Is a Fracture of the Transverse Process of L5 an Indicator of the Presence and/or Severity of a Pelvic Fracture?

INTRODUCTION: A transverse process of L5 (L5TP) fracture may be associated with the presence and/or severity of a pelvic fracture. However, there is little evidence to support this view. The purpose of this study was to investigate the relationship between L5 TP fracture and the presence and/or severity of a pelvic fracture on radiograph and CT. METHODS: A total of 146 patients (82 women and 64 men; age range, 5-97 years) who were treated for pelvic fractures were evaluated. The site of pelvic fractures, presence of an L5 TP fracture with radiograph and CT, associated injuries and the need for blood transfusion, surgical intervention, and mortality were investigated retrospectively. According to the Burgess and Young classification, there were 42 unstable fractures. For each parameter, correlations between the parameters were evaluated using a chi-squared test and a logistic regression analysis. A p-value <0.05 was considered to be statistically significant. RESULTS: The sensitivity of L5 TP fractures on radiograph and CT were 51% and 95%, respectively (p < 0.0001). Multiple logistic regression analysis revealed that, of the L5 TP fractures patients on radiograph, the odds ratios for sacral fractures were 4.5 (95% confident interval [CI], 1.1-17.9); based on CT, the odds ratios for sacral fractures and the need for blood transfusion were 18.2 (95%CI, 5.1-64.9) and 3.2 (95%CI, 1.1-9.1), respectively. CONCLUSIONS: This study demonstrated that L5 TP fractures on radiograph and/or CT could indicate a high risk of sacral fracture and need for blood transfusion. When an L5TP fracture is diagnosed on initial radiograph or CT in the emergency setting, it is necessary to conduct further investigations for pelvic ring fractures and to alert the attending staff to the high-risk fracture.