The correlation between lumbosacral transitional anatomy and pars defect

Background: Transitional anatomy and pars defects are two common incidental findings seen on imaging of the lumbosacral spine. The purpose of this study was to investigate whether there is a correlation between these two lumbar spine phenomena. Materials and Methods: A retrospective review of spinal imaging was conducted of patients presenting with thoracolumbar fractures at our Level I Trauma Center between 2017 and 2018. Computed tomography scans from 260 patients were obtained and assessed for the presence of lumbosacral transitional anatomy and pars defect. Results: From the 260 patients reviewed, 16 patients had transitional anatomy (6%) and 20 patients had lumbar non-traumatic pars defect (8%). Only one patient presented with both transitional anatomy and pars defect. Overall, there was no difference in incidence of pars defect whether transitional lumbosacral anatomy was present (5%) or not (6.25%), P = 1.00, Fisher's exact test. Conclusion: The findings suggest that patients with transitional anatomy do not have an increased association with lumbar pars defects.