When are CT angiograms indicated for patients with lower extremity fractures? A review of 275 extremities

BACKGROUND: Computed tomography Angiogram (CTA) is frequently utilized to detect vascular injuries even without exam findings indicating a vascular injury. We had the following hypotheses: 1) a CTA for lower extremity fractures with no clinical signs of a vascular injury is not indicated. 2) fracture location and pattern would correlate with the risk of a vascular injury. METHODS: A retrospective review was conducted on patients who had an acute lower extremity fracture(s) and a CTA. Their charts were reviewed for multiple factors including the presence or absence of hard or soft signs of a vascular injury, soft tissue status, and fracture location/pattern. Every CTA radiology report was reviewed and any vascular intervention or amputation due to a vascular injury was recorded. Statistical analysis was performed. RESULTS: Of the 275 CTAs of fractured extremities reviewed 80(29%) had a positive CTA finding and 16(6%) required treatment. 109(40%) of the extremities that had no hard or soft signs, all had normal CTAs. Having at least one hard or soft sign was a significant risk factor for having a positive CTA. An open fracture, isolated proximal 1/3 fibula fracture, distal and shaft tibia fractures and the presence of multiple fractures in one extremity were also associated with an increased risk for having a positive CTA. CONCLUSION: We found no evidence to support the routine use of CTAs to evaluate lower extremity fractures unless at least one hard or soft sign is present. The presence of an open fracture, distal tibia or tibial shaft fractures, multiple fractures in one extremity and/or an isolated proximal 1/3 fibula fracture increases the risk of having a finding consistent with a vascular injury on a CTA. Only 6% of the cases required treatment and all of them had diminished or absent distal pulses on presentation. LEVEL OF EVIDENCE: Level III, (diagnostic test)