Iliac crest orientation and geometry in able-bodied and non-treated adolescent idiopathic scoliosis girls with moderate and severe spinal deformity

Abstract

Purpose To identify pelvic rotation and/or distortion in able-bodied and untreated AIS girls with moderate and severe scoliosis and verify association of pelvic morphological changes with Cobb angle increase. Methods The 3D coordinates of nine anatomic bony landmarks were identified to estimate pelvic orientation using a Flock of Birds system. The distances between the first sacral vertebral body (S1) and each of the eight iliac spine landmarks in all three planes were calculated to identify pelvic distortion. Analysis of variance was used to assess pelvic orientation and determine pelvic distortion. Pearson coefficients of correlation were used to identify any relationships between Cobb angle and pelvic morphological parameters.Results Pelvic orientation was similar in able-bodied and scoliotic girls regardless of the severity of the spinal deformity. Significant differences were observed in pelvic morphology between AIS with severe untreated scoliosis and those with a moderate scoliosis for the right anterosuperior iliac spines (ASIS), the tip of the superior iliac crest (TSIC) and the widest tip of the iliac crest (WTIC) widths from S1. Statistically significant correlations were observed between the Cobb angles and the iliac crest distances measured from S1. Conclusions Differences in iliac spine geometries occurred in the transverse plane correlating to Cobb angles which suggest altered bone growth in AIS girls. Such findings could indicate right thoracic spinal deformity as a result of pelvic torsion.

Three-dimensional vertebral wedging and pelvic asymmetries in the early stages of adolescent idiopathic scoliosis

“…They assume that a pelvic rotation-inducing system transfers this torsion to the spine without providing further explanations. Based on a correlation between Cobb angle progression and iliac spine asymmetries, Stylianides et al [24] proposed that an asymmetrical bone growth in the iliac crest could generate horizontal torsion of the pelvis described by Burwell et al [23]. Our 3D radiographic study supports this assumption because asymmetries were noted in different locations on the coxal bones.…”

“…Mahaudens et al [50] reported thicker iliac crests in AIS than in nonscoliotic individuals. Asymmetries were also reported between the right and left AIS iliac crest widths and depths compared with nonscoliotic girls [24]. Our results are the first to document radiographic pelvic 3D asymmetries at the very onset of the scoliosis and the persistence of these with as scoliosis progresses.…”

“…Pelvic abnormalities were reported by Duval-Beaupere et al [7], and several authors proposed that these are consequential to abnormal bone growth [23,24]. This supports the concept that the pelvis behaves as a vertebra [25]; however, its link with spinal deformity remains unclear.…”

“…Both frontal and sagittal plane projections of the 3D shape of the pelvis and its spatial orientation could be misleading [27,28]. Stylianides et al [24] are among the first to report 3D iliac crest asymmetries in able-bodied girls and in untreated AIS with moderate and severe scoliosis from cutaneous measurements using a 3D electromagnetic pointer. To our knowledge, no one has described the 3D morphology of the pelvis from bony landmarks on the ilium and pubis in AIS.…”

Effects of frontal and sagittal thorax attitudes in gait on trunk and pelvis three-dimensional kinematics

“…The overall mean of this motion was −0.12 ± 2.48°(mean ±SD) with values ranging from −4.30°to 5.72° (Table 1). Subjects were arbitrarily divided according to the median as the division point, as in previous studies [1,26,27]. Those with the lower values (0.86 ± 0.71°) were assigned to the small range of trunk bending; the remaining subjects were assigned to the large range (3.12 ± 1.01°).…”