Background

Frequently, treatment decisions for craniocervical injuries and instability are based on imaging findings, but in vivo ligament kinematics were poorly understood. This study was to determine in vivo deformation patterns of primary ligaments in the craniocervical junction (i.e., C0–2), including the cruciform ligament, alar ligaments, and accessory ligaments, during dynamic head axial rotation.

Methods

The skulls and cervical spines of eight asymptomatic female subjects were dynamically imaged using a biplane fluoroscopic imaging system, when they performed left and right head axial rotations. Using a 3D-to-2D registration technique, the in vivo positions and orientations of cervical segments were determined. An optimization algorithm was implemented to determine ligament wrapping paths, and the resulting ligament deformations were represented by percent elongations. Using paired t-tests, ligament deformations in the end-range position were compared to those in the neutral position.

Findings

No significant differences were observed in segmental motions during left and right head rotations (p > 0.05). In general, slight deformations occurred in each component of the cruciform ligament. For the alar ligaments, the ipsilateral ligament was lengthened from −0.7 ± 13.8% to 16.6 ± 15.7% (p < 0.001*). For the accessory ligaments, the contralateral ligament was lengthened from −2.9 ± 7.5% to 10.1 ± 6.2% (p < 0.001*).

Interpretation

This study reveals that there are distinct deformation patterns in craniocervical junction ligaments during dynamic axial head rotation. These ligament deformation data can enhance our understanding of the synergic function of craniocervical junction ligaments, and guide the treatment of craniocervical instability.

中文翻译：

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双平面荧光镜追踪头部轴向旋转过程中颅颈交界处韧带变形模式

背景

通常，颅颈损伤和不稳定的治疗决定是基于影像学检查结果，但体内韧带运动学知之甚少。本研究旨在确定动态头部轴向旋转期间颅颈交界处主要韧带（即C0-2）的体内变形模式，包括十字韧带、翼韧带和副韧带。

方法

当他们进行左右头部轴向旋转时，使用双平面透视成像系统对八名无症状女性受试者的头骨和颈椎进行动态成像。使用 3D 到 2D 配准技术，确定宫颈节段的体内位置和方向。实施了一种优化算法来确定韧带缠绕路径，由此产生的韧带变形由伸长百分比表示。使用配对t检验，将末端位置的韧带变形与中性位置的韧带变形进行比较。

发现

左右头部旋转期间的节段性运动没有显着差异（p  > 0.05）。一般来说，十字韧带的每个部分都会发生轻微的变形。对于鼻翼韧带，同侧韧带从 -0.7 ± 13.8% 延长至 16.6 ± 15.7% ( p  < 0.001*)。对于副韧带，对侧韧带从 -2.9 ± 7.5% 延长至 10.1 ± 6.2% ( p  < 0.001*)。

解释

这项研究表明，在动态轴向头部旋转过程中，颅颈连接韧带存在明显的变形模式。这些韧带变形数据可以加深我们对颅颈交界韧带协同作用的认识，指导颅颈不稳的治疗。