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

To perform an interobserver and intraobserver agreement evaluation of the new AO Spine-DGOU classification system for osteoporotic thoracolumbar fractures (OFc). 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 (wκ) was used to determine the interobserver and intraobserver agreement. The interobserver agreement was moderate, wκ = 0.59 (95% confidence interval 0.54–0.64). The intraobserver agreement was fair, wκ = 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. This independent assessment demonstrated that new OFc allows moderate interobserver agreement and fair intraobserver agreement. Further studies are necessary prior to its widespread adoption.