Evaluation of Disc and Endplate Degeneration in AO Type A Fractures Using Magnetic Resonance Imaging Analysis.

ABSTRACT

OBJECTIVE: Disc degeneration after trauma has been the focus of several investigations, although vertebral endplate changes have received comparatively less attention. The main aim of the present study is to radiologically evaluate the prevalence of the degree of degeneration of the adjacent discs and endplates after AO type A thoracolumbar fractures. METHODS: We retrospectively reviewed 25 patients with an AO type A injury (50 discs and 150 endplates). The type of disc lesion adjacent to the fractured vertebra was classified using the Pfirrmann and Oner classifications immediately after trauma and at the 1-year follow-up. The endplate defects were assessed using the endplate scoring system (total endplate score 1-6) in T1-weighted images. The kyphosis angle and vertebral body height were also measured. RESULTS: The study population consisted of 18 men (72%) and 7 women (28%), with a mean age of 38.9 ± 11.3 years. Overall, 28% of the fractures were type A1, 4% were type A2, 24% were type A3, and 44% were type A4. On statistical analysis, a significant change was found in the degree of degeneration in the cranial adjacent disc using both the Oner (P = 0.004) and Pfirrmann (P = 0.001) classifications at the end of 1 year. The morphological changes at the cranial adjacent discs at 1 year of follow-up showed a strong positive correlation with superior endplate degeneration. CONCLUSIONS: The results from the present study indicate that endplate fractures of vertebrae in patients with thoracolumbar burst fractures can cause disc degeneration, especially at the cranial endplate.