Frequency and importance of transverse process fractures in the lumbar vertebrae at helical abdominal CT in patients with trauma

PURPOSE: To evaluate the frequency and importance of transverse process fractures of lumbar vertebrae identified at helical computed tomography (CT) in patients with blunt abdominal trauma. MATERIALS AND METHODS: Helical abdominal CT scans in 536 consecutive patients with a history of blunt abdominal trauma were prospectively evaluated for transverse process fractures of the lumbar spine. The number and level of fractures were categorized and correlated to the retrospective and initial interpretations of the radiographs obtained at original trauma examination. Number and type of associated abdominal injuries were recorded. RESULTS: CT scans showed transverse process fractures in 39 (7.3%) patients. Seventy-nine fractures were identified (single fractures in 12 patients, multiple fractures in 27). Fractures were right-sided in 13 patients, left-sided in 24, and bilateral in two. Transverse process fractures of the L3 vertebra were most common (n = 25). Fractures were not reported in 20 (61%) of 33 initial radiographic assessments. Even at retrospective review, only 30 (57%) of 53 fractures were correctly identified. Transverse process fractures were associated with abdominal injuries in 20 (51%) patients; this association was statistically significant (P <.001). CONCLUSION: Initial conventional radiography is relatively insensitive in the detection of transverse process fractures of the lumbar spine. There is a statistically significant association between transverse process fractures and abdominal injury.