Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Department of Orthopedic Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.
Spine Deform. 2021 Jul;9(4):923-932. doi: 10.1007/s43390-020-00279-y. Epub 2021 Jan 15.
The sagittal curvature of the spine is hypothesized to play an important role in induction of spinal deformities in adolescent idiopathic scoliosis. We previously showed an S shaped flexible rod, with the same curvature as the pediatric sagittal spinal curve, produces scoliotic-like deformities under physiologic loading. Yet, detailed characteristics of the pediatric sagittal spinal curves associated with higher risk of scoliosis are not well defined.
A total of 32 patients in a population with a high prevalence of idiopathic-like scoliosis, 22q11.2 deletion syndrome (22q), were included and followed up for at least two-years. We developed a reduced order finite element model (FEM) of the sagittal profile of these 32 patients where the spine was modeled as an S shaped elastic rod. We related the geometrical parameters of the sagittal curves and the deformed FEM of the corresponding S shaped rods to the risk of scoliosis development at two-year follow-up in this cohort.
Variations in the sagittal curvature in the cohort of 22q patients resulted in five different deformity patterns shown by finite element analyses. Two sagittal plane deformity pattern groups had high rate of scoliosis development (86% and 100%) whereas the other 3 groups had less than 50% rate of scoliosis development (40%, 33%, and 0%). The pre-scoliotic position of the inflection point (where lordosis turns into kyphosis), the ratio of the spinal curvatures above and below the inflection point, and the length of the spinal curve above and below the inflection point were significantly different between the five deformity patterns groups, p < 0.05.
Combination of geometrical parameters of the sagittal profile prior to onset of scoliosis can relate to the development of spinal deformity in pediatric population.
脊柱矢状曲度被认为在青少年特发性脊柱侧凸中诱导脊柱畸形中发挥重要作用。我们之前的研究表明，与儿科矢状脊柱曲线曲率相同的 S 形柔性杆在生理负荷下会产生类似脊柱侧凸的畸形。然而，与更高的脊柱侧凸风险相关的儿科矢状脊柱曲线的详细特征尚未明确定义。
共纳入 32 例 22q11.2 缺失综合征（22q）患者，这些患者来自脊柱侧凸发病率较高的人群，并至少随访两年。我们为这 32 名患者开发了矢状曲线的降阶有限元模型（FEM），脊柱被建模为 S 形弹性杆。我们将矢状曲线的几何参数与相应 S 形杆的变形 FEM 相关联，以了解该队列中两年随访时脊柱侧凸发展的风险。
22q 患者组的矢状曲率变化导致有限元分析显示出五种不同的畸形模式。两个矢状面畸形模式组的脊柱侧凸发展率较高（86%和 100%），而其他 3 个组的脊柱侧凸发展率低于 50%（40%、33%和 0%）。拐点（脊柱前凸变为后凸的位置）的前脊柱侧凸位置、拐点上下脊柱曲率的比值以及拐点上下脊柱曲线的长度在 5 种畸形模式组之间存在显著差异，p 值均<0.05。
在脊柱侧凸发生之前，矢状曲线的几何参数组合可以与儿科人群脊柱畸形的发展相关。
