Mirza S K, Moquin R R, Anderson P A, Tencer A F, Steinmann J, Varnau D
Department of Orthopaedic Surgery, University of Washington, Seattle, USA.
Spine (Phila Pa 1976). 1997 Apr 1;22(7):727-33. doi: 10.1097/00007632-199704010-00002.
A cadaveric cervical spine specimen fixed between a fiberglass torso and a plastic skull was used as a model to determine the effect of halo structural parameters on motion at a lesion simulated at C5-C6. In a second part, nine commercially available halo devices were compared.
To define the contributions of the various components of the halo apparatus to reducing motion in an injured cervical spine and to compare the stability offered by a sample of commercially available halo devices. Controversy exists concerning the ability of the halo apparatus to stabilize the injured cervical spine.
The halo apparatus has been shown to be the most effective nonsurgical method for stabilizing the fractured spine. Nonetheless, several clinical studies have demonstrated that unacceptably large motions can occur at the injured spinal segment stabilized with a halo apparatus.
Each cadaveric cervical spine was mounted onto a fiberglass torso and a rigid plastic skull was attached to the base of the occiput. A posterior ligamentous lesion was created between C5 and C6. The halo ring was fitted to the skull and a vest to the torso. Loads were applied to the skull in flexion, extension, and lateral bending, and relative angulation between C5 and C6 was measured with electroinclinometers. In the first part, the effect of parameters such as vest tightness, vest-thorax friction, vest deformation, and connecting bar rigidity on spinal angulation were measured using one vest. In the second part, the stability offered by each of nine commercially available halo devices was compared.
Increasing chest strap tightness and decreasing vest deformation reduced angulation at the spinal lesion. Once connecting bar joints were tightened to 25% of their recommended torque, increased tightening or adding additional bars had no effect on rigidity. Although specific vests permitted significantly greater motion in specific directions, no vest allowed greater angulation consistently in all loading planes.
Increasing vest tightness, decreasing the deformability of the vest, and ensuring a good fit can reduce motion in the fractured spine. Most commercially available halo vests provide similar mechanical stability to the injured cervical spine.
使用固定在玻璃纤维躯干和塑料颅骨之间的尸体颈椎标本作为模型，以确定头环结构参数对在C5 - C6模拟损伤处运动的影响。在第二部分中，对九种市售头环装置进行了比较。
确定头环装置各组件对减少受伤颈椎运动的作用，并比较一组市售头环装置提供的稳定性。关于头环装置稳定受伤颈椎的能力存在争议。
头环装置已被证明是稳定脊柱骨折最有效的非手术方法。尽管如此，一些临床研究表明，在用头环装置稳定的受伤脊柱节段可能会出现不可接受的大幅度运动。
将每个尸体颈椎安装在玻璃纤维躯干上，并在枕骨基部连接一个刚性塑料颅骨。在C5和C6之间造成后韧带损伤。将头环固定在颅骨上，将背心固定在躯干上。对头骨施加屈曲、伸展和侧弯负荷，并用电子倾角仪测量C5和C6之间的相对角度。在第一部分中，使用一件背心测量诸如背心紧度、背心与胸部摩擦力、背心变形和连接杆刚度等参数对脊柱角度的影响。在第二部分中，比较了九种市售头环装置各自提供的稳定性。
增加胸带紧度和减少背心变形可减少脊柱损伤处的角度。一旦连接杆关节拧紧至其推荐扭矩的25%，进一步拧紧或增加额外的杆对刚度没有影响。尽管特定的背心在特定方向上允许明显更大的运动，但没有一件背心在所有加载平面上始终允许更大的角度。
增加背心紧度、降低背心的可变形性并确保良好的贴合度可减少骨折脊柱的运动。大多数市售头环背心为受伤的颈椎提供类似的机械稳定性。
