Abstract：
OBJECTIVE: To establish the finite element model of spinal canal reconstruction and internal fixation,analysis influence of spinal canal reconstruction and internal fixation on spinal stability,and verify the effectiveness and reliability of spinal canal reconstruction and internal fixation in spinal canal surgery.
METHODS: A 30-year-old male healthy volunteer with a height of 172 cm and weight of 75 kg was selected and his lumbar CT data were collected to establish a finite element model of normal lumbar L3-L5,and the results were compared with in vitro solid results and published finite element analysis results to verify the validity of the model. They were divided into normal group,laminectomy group and spinal canal reconstruction group according to different treatment methods. Under the same boundary fixation and physiological load conditions,six kinds of activities were performed,including forward bending,backward extension,left bending,right bending,left rotation and right rotation,and the changes of range of motion (ROM) of L3-L4,L4-L5 segments and overall maximum ROM of L3-L5 were analyzed under the six conditions.
RESULTS: The ROM displacement range of each segment of the constructed L3-L5 finite element model was consistent with the in vitro solid results and previous literature data,which confirms the validity of the model. In L3-L4,ROM of spinal canal reconstruction group was slightly increased than that of normal group during posterior extension(>5% difference),and ROM of other conditions was similar to that of normal group(<5% difference). ROM in laminectomy group was significantly increase than that in normal group and spinal canal reconstruction group under the condition of flexion,extension,left and right rotation. In L4-L5,ROM in spinal canal reconstruction group was similar to that in normal group(<5% difference),while ROM in laminectomy group was significantly higher than that in normal group and spinal canal reconstruction group(>5% difference). In the overall maximum ROM of L3-L5,spinal canal reconstruction group was only slightly higher than normal group under the condition of posterior extension(>5% difference),while laminectomy was significantly higher than normal group and spinal canal reconstruction group under the condition of anterior flexion,posterior extension,left and right rotation(>5% difference). The changes of each segment ROM and overall ROM of L3-L5 showed laminectomy group>spinal canal reconstruction group>normal group.
CONCLUSIONS: Laminectomy could seriously affect biomechanical stability of the spine,but application of spinal canal reconstruction and internal fixation could effectively reduce ROM displacement of the responsible segment of spine and maintain its biomechanical stability.
METHODS: A 30-year-old male healthy volunteer with a height of 172 cm and weight of 75 kg was selected and his lumbar CT data were collected to establish a finite element model of normal lumbar L3-L5,and the results were compared with in vitro solid results and published finite element analysis results to verify the validity of the model. They were divided into normal group,laminectomy group and spinal canal reconstruction group according to different treatment methods. Under the same boundary fixation and physiological load conditions,six kinds of activities were performed,including forward bending,backward extension,left bending,right bending,left rotation and right rotation,and the changes of range of motion (ROM) of L3-L4,L4-L5 segments and overall maximum ROM of L3-L5 were analyzed under the six conditions.
RESULTS: The ROM displacement range of each segment of the constructed L3-L5 finite element model was consistent with the in vitro solid results and previous literature data,which confirms the validity of the model. In L3-L4,ROM of spinal canal reconstruction group was slightly increased than that of normal group during posterior extension(>5% difference),and ROM of other conditions was similar to that of normal group(<5% difference). ROM in laminectomy group was significantly increase than that in normal group and spinal canal reconstruction group under the condition of flexion,extension,left and right rotation. In L4-L5,ROM in spinal canal reconstruction group was similar to that in normal group(<5% difference),while ROM in laminectomy group was significantly higher than that in normal group and spinal canal reconstruction group(>5% difference). In the overall maximum ROM of L3-L5,spinal canal reconstruction group was only slightly higher than normal group under the condition of posterior extension(>5% difference),while laminectomy was significantly higher than normal group and spinal canal reconstruction group under the condition of anterior flexion,posterior extension,left and right rotation(>5% difference). The changes of each segment ROM and overall ROM of L3-L5 showed laminectomy group>spinal canal reconstruction group>normal group.
CONCLUSIONS: Laminectomy could seriously affect biomechanical stability of the spine,but application of spinal canal reconstruction and internal fixation could effectively reduce ROM displacement of the responsible segment of spine and maintain its biomechanical stability.
摘要：
目的：建立椎管内固定重建的有限元模型，分析椎管重建和内固定对脊柱稳定性的影响，并验证椎管重建和内固定在椎管手术中的有效性和可靠性。
方法：选取一名身高172cm、体重75kg的30岁男性健康志愿者，收集其腰椎CT数据，建立正常腰椎L3-L5的有限元模型，并将结果与体外实体结果和发表的有限元分析结果进行比较，以验证模型的有效性。他们被分成正常组，椎板切除组和椎管重建组根据治疗方法不同。在相同的边界固定和生理负荷条件下，进行了六种活动，包括向前弯曲，向后扩展,左弯曲,右弯曲,左旋转和右旋转，在六种条件下，分析了L3-L4，L4-L5段的运动范围（ROM）和L3-L5的总体最大ROM的变化。
结果：构建的L3-L5有限元模型各段的ROM位移范围与体外固体结果和以前的文献数据一致，这证实了模型的有效性。在L3-L4中，椎管重建组的ROM在向后延伸期间比正常组略有增加（差异>5％），其他条件的ROM与正常组相似（差异<5％）。屈曲状态下椎板切除组的ROM较正常组及椎管重建组明显增加,扩展,左右旋转。在L4-L5中，椎管重建组的ROM与正常组相似（<5％差异），椎板切除组的ROM明显高于正常组和椎管重建组（差异>5％）。在L3-L5的总体最大ROM中,椎管重建组仅略高于正常组(>5%差异),前屈条件下椎板切除术明显高于正常组和椎管重建组,后延伸,左右旋转（>5％的差异）。L3-L5各节段ROM和整体ROM的变化显示椎板切除组>椎管重建组>正常组。
结论：椎板切除术会严重影响脊柱的生物力学稳定性，但椎管重建和内固定的应用可以有效减少脊柱负责段的ROM位移并保持其生物力学稳定性。
方法：选取一名身高172cm、体重75kg的30岁男性健康志愿者，收集其腰椎CT数据，建立正常腰椎L3-L5的有限元模型，并将结果与体外实体结果和发表的有限元分析结果进行比较，以验证模型的有效性。他们被分成正常组，椎板切除组和椎管重建组根据治疗方法不同。在相同的边界固定和生理负荷条件下，进行了六种活动，包括向前弯曲，向后扩展,左弯曲,右弯曲,左旋转和右旋转，在六种条件下，分析了L3-L4，L4-L5段的运动范围（ROM）和L3-L5的总体最大ROM的变化。
结果：构建的L3-L5有限元模型各段的ROM位移范围与体外固体结果和以前的文献数据一致，这证实了模型的有效性。在L3-L4中，椎管重建组的ROM在向后延伸期间比正常组略有增加（差异>5％），其他条件的ROM与正常组相似（差异<5％）。屈曲状态下椎板切除组的ROM较正常组及椎管重建组明显增加,扩展,左右旋转。在L4-L5中，椎管重建组的ROM与正常组相似（<5％差异），椎板切除组的ROM明显高于正常组和椎管重建组（差异>5％）。在L3-L5的总体最大ROM中,椎管重建组仅略高于正常组(>5%差异),前屈条件下椎板切除术明显高于正常组和椎管重建组,后延伸,左右旋转（>5％的差异）。L3-L5各节段ROM和整体ROM的变化显示椎板切除组>椎管重建组>正常组。
结论：椎板切除术会严重影响脊柱的生物力学稳定性，但椎管重建和内固定的应用可以有效减少脊柱负责段的ROM位移并保持其生物力学稳定性。
