Disc and Vertebral Body Morphology From Birth to Adulthood

Abstract

Objective. The aim of this study was to describe the morphology of intervertebral discs and vertebral bodies during growth in asymptomatic children and adolescents. Summary of Background Data. Earlier studies demonstrated that spinal growth occurs predominantly in vertebral bodies. This axiom introduced a vertebral-body-focus for unravelling etiological questions and achieve growth-modulation in young spinal deformity patients. Recent studies show the importance of the intervertebral discs in the early phases and possible etiology of pediatric spinal deformities. There is presently a paucity of 3D morphometric data of spinal elements during growth. Methods. A database of 298 patients aged 0 to 21 that have received a computed tomography scan for indications not related to the spine was analyzed. Custom made software was used to semi-automatically measure intervertebral disc and vertebral body morphology, corrected for orientation in all 3 planes. Results. Vertebral body height increased from birth up to adulthood, from 4-to-14 mm in the cervical, 6 to 20 mm in the thoracic, and 9 to 28 mm in the lumbar spine. This increase was 0.70 mm/year in males, more pronounced than females with 0.62 mm/year (P ¼ 0.001). Lumbar discs increased throughout growth from 4.4 to 9.0 mm, whereas thoracic discs only increased from 3.5 to 4.9 mm at age 4 and remained stable afterwards, similarly for cervical discs. The disc transverse surface area increased greatly and consistently throughout growth. Disc slenderness was stable in the lumbar spine during growth, but decreased in the thoracic and cervical spine. Overall, discs were more slender in females, especially around early adolescence. Conclusion. The spine grows predominantly in the vertebral bodies. Thoracic discs increase in height only during the first years, whereas the transverse surface area continues to increase throughout growth, thus discs slenderness decreases. Relatively, female discs remained slenderer around growth-spurt. These measurements may assist future studies on the role of disc morphology in the etiology and treatment of spinal deformity.

Spine slenderness is not an early sign of progression in adolescent idiopathic scoliosis

“…Nevertheless, mechanical instabilities due to rotational effects could be more relevant than lateral buckling, since intervertebral rotations at end vertebrae and higher torsion moments have been previously described [28,29]. Vertebral axial rotation and rotational instability have indeed been pointed out as a prominent characteristics of the scoliotic deformity in adolescents [30][31][32][33], and torsional buckling could occur more easily in a slender spine [15]. This work presents some limitations.…”

“…This overall displacement of the spinal midline can be accompanied by anterior overgrowth and lateral wedging of the vertebrae [11,12]. Recent works also showed that AIS patients can have increased spinal slenderness compared to asymptomatic controls [13][14][15]. Slenderness is "the ratio of transverse vertebral diameters to vertebral height […] combined into various slenderness ratios", according to the Scoliosis Research Society [16].…”

Spontaneous induced bone fusion in minimally invasive fusionless bipolar fixation in neuromuscular scoliosis: a computed tomography analysis

“…Thoracic and lumbar vertebral height, from T1 to L5, as well as discal height, before and at latest follow-up were calculated as the mean of maximal anterior, posterior, left and right height in sagittal and coronal plane [25]. These measurements were compared to values obtained from the literature for healthy subjects [26].…”

Convex–concave and anterior–posterior spinal length discrepancies in adolescent idiopathic scoliosis with major right thoracic curves versus matched controls

“…For the matched control, the identical levels as in the AIS patient were analyzed. The CT-scan analyses were performed using in-house developed software ( ScoliosisAnalysis 7.2, developed with MeVisLab, MeVis Medical Solutions AG, Bremen, Germany ), that was previously validated for curve morphology assessment [ 2 , 11 , 16 , 17 ]. One observer, semi-automatically segmented all the upper and lower vertebral body endplates and the spinal canal in the ‘true’ transverse plane by correcting for the coronal and sagittal angulation of each endplate (Fig.…”

“…From existing pre-operative computed tomographic (CT) databases, patients with right-sided primary thoracic AIS (Lenke 1-4) and sex-and age matched healthy controls were included [10][11][12][13][14]. These patients received these CT-scans as part of their pre-operative work-up for planning of navigation guided pedicle screw placement, which in that university medical center is part of standard care for all idiopathic scoliosis patients with an indication for posterior instrumentation.…”