Zone of injury: a critical review of the literature.

The response of tissue to trauma is difficult to define. The zone of injury is an area surrounding a wound that, though traumatized, may not appear nonviable at initial debridement. Because of this, a policy of repeated debridements has been followed to monitor tissues for viability before final tissue coverage. Appreciation of the zone of injury has led to a controversy in the literature about how to define and approach the management of traumatic injuries requiring free-tissue coverage. This review examines the current literature with regard to the definition of the zone of injury, and seeks to establish a consensus statement about the application of free flaps to traumatized wounds. We have investigated the literature supporting the use of free flaps relying on proximally or distally based recipient vessels. Critical appraisal of this literature includes study design, determination of the power of the study, subject classification, inclusion and exclusion criteria, follow-up, and outcomes (free flap success). There has been little attempt in the literature to fully and objectively define the zone of injury. All studies to date have been observational alone. Although it would be impossible to rid a definition of the zone of injury of subjectivity entirely, a more objective, reproducible definition is vitally needed. Without a clear definition of what the zone of injury is, there can only be anecdotal, technique reports of the placement of free flap anastomoses. In this time of rising costs and lower reimbursements, this is one area that could provide vital information to improve care for patients, lessen costs, and further medical knowledge.