Background

The 1–10% prevalence rate of adult scoliosis frequently requires expensive therapy and surgical treatments and demands further research into the disease, especially with an aging population. Most studies examining the mechanics of scoliosis have focused on in vitro testing or computer simulations. This study quantitatively defined the passive stiffness properties of the in vivo scoliotic spine in three principle anatomical motions and identified differences relative to healthy controls.

Methods

Adult scoliosis (n = 14) and control (n = 17) participants with no history of spondylolisthesis, spinal fracture, or spinal surgery participated in three different tests (torso lateral side bending, torso axial rotation, and torso flexion/extension) that isolated mobility to the in vivo lumbar spine. The spinal stiffnesses and spinal neutral zone width were calculated. These parameters were statistically compared between factor of population and within factor of direction.

Findings

Torque-rotational displacement data were fit using a double sigmoid function, resulting an in excellent overall fit (Avg. R² = 0.95). There was a significant interaction effect between populations when comparing axial twist neutral zone width vs. lateral bend neutral zone width and axial twist stiffness vs. lateral bend stiffness. The axial twist neutral zone width magnitude was significantly larger in scoliosis patients.

Interpretation

The present study is the first investigation to quantify the whole trunk neutral zone of the scoliotic lumbar spine. Future research is needed to determine if lumbar spine mechanical characteristics can help explain progression of scoliosis and complement scoliosis classification systems.

中文翻译：

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脊柱侧弯腰部躯干在基本解剖运动平面上的被动刚度特征和中性区质量。

背景

成人脊柱侧弯的患病率通常为1-10％，这需要昂贵的治疗和外科手术治疗，并且需要对该病进行进一步研究，尤其是在人口老龄化的情况下。大多数检查脊柱侧弯力学的研究都集中在体外测试或计算机模拟上。这项研究定量定义了体内脊柱侧弯脊柱在三种主要解剖运动中的被动刚度特性，并确定了相对于健康对照的差异。

方法

 没有脊柱滑脱，脊柱骨折或脊柱外科手术史的成人脊柱侧弯（n  = 14）和对照组（n = 17）参与者参加了三种不同的测试（躯干外侧弯曲，躯干轴向旋转和躯干屈曲/伸展）移动到体内腰椎。计算脊柱刚度和脊柱中性区宽度。这些参数在人口因素之间和方向因素之内进行了统计比较。

发现

扭矩-旋转位移数据使用双S型函数拟合，因此具有出色的总体拟合度（平均R ²  = 0.95）。比较轴向扭曲中性区宽度与横向弯曲中性区宽度以及轴向扭曲刚度与横向弯曲刚度时，种群之间存在显着的相互作用。脊柱侧弯患者的轴向扭曲中性区宽度幅度明显更大。

解释

本研究是第一个量化脊柱侧凸腰椎整个躯干中性区的研究。需要进行进一步的研究以确定腰椎的机械特征是否可以帮助解释脊柱侧弯的进展并补充脊柱侧弯分类系统。