Kaigle A M, Holm S H, Hansson T H
Department of Orthopaedics, University of Göteborg, Sahlgren Hospital, Sweden.
Spine (Phila Pa 1976). 1995 Feb 15;20(4):421-30. doi: 10.1097/00007632-199502001-00004.
An in vivo animal model of lumbar segmental instability, involving both passive and active stabilizing components of the spine, was developed.
The aim of this investigation was to dynamically study the alterations in segmental kinematics as a result of interventions to the passive stabilizing components and to the lumbar musculature.
Segmental instability in the lumbar spine is associated with abnormal intervertebral motion. The majority of biomechanical studies have examined the in vitro effects of transecting individual stabilizing structures (i.e., intervertebral disc, facet joints, and ligaments), and have not simultaneously considered the effects of active musculature on spinal kinematics, which exist in the in vivo environment. Also, few studies have evaluated the kinematic behavior in the neutral region, for example, the transition phase between flexion and extension.
Four experimental groups comprised 33 pigs, each of which followed different surgical injury sequences to the L3-L4 motion segment. An instrumented linkage attached to the L3-L4 motion segment was used to measure the sagittal kinematics during dynamic flexion-extension after each surgical injury and after bilateral stimulation of the lumbar paraspinal musculature.
Injuries to the disc resulted in greater overall axial translation. Graded injuries to the facet joint mainly caused changes in sagittal rotation and shear translation. When the facet injuries were compounded by removal of the transverse processes, there was significantly greater coupled motion and increased hysteresis in the neutral region for rotation. Extensive muscular stimulation after each of the injuries caused significantly greater rotation and shear translation, along with a tendency toward reduced axial translation, when compared to the unstimulated case. Although increasing the range of motion, increased muscular activity stabilized the injured motion segment by smoothing the erratic rotation pattern of motion, particularly in the neutral region.
Because of the direct attachment to the vertebrae, both passive and active strain from the musculature influence the spinal kinematics in normal or destabilized motion segments. Although increasing the range of motion, stimulation of the musculature surrounding the injured motion segment has a stabilizing effect by reducing abrupt kinematic behavior, particularly in the neutral region where the muscles are under reduced tension. A facetectomy produces a paradoxical kinematic behavior, which enhances the unstable condition of the motion segment. Surgical and rehabilitative treatments for patients with segmental instability need to consider the physiologic influences of the spinal musculature.
构建了一种腰椎节段性不稳定的体内动物模型，该模型涉及脊柱的被动和主动稳定成分。
本研究旨在动态研究对被动稳定成分和腰部肌肉组织进行干预后节段运动学的变化。
腰椎节段性不稳定与异常的椎间运动有关。大多数生物力学研究考察了切断单个稳定结构（即椎间盘、小关节和韧带）的体外效应，并未同时考虑主动肌肉组织对脊柱运动学的影响，而这种影响存在于体内环境中。此外，很少有研究评估中立区域（例如屈伸之间的过渡阶段）的运动学行为。
四个实验组共33头猪，每组猪对L3-L4运动节段采用不同的手术损伤顺序。在每次手术损伤后以及双侧刺激腰部椎旁肌肉组织后，使用连接到L3-L4运动节段的仪器化连杆来测量动态屈伸过程中的矢状面运动学。
椎间盘损伤导致更大的整体轴向平移。小关节的分级损伤主要引起矢状面旋转和剪切平移的变化。当小关节损伤与横突切除相结合时，中立区域的耦合运动显著增加，旋转滞后增加。与未刺激的情况相比，每次损伤后广泛的肌肉刺激导致显著更大的旋转和剪切平移，同时轴向平移有减少的趋势。尽管增加了运动范围，但增加的肌肉活动通过平滑不稳定的旋转运动模式，特别是在中立区域，稳定了受损的运动节段。
由于肌肉组织与椎骨直接相连，其被动和主动应变都会影响正常或不稳定运动节段的脊柱运动学。尽管增加了运动范围，但刺激受损运动节段周围的肌肉组织通过减少突然的运动学行为具有稳定作用，特别是在肌肉张力降低的中立区域。小关节切除术会产生矛盾的运动学行为，这会加剧运动节段的不稳定状态。节段性不稳定患者的手术和康复治疗需要考虑脊柱肌肉组织的生理影响。
