Correlation of Intervertebral Disc Degeneration among Different Spinal Regions in the Entire Spine in a Population-Based Cohort: The Wakayama Spine Study

Abstract

Introduction A thorough literature review about the correlation of disc degeneration (DD) among the cervical, thoracic, and lumbar region revealed no studies that focused on a population-based cohort analysis of DD in the entire spine in humans using MRI. To further elucidate the role of intraindividual factors in the development of DD, we should examine DD in the entire spine. The purpose of this study, was to examine the correlation of DD in the cervical, thoracic, and lumbar region, respectively. Materials and Methods This was a cross-sectional study of a cohort from western Japan, comprising 975 (men, 324; women, 641) of 1,011 participants (age, 21-97 years). The participants were subjected to the entire spine MRI and all intervertebral discs in the cervical (C2/3-7/Th1), thoracic (Th1/2-Th12/L1), and lumbar (L1/2-L5/S) region on sagittal T2-weighted images were evaluated according to the Pfirrmann classification system (1-3= nondegeneration; 4, 5=degeneration). The Spearman rank correlation analysis was used to determine the correlation among the number of DD at each region mutually after adjustment for age. Results The Spearman rank correlation coefficient was 0.347 (95%CI: 0.5-0.59) between the cervical region and thoracic region, 0.300 (95%CI: 0.42-0.52) between the lumbar region and thoracic region, and 0.246 (95%CI: 0.34-0.44) between the cervical region and lumbar region. Conclusion Our population-based study using the whole spine MRI revealed a highly significant intraindividual correlation between DD in the cervical region and DD in the thoracic or lumbar region. Needless to say, the biomechanical environments among the three regions are fundamentally different. This distinct individual correlation for DD could be attributed to underlying genetic factor or endogenous factors, and so on. To further elucidate the role of intraindividual factors to DD, investigations on the extent of degenerative changes using the whole spine MRI could provide useful fundamental data concerning degenerative spinal change. Disclosure of Interest None declared