Novel Modic grading scoring system and its clinical validation: a preliminary investigation

Purpose To propose a novel Modic grading scoring system and explore the relationship between the Modic grading score and disc degeneration, disc herniation, disc height, and clinical symptom scores. Method In total, 194 patients were included in the study. The new Modic grading scoring system included four indicators: invaded vertebral height, invaded endplate length, endplate morphology, and grade of endplate defects. The severity of Modic changes was visually quantified by numerical scores, and the kappa value was used to verify the interobserver and intraobserver reliability. Spearman correlation analysis was used to explore the relationship between the Modic grading score and intervertebral disc degeneration, disc herniation, disc height, and clinical symptom scores. Results The interobserver and intraobserver reliability showed substantial to almost perfect agreement in the new Modic grading scoring system. The Modic grading score was positively correlated with intervertebral disc degeneration ( r = 0.757, p < 0.001) and negatively correlated with the intervertebral disc height index ( r = − 0.231, p < 0.001). There was no significant correlation between the Modic grading scoring system and disc herniation ( r = 0.369, p = 0.249). Additionally, there was no significant correlation between the Modic grading score and the Japanese Orthopaedic Association score ( r = − 0.349, p = 0.25), Oswestry Disability Index score ( r = 0.246, p = 0.11), or visual analogue scale score ( r = 0.315, p = 0.35). Conclusion The new Modic grading scoring system had good interobserver and intraobserver reliability. The Modic grading score was positively correlated with intervertebral disc degeneration and negatively correlated with the intervertebral disc height.