Introduction: Thoracolumbar spine injury is frequently seen with high-energy trauma but dislocation fractures are relatively rare in spinal trauma, which is often neurologically severe and requires urgent treatment. Therefore, it is essential to understand other concomitant injuries when treating dislocation fractures. The purpose of this study is to determine the differences in clinical features between thoracolumbar spine injury without dislocation and thoracolumbar dislocation fracture.
Methods: We conducted an observational study using the Japan Trauma Data Bank (2004–2019). A total of 734 dislocation fractures (Type C) and 32,382 thoracolumbar spine injuries without dislocation (Non-type C) were included in the study. The patient background, injury mechanism, and major complications in both groups were compared. In addition, multivariate analysis of predictors of the diagnosis of dislocation fracture using logistic regression analysis were performed.
Results: The incidence of thoracolumbar spine injury was 9.2%, and among thoracolumbar spine injuries, the incidence of dislocation fractures (type C) was 2.2%. The median age of Non-type C increased from 43 to 62 years during the study period, and there was a significant increase in age in the later stages of the study (P < 0.001). The median age of Type C increased from 35 to 44 years during the study period (P < 0.05). Items significantly more frequent in Type C than in Non-type C were males, hypotension, bradycardia, percentage of complete paralysis, falling objects, pincer pressure, accidents during sports, and thoracic artery injury (P < 0.001); items significantly more frequent in Non-type C than in Type C were falls and traffic accidents, head injury, and pelvic trauma (P < 0.001). Logistic regression analysis showed that younger age, male, complete paralysis, bradycardia, and hypotension were associated with dislocation fracture.
Discussion: We found out that the incidence of dislocation fractures was rare. Over a period of 15 years, the age of people receiving thoracolumbar injuries increased. The older age at injury, which reflects the increasing average age of the Japanese population, is thought to be a contributing factor. In addition, more injuries that were previously fatal are now being brought to the emergency room than in previous decades. It is possible that the same changes can be seen in overall thoracolumbar spine injuries. Five associated factors were identified in the development of thoracolumbar dislocation fractures. Hypotension on arrival, bradycardia on arrival, and complete paralysis are common symptoms that may occur during neurogenic shock. This study suggests that dislocation fractures may lead to complete paralysis or to neurogenic shock.