Schmorl’s nodes distribution in the human spine and its possible etiology

Abstract

Although Schmorl's nodes (SNs) are a common phenomenon in the normal adult population, their prevalence is controversial and etiology still debatable. The objective was to establish the spatial distribution of SNs along the spine in order to reveal its pathophysiology. In this study, we examined 240 human skeleton spines (T4-L5) (from the Hamann-Todd Osteological Collection) for the presence and location of SNs. To determine the exact position of SNs, each vertebral body surface was divided into 13 zones and 3 areas (anterior, middle, posterior). Our results show that SNs appeared more frequently in the T7-L1 region. The total number of SNs found in our sample was 511: 193 (37.7%) were located on the superior surface and 318 (62.3%) on the inferior surface of the vertebral body. SNs were more commonly found in the middle part of the vertebral body (63.7%). No association was found between the SNs location along the spine and gender, ethnicity and age. This study suggests that the frequency distribution of SNs varies with vertebra location and surface. The results do not lend support to the traumatic or disease explanation of the phenomenon. SNs occurrences are probably associated with the vertebra development process during early life, the nucleus pulposus pressing the weakest part of the end plate in addition to the various strains on the vertebrae and the intervertebral disc along the spine during spinal movements (especially torsional movements).

The epidemiology of Schmorl’s nodes and their correlation to radiographic degeneration in 4,151 subjects

“…Furthermore, a golden standard in regard to investigative techniques and modalities has never been established. Some researchers have used consecutive MRI scans in establishing the presence of SN [10,11] in small groups of highly selected patients referred for back pain, others have investigated historical osteologic collections [3,4] and still others have investigated fresh spinal specimens from newly deceased [2,5]. In the latter cases, the spinal column has been sagittally sectioned and individual slabs have been radiographed using fine grain X-ray films.…”

“…Although 85 years have passed since Schmorl [1] first described herniations of the nucleus pulposus into the vertebral end-plates of the thoracic and lumbar spine, controversy still exists regarding the pathogenesis, etiology, epidemiology and clinical significance of these lesions [2][3][4][5][6]. It is still debated whether Schmorl's nodes (SNs) are symptomatically silent developmental or congenital aberrations of the normal vertebral anatomy or represent a common histopathological pathway for various and adverse metabolic, traumatic, infectious, degenerative or malignant factors.…”

Schmorl’s nodes

“…Dar et al [20] proposed an axial load model in which they argued that because of their erect posture and bipedal locomotion, humans must accommodate increased axial forces in addition to balancing the need for spinal mobility and stability. Given that the thoracolumbar spine bears great axial stress and is relatively mobile, it may accumulate micro-traumas that can, over time, lead to the formation of SNs in the general population [20].…”

“…Given that the thoracolumbar spine bears great axial stress and is relatively mobile, it may accumulate micro-traumas that can, over time, lead to the formation of SNs in the general population [20]. They concluded that the combination of increased range of rotational movement, anteriorly located instantaneous axis of rotation, and lowdisc thickness relative to vertebral body height in the thoracic spine makes this region more vulnerable to develop SNs.…”

The Michel Benoist and Robert Mulholland yearly European Spine Journal Review: a survey of the “surgical and research” articles in the European Spine Journal, 2010

“…And the paper by Dar et al [12] provided some further insight into an examination of some 3,000 vertebrae in skeletons. The authors conclude that these lesions, predominantly on the lower surface of the vertebra, more common in the lower thoracic and upper lumbar vertebrae, were probably associated with vertebral development in early life, and were due to the nucleus pulposus pressing the weakest part of the endplate, and related to torsional and loading of normal life, and did not represent an injury.…”