Yoganandan Narayan, Stemper Brian D, Pintar Frank A, Baisden Jamie L, Shender Barry S, Paskoff Glenn
Department of Neurosurgery, Medical College of Wisconsin, VA Medical Center, Milwaukee, WI 53226, USA.
Spine (Phila Pa 1976). 2008 Mar 1;33(5):490-6. doi: 10.1097/BRS.0b013e3181657f67.
In contrast to clinical studies wherein loading magnitudes are indeterminate, experiments permit controlled and quantifiable moment applications, record kinematics in multiple planes, and allow derivation of moment-angulation corridors. Axial and coronal moment-angulation corridors were determined at every level of the subaxial cervical spine, expressed as logarithmic functions, and level-specificity of range of motion and neutral zones were evaluated.
segmental primary axial and coupled coronal motions do not vary by level.
Although it is known that cervical spine responses are coupled, segment-specific corridors of axial and coronal kinematics under axial twisting moments from healthy normal spines are not reported.
Ten human cadaver columns (23-44 years, mean: 34 +/- 6.8) were fixed at the ends and targets were inserted to each vertebra to obtain kinematics in axial and coronal planes. The columns were subjected to pure axial twisting moments. Range of motion and neutral zone for primary-axial and coupled-coronal rotation components were determined at each spinal level. Data were analyzed using factorial analysis of variance. Moment-rotation angulations were expressed using logarithmic functions, and mean +/-1 standard deviation corridors were derived at each level for both components.
Moment-angulations responses were nonlinear. Each segmental curve for both components was well represented by a logarithmic function (r2 > 0.95). Factorial analysis of variance indicated that the biomechanical metrics are spinal level-specific (P < 0.05).
Axial and coronal angulations of cervical spinal columns show statistically different level-specific responses. The presentation of moment-angulation corridors for both metrics forms a dataset for the normal population. These segment-specific nonlinear corridors may help clinicians assess dysfunction or instability. These data will assist mathematical models of the spine in improved validation and lead to efficacious design of stabilizing systems.
与临床研究中负荷大小不确定不同，实验允许进行可控且可量化的力矩施加，记录多个平面的运动学，并允许推导力矩-角度走廊。在颈椎下颈椎的每个节段确定轴向和冠状面的力矩-角度走廊，以对数函数表示，并评估运动范围和中立区的节段特异性。
节段性原发性轴向和耦合冠状运动不会因节段不同而变化。
虽然已知颈椎反应是耦合的，但尚未报道健康正常脊柱在轴向扭转力矩下轴向和冠状面运动学的节段特异性走廊。
十具人类尸体脊柱标本（年龄23 - 44岁，平均：34±6.8岁）两端固定，在每个椎体插入标志物以获取轴向和冠状面的运动学数据。对脊柱标本施加纯轴向扭转力矩。在每个脊柱节段确定原发性轴向和耦合冠状旋转分量的运动范围和中立区。使用方差分析进行数据分析。力矩-旋转角度用对数函数表示，为两个分量在每个节段推导平均±1标准差走廊。
力矩-角度反应是非线性的。两个分量的每个节段曲线都能用对数函数很好地表示（r2>0.95）。方差分析表明生物力学指标具有脊柱节段特异性（P<0.05）。
颈椎柱的轴向和冠状角度显示出统计学上不同的节段特异性反应。这两个指标的力矩-角度走廊呈现为正常人群的数据集。这些节段特异性非线性走廊可能有助于临床医生评估功能障碍或不稳定性。这些数据将有助于改进脊柱数学模型的验证，并导致稳定系统的有效设计。
