BACKGROUND AND PURPOSE
The development of a delayed epidural hematoma as a result of decompressive craniectomy represents an urgent and potentially lethal complication in traumatic brain injury. The goal of this study was to determine the incidence of delayed epidural hematoma and whether patterns of skull fractures on the preoperative CT scan could predict risk of a delayed epidural hematoma.

MATERIALS AND METHODS
We retrospectively evaluated medical records and imaging studies for patients with acute traumatic brain injury who underwent a decompressive craniectomy during a 9-year period. We compared patterns of skull fractures contralateral to the side of the craniectomy with the occurrence of a postoperative delayed epidural hematoma.

RESULTS
In a series of 203 patients undergoing decompressive craniectomy for acute traumatic brain injury, the incidence of a delayed epidural hematoma complication was 6% (12 of 203). All 12 patients who developed a delayed epidural hematoma had a contralateral calvarial fracture on preoperative CT at the site where the delayed epidural hematoma subsequently formed. A contralateral calvarial fracture has perfect sensitivity (100%) for subsequent development of delayed epidural hematoma in our study population. Moreover, a contralateral calvarial fracture involving 2 or more bone plates had an especially high diagnostic odds ratio of 41 for delayed epidural hematoma.

CONCLUSIONS
Recognition of skull fracture patterns associated with delayed epidural hematoma following decompressive craniectomy may reduce morbidity and mortality by prompting early postoperative intervention in high-risk situations.