[Influence of trauma mechanisms on thoracic and lumbar spinal fractures].

BACKGROUND: Vertebral body fractures (VBF) can be caused by various trauma mechanisms. The AOSpine classification system differentiates three main types of fractures according to the grade of instability. How the increasing energy of various accident mechanisms changes the complexity of the individual fracture, its localization and the occurrence of further fractures has not yet been finally investigated.

OBJECTIVE: What influence do traumatic events with different kinematics have on the localization, complexity and number of VBF in the thoracic and lumbar spine?

MATERIAL AND METHODS: In this retrospective study data from patients with a freshly traumatized VBF were analyzed. The patients were divided into six trauma groups (UFG) depending on the trauma mechanism. The VBF were classified on the basis of computed tomography (CT) imaging according to the AOSpine classification system. Testing was performed bilaterally and a significance level of 5% was used. The statistical calculations were carried out using IBM SPSS Statistics.

RESULTS: A significant increase in the severity of fractures (AO classification) was found in the high energy trauma groups (UFG III and V). In addition, the incidence of thoracic (TH) VBF was significantly increased for TH7 (p = 0.011) and TH10 (p = 0.001). In comparison to the other low energy trauma groups, the risk of a TH7 fracture was 7‑times higher after a high energy trauma (odds ratio OR = 7.0; 95% confidence interval CI = 1.4; 35.2). The UFG III (falls > 3 m) showed the highest number of fractures with a median of 2.5 (SD 1.84) VBF.

CONCLUSION: An exact reproduction of the traumatic event enables a distinction between high and low energy trauma groups to be made. In previous studies traffic accidents were recorded as one group, so an influence of the increasing kinematic energy could not be assessed. The accident kinematics can be taken into account by differentiating between high and low-energy trauma groups. In high-energy accidents the TH7 and TH10 vertebrae were found to be at risk vertebrae. In addition to the force direction, the force strength also has a decisive influence on the distribution pattern of VBF.