Common normal variants of pediatric vertebral development that mimic fractures: a pictorial review from a national longitudinal bone health study

Abstract

Children with glucocorticoid-treated illnesses are at risk for osteoporotic vertebral fractures, and growing awareness of this has led to increased monitoring for these fractures. However scant literature describes developmental changes in vertebral morphology that can mimic fractures. The goal of this paper is to aid in distinguishing between normal variants and fractures. We illustrate differences using lateral spine radiographs obtained annually from children recruited to the Canada-wide STeroid-Associated Osteoporosis in the Pediatric Population (STOPP) observational study, in which 400 children with glucocorticoid-treated leukemia, rheumatic disorders, and nephrotic syndrome were enrolled near glucocorticoid initiation and followed prospectively for 6 years. Normal variants mimicking fractures exist in all regions of the spine and fall into two groups. The first group comprises variants mimicking pathological vertebral height loss, including not-yet-ossified vertebral apophyses superiorly and inferiorly, which can lead to a vertebral shape easily over-interpreted as anterior wedge fracture, physiological beaking, or spondylolisthesis associated with shortened posterior vertebral height. The second group includes variants mimicking other radiologic signs of fractures: anterior vertebral artery groove resembling an anterior buckle fracture, Cupid's bow balloon disk morphology, Schmorl nodes mimicking concave endplate fractures, and parallax artifact resembling endplate interruption or biconcavity. If an unexpected vertebral body contour is detected, careful attention to its location, detailed morphology, and (if available) serial changes over time may clarify whether it is a fracture requiring change in management or simply a normal variant. Awareness of the variants described in this paper can improve accuracy in the diagnosis of pediatric vertebral fractures.

Identifying osteoporotic vertebral endplate and cortex fractures

“…convexity of the rest of the vertebral endplates (37). The apophyseal rings ossification occurs around the age of 10-15.…”

Skeletal Fragility in Children with Chronic Disease

“…The Genant semi-quantitative method is a morphometric assessment of vertebrae used in adults and children with ≥20% loss in vertebral height ratio accepted as clinically significant [38]. There are, however, common variants of vertebrae development not due to compression fractures which need to be taken into consideration in any screening programme of the spine, summarized in a recent review by the STOPP investigators [39]. Table 1 summarizes the examples of normal variants and artefacts that may be seen on lateral thoracolumbar X-ray in childhood [39,40,41,42].…”

Are semi-automated software program designed for adults accurate for the identification of vertebral fractures in children?

“…We are not aware of any peer-reviewed studies which have comparative data on the normal age-and sex-related values of individual vertebral levels in children. However, a recent study by Jaremko et al in 404 children on glucocorticoid treatment summarises normal variants at different ages and stages of development that may mimic fracture [22].…”