Reliability Evaluation of the New AO Spine-DGOU Classification for Osteoporotic Thoracolumbar Fractures

OBJECTIVES: To perform an interobserver and intra- observer agreement evaluation of the new AO Spine-DGOU classification system for osteoporotic thoracolumbar fractures (OFc). METHODS: Complete imaging studies of 97 patients (radiographs, computed tomography scans, and magnetic resonance imaging) with osteoporotic thoracolumbar fractures were selected and classified using the OFc by 6 spine surgeons (3 senior surgeons with more than 15 years of experience and 3 surgeons with less than 15 years). After a 4-week interval, the same cases were presented to the same evaluators in a random sequence for a new classification assessment. The weighted kappa coefficient (wk) was used to determine the interobserver and intraobserver agreement. RESULTS: The interobserver agreement was moderate, wtc = 0.59 (95% confidence interval 0.54-0.64). The intraobserver agreement was fair, WK = 0.35 (95% confidence interval 0.29-0.40). Interobserver agreement slightly improved for junior staff between first and second evaluation, suggesting a learning effect. Better agreement was obtained by senior staff at the interobserver and intraobserver agreement. CONCLUSIONS: This independent assessment demonstrated that new OFc allows moderate interobserver agreement and fair intraobserver agreement. Further studies are necessary prior to its widespread adoption.