Distribution of Schmorl's nodes in lumbar spine and their relationship with lumbar disc degeneration

Abstract

To explore the distribution of Schmorl's nodes (SN) in normal adult lumbar spine and determine the association of lumbar disc degeneration and lumbar spine motion. A total of 1 179 individuals underwent magnetic resonance imaging (MRI) scans. They had an age range of 15-85 years and were grouped by 10 years. The distribution of SNs along lumbar spine and their relationship with age and gender were examined by single factor analysis of variance chi-square test. Spine specialists performed lumbar disc degeneration evaluations through the Pfirrmann's classification system. The relationship between SNs, age group, disc location and overall grades of lumbar disc degeneration were analyzed by multiple Logistic regression. The prevalence of SNs was 28.4%. And SNs were observed more frequently in males than females (34.6% vs 20.2%) (P < 0.01). No significant inter-group difference existed in the incidence of SNs (P = 0.18). SNs were more common at L2 and L3 vertebral bodies (14.3% vs 14.4%) while least common at S1 vertebral body (1.5%). The highest incidence of SNs was found in discs with degeneration grades III (41.9%) and IV (45.3%). The occurrence of SN, aging and disc location were positively correlated with lumbar disc degeneration grade. With a high incidence in healthy individuals, SNs occur in discs at all degrees of degeneration. And the occurrence of SNs is positively associated with lumbar disc degeneration.