Kraan G A, Smit T H, Hoogland P V J M, Snijders C J
Department of Neuroscience, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands.
Clin Biomech (Bristol). 2010 Jan;25(1):10-5. doi: 10.1016/j.clinbiomech.2009.09.001.
In a previous study, ligaments that connect the extraforaminal lumbar spinal nerves with the fibrous capsule of the facet joints and the dorsolateral side of the intervertebral disc were described. This anatomical configuration suggests a mechanical role in transferring extraforaminal spinal nerve traction.
One embalmed human lumbar spine was dissected from the twelfth thoracic vertebra to the first sacral vertebra to isolate the twelfth thoracic to the fourth lumbar spinal nerves. The spinal nerves from L1 to L4 were pulled at different angles with respect to the axis of the spine. Forces of 1-6N were applied. The displacements of reflective markers glued to the proximal and distal ends of the adjoining ligaments were recorded with a video system.
The spinal nerve proximal of the extraforaminal ligaments stays centred in the intervertebral foramen when pulling at an angle. At levels L1-L4 strain reduction by the extraforaminal ligaments was largest when pulling at a wider angle to the spinal axis in the sagittal plane. Proximal to the extraforaminal ligaments less displacement was seen compared to the displacement distal of the extraforaminal ligaments when pulling in longitudinal direction. A graded decrease in the displacement proximal to the extraforaminal ligaments was seen from the levels L1-L4.
Extraforaminal ligaments play an important role in the prevention of damage due to spinal nerve traction. The proximal attachments secure a spinal nerve position central in the intervertebral foramen and also reduce longitudinal tension.
在之前的一项研究中，描述了连接椎间孔外腰椎脊神经与小关节纤维囊和椎间盘背外侧的韧带。这种解剖结构提示其在传递椎间孔外脊神经牵引力方面具有机械作用。
从第十二胸椎至第一骶椎解剖一具防腐处理的人类腰椎，以分离出第十二胸椎至第四腰椎脊神经。将L1至L4脊神经相对于脊柱轴线以不同角度牵拉。施加1 - 6N的力。用视频系统记录粘贴在相邻韧带近端和远端的反光标记的位移。
当以一定角度牵拉时，椎间孔外韧带近端的脊神经在椎间孔内保持居中。在L1 - L4水平，当在矢状面与脊柱轴线以较宽角度牵拉时，椎间孔外韧带导致的应变减少最大。在纵向牵拉时，与椎间孔外韧带远端的位移相比，椎间孔外韧带近端的位移较小。从L1 - L4水平可见椎间孔外韧带近端位移呈逐渐降低趋势。
椎间孔外韧带在预防脊神经牵拉损伤方面起重要作用。近端附着点确保脊神经在椎间孔内居中位置，并减少纵向张力。
