A clinically useful classification of traumatic intervertebral disk lesions.

OBJECTIVE Lesions of the intervertebral disk accompanying vertebral fractures are the subject of controversy regarding the extent of surgical intervention, in part due to the lack of a comprehensive classification. The purpose of this study is to present a novel and clinically useful classification system for traumatic disk lesions after vertebral fractures. MATERIALS AND METHODS MRI of 204 disks in 102 patients with trauma-induced single-level thoracolumbar fractures referred to our trauma center between 2007 and 2011 were analyzed retrospectively. Exclusion criteria were malignant vertebral collapse, spondylodiskitis, osteoporotic fractures, and degenerative disk disease in the uninjured disks. Morphologic changes and signal alterations of the adjacent disks were determined using routine MRI of these patients and a grading system was developed. Disks were divided according to their signals into four categories from grade 0 to grade 3. Intra- and interobserver reliabilities were measured by calculating the Cohen kappa coefficient. RESULTS Of the 204 disks studied, 28.9% (59/204) were determined to be grade 0 (uninjured), 4.9% (10/204) grade 1 (disk edema), 25.5% (52/204) grade 2 (bleeding/rupture), and 40.7% (83/204) grade 3 (displacement). The kappa value for the intra- and interobserver agreement was 0.96. CONCLUSION This novel classification may improve communication between spine surgeons and radiologists as well as facilitate clinical decision making in spine surgery. Further studies need to be conducted to verify clinical relevance.