不同角度牵引治疗颈椎病的生物力学研究

Biomechanical analysis of traction from different angles in the treatment of cervical spondylosis

目的通过建立生理曲度变直的颈椎全节段有限元模型,使用不同角度模拟加载牵引,进行生物力学的对比与分析,为临床提供合理牵引方式的依据。方法选取颈椎曲度变直患者采集CT数据,采用专用生物力学有限元软件构建包含韧带、肌肉组织的完整颈椎全节段模型,进行验证后,再在相同的边界和加载条件下,采用中立、前屈和后伸位各角度进行模拟牵引,分析椎间孔、关节突关节、钩锥关节、椎间隙的距离变化以及椎间盘髓核、基质的应力变化。结果当牵引角度为前屈0°-15°时,椎间孔、椎间隙、后关节突之间的间距加大,椎间盘的拉应力适宜,压应力较小;后伸位牵引,随着角度的增大,相邻椎间孔间距变小,其中C5-6、C6-7最明显;椎间盘前端间距变大,后端间距变小,髓核前移之势明显;角度小于10°时,各个椎间盘基质和髓核的最大压应力都很小,不出现应力集中。钩锥关节间距在0°牵引时最大,随前屈、后伸角度变大间距变小。结论建议临床对于神经根型颈椎病患者应采用不超过15°的前屈位牵引,钩锥关节增生明显者,宜采用0°的牵引,单纯椎间盘膨出的早期患者可以采用小于10°的后伸位牵引,利于椎间盘的回纳、缓解肌肉紧张和恢复异常曲度。

Objective To establish an accurate finite element model of cervical spine with straight curvature,use different angles simulating traction load,and analyze the biomechanics data,to obtain basis of clinical reasonable traction.Methods A high quality finite element model of complete cervical spine including ligament and muscle is generated with CT scan data from patients with straight curvature cervical spine and specialized biomechanical finite element software. After verification,the simulation traction of cervical spine is loaded on neutral,flexion and extension under the same boundary and loading conditions. The results will be used to analyze the distance changes of foramen,facet joints,hook cone joints and intervertebral,stress changes of nucleus pulposus and matrix. Results When the flexion angle is 0- 15 degree,the distance between intervertebral foramen,luschka joint and posterior processus articularis is enlarged,the disc tensile stress is adequate and compressive stress is small. When extension traction,with the increase of the pulling angle,spacing of intervertebral foramen becomes smaller,in which the C5- 6C6- 7part is the most; the intervertebral disc front spacing becomes larger,the back-end spacing becomes smaller,and nucleus moves forward. While the extension angle is less than 10 degree,the maximum compressive stress of each disc matrix and nucleus pulpous is very small without stress concentration. The uncovertebral joint spacing is the largest when 0 degree traction,which becomes smaller with the flexion,extension angle becomes larger. Conclusion The flexion position traction that is less than 15 degree is suggested in cervical radiculopathy patients treatment. 0 drgee traction is suggested in uncovertebral joint hyperplasia patients treatment. Less than 10 degree extension position traction is suggested in simple disc bulging with abnormal cervical curve treatment. It helps disc back satisfied,muscle tension relieved and abnormal curvature recovered.