The distribution of Schmorl's nodes in patients with low back pain or radiculopathy and their correlation with degeneration of lumbar intervertebral discs

Abstract

Objective To evaluate the distribution of Schmorl's nodes (SN) in patients with low back pain or radiculopathy,and to analyze the correlation between SN and degeneration of lumbar intervertebral discs.Methods In 2012,1024 patients with low back pain or sciatica were examined by magnetic resonance (MR) scan and plain film.There were 448 males and 576 females,with an average age of (54.3 ± 12.7) years (range,22-90).The features distribution of SN in lumbar endplate on age,sex,segment and the type and grade of intervertebral disc degeneration were analyzed retrospectively.Results Among 5120 lumbar intervertebral segments of the 1024 patients,295 (28.8％) cases and 532 (5.2％) endplates were involved with SN,302 located in the cranial and 230 in the caudal endplate.According to percent prevalence per lumbar segment,L1,2 was the most common level (29.1％),followed by L3,4 (23.7％) and L2,3 (21.1％).The incidence of SN was positively correlated with elder age,but not with sex,body weight,height,or body mass index.SN occurred more often in bulging,extrusion,Modic changes,spondylolisthesis and osteophyte comparing with normal disc or protrusion or high intensity zone.The distributions of the grade of intervertebral disc degeneration were significantly different between groups with and without adjacent SN.Intervertebral discs with adjacent SN were more degenerated than those without adjacent SN.The number,size and volume of SN were associated with the degrade of intervertebral discs degeneration.SN was divided into two types,i.e.,acute edematous SN and non-acuteSN,according to the signal type on T1-and T2-weighted MR images,and the degeneration of the corresponding intervertebral discs was more severe in the latter than the former group.Conclusion SN occurred more often in the upper lumbar spine and cranial endplate in patients with low back pain or radiculopathy.SN were correlated with elder age and the degeneration of lumbar intervertebral discs.The number,size,volume and signal type on MR images of SN impacted on its correlation with lumbar intervertebral disc degeneration. Key words: Lumbar vertebrae; Intervertebral disc degeneration; Low back pain; Magnetic resonance imaging