be proximal to the skin wound.

Clinical management

ED management of open zone V injuries may include a wound exploration to establish the depth of the wound and any tendon or joint involvement. Alternatively, these injuries may be referred urgently to a hand surgery unit.

It is recommended that all zone V wounds require surgical exploration and any joint involvement needs thorough debridement and washout.

Admission for hand elevation and IV antibiotics is also required. Zone V tendon injuries from a human bite should undergo delayed repair when the risk of infection and septic arthritis are minimised [2].