Orthopaedic Bioengineering Research Center, Department of Orthopaedic Surgery, Newton-Wellesley Hospital, Newton, MA, USA; Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Orthopaedic Bioengineering Research Center, Department of Orthopaedic Surgery, Newton-Wellesley Hospital, Newton, MA, USA; Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Department of Orthopaedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
Clin Biomech (Bristol). 2021 Aug;88:105442. doi: 10.1016/j.clinbiomech.2021.105442. Epub 2021 Jul 29.
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.
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.
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*).
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.
颅颈交界区（C0-2）损伤和不稳定的治疗决策通常基于影像学发现，但对其内部韧带的运动学知之甚少。本研究旨在确定颅颈交界区（C0-2）主要韧带（即十字韧带、翼韧带和副韧带）在动态头轴向旋转时的体内变形模式。
使用双平面荧光透视成像系统对 8 名无症状女性受试者的颅骨和颈椎进行动态成像，当她们进行左右头轴向旋转时。使用 3D 到 2D 配准技术，确定颈椎节段的体内位置和方向。实施优化算法以确定韧带包裹路径，并用伸长率表示韧带的变形。使用配对 t 检验比较末端位置和中立位置的韧带变形。
在左右头旋转时，节段运动没有明显差异（p>0.05）。通常，在十字韧带的各个组成部分中会发生轻微的变形。对于翼韧带，同侧韧带从-0.7±13.8%伸长至 16.6±15.7%（p<0.001*）。对于副韧带，对侧韧带从-2.9±7.5%伸长至 10.1±6.2%（p<0.001*）。
本研究揭示了在动态头轴向旋转过程中颅颈交界区韧带存在明显的变形模式。这些韧带变形数据可以增强我们对颅颈交界区韧带协同功能的理解，并指导颅颈不稳定的治疗。
