中华创伤骨科杂志
中華創傷骨科雜誌
중화창상골과잡지
CHINESE JOURNAL OF ORTHOPAEDIC TRAUMA
2014年
2期
151-155
,共5页
何仿%陆斌%李苏皖%林昊%周涛%张美超
何倣%陸斌%李囌皖%林昊%週濤%張美超
하방%륙빈%리소환%림호%주도%장미초
椎间盘%骨钉%有限元分析%置钉角度
椎間盤%骨釘%有限元分析%置釘角度
추간반%골정%유한원분석%치정각도
Intervertebral disk%Bone nails%Finite element analysis%Nailing angle
目的 比较不同置钉角度下腰骶椎椎弓根螺钉固定加椎间融合的有限元生物力学性能,以确定最佳的椎弓根螺钉固定角度. 方法 通过CT扫描、Mimics 13.0软件三维重建、Freeform6.0表面处理和Ansys10.0软件前处理等方法建立正常L4～S1节段有限元模型,并据此建立去除L5～S1椎间盘后椎弓根螺钉后路固定加椎间融合模型.根据不同置钉角度分为3组:模型1组:上、下位螺钉水平位内置0°,矢状位与终板平行;模型2组:上、下位螺钉水平位内置15°,矢状位与终板平行;模型3组:上位螺钉水平位内置0°、矢状位上翘15°,下位螺钉水平位内置0°、矢状位与终板平行.在这3组模型上分别加载5N·m的前屈、后伸、左侧弯和左旋转扭矩载荷,计算各组钉棒结构、椎间融合器及L4～S1的应力分布值. 结果 在前屈、后伸、左侧弯和左旋转4种状态下,模型2组的钉棒结构、椎间融合器、L4、L5和S1的最大应力值均处于最低水平,前屈时分别为2.96×107、5.65×106、5.76×106、8.06×106、8.51×106 N/m2,后伸时分别为2.98×107、6.08×106、6.49×106、8.63×106、9.17×106N/m2,侧弯时分别为3.06×107、9.71×106 、2.39×106、1.14×106、8.61×106 N/m2,左旋转时分别为2.96×107、1.00×106、5.76×106、8.06×106 、8.51×106 N/m2.除左旋转以外,其他3种静载状态下模型1组的钉棒结构和椎间融合器最大应力值均低于模型3组.结论 腰骶椎后路椎弓根螺钉固定加椎间融合时,矢状位与终板平行、水平位内倾一定角度有助于改善整体结构的应力水平,缓解螺钉和椎体结构的应力集中,从而避免断钉、断棒及螺钉松动的发生.
目的 比較不同置釘角度下腰骶椎椎弓根螺釘固定加椎間融閤的有限元生物力學性能,以確定最佳的椎弓根螺釘固定角度. 方法 通過CT掃描、Mimics 13.0軟件三維重建、Freeform6.0錶麵處理和Ansys10.0軟件前處理等方法建立正常L4～S1節段有限元模型,併據此建立去除L5～S1椎間盤後椎弓根螺釘後路固定加椎間融閤模型.根據不同置釘角度分為3組:模型1組:上、下位螺釘水平位內置0°,矢狀位與終闆平行;模型2組:上、下位螺釘水平位內置15°,矢狀位與終闆平行;模型3組:上位螺釘水平位內置0°、矢狀位上翹15°,下位螺釘水平位內置0°、矢狀位與終闆平行.在這3組模型上分彆加載5N·m的前屈、後伸、左側彎和左鏇轉扭矩載荷,計算各組釘棒結構、椎間融閤器及L4～S1的應力分佈值. 結果 在前屈、後伸、左側彎和左鏇轉4種狀態下,模型2組的釘棒結構、椎間融閤器、L4、L5和S1的最大應力值均處于最低水平,前屈時分彆為2.96×107、5.65×106、5.76×106、8.06×106、8.51×106 N/m2,後伸時分彆為2.98×107、6.08×106、6.49×106、8.63×106、9.17×106N/m2,側彎時分彆為3.06×107、9.71×106 、2.39×106、1.14×106、8.61×106 N/m2,左鏇轉時分彆為2.96×107、1.00×106、5.76×106、8.06×106 、8.51×106 N/m2.除左鏇轉以外,其他3種靜載狀態下模型1組的釘棒結構和椎間融閤器最大應力值均低于模型3組.結論 腰骶椎後路椎弓根螺釘固定加椎間融閤時,矢狀位與終闆平行、水平位內傾一定角度有助于改善整體結構的應力水平,緩解螺釘和椎體結構的應力集中,從而避免斷釘、斷棒及螺釘鬆動的髮生.
목적 비교불동치정각도하요저추추궁근라정고정가추간융합적유한원생물역학성능,이학정최가적추궁근라정고정각도. 방법 통과CT소묘、Mimics 13.0연건삼유중건、Freeform6.0표면처리화Ansys10.0연건전처리등방법건립정상L4～S1절단유한원모형,병거차건립거제L5～S1추간반후추궁근라정후로고정가추간융합모형.근거불동치정각도분위3조:모형1조:상、하위라정수평위내치0°,시상위여종판평행;모형2조:상、하위라정수평위내치15°,시상위여종판평행;모형3조:상위라정수평위내치0°、시상위상교15°,하위라정수평위내치0°、시상위여종판평행.재저3조모형상분별가재5N·m적전굴、후신、좌측만화좌선전뉴구재하,계산각조정봉결구、추간융합기급L4～S1적응력분포치. 결과 재전굴、후신、좌측만화좌선전4충상태하,모형2조적정봉결구、추간융합기、L4、L5화S1적최대응력치균처우최저수평,전굴시분별위2.96×107、5.65×106、5.76×106、8.06×106、8.51×106 N/m2,후신시분별위2.98×107、6.08×106、6.49×106、8.63×106、9.17×106N/m2,측만시분별위3.06×107、9.71×106 、2.39×106、1.14×106、8.61×106 N/m2,좌선전시분별위2.96×107、1.00×106、5.76×106、8.06×106 、8.51×106 N/m2.제좌선전이외,기타3충정재상태하모형1조적정봉결구화추간융합기최대응력치균저우모형3조.결론 요저추후로추궁근라정고정가추간융합시,시상위여종판평행、수평위내경일정각도유조우개선정체결구적응력수평,완해라정화추체결구적응력집중,종이피면단정、단봉급라정송동적발생.
Objective To determine the optimal nailing angle by comparing the biomechanical properties of different nailing angles in pedicle screw fixation plus intervertebral fusion in lumbosacral finite element models.Methods We established the finite element models of normal lumbosacral vertebral L4-S1 segments whose intervertebral disc of L5-S1 was removed using CT scan,three-dimensional reconstruction by software Mimics13.0,surface treatment by software Freeform6.0 and preprocessing bv software Ansys10.0,respectively.Fixation with posterior pedicle screws and intervertebral fusion was simulated in the finite element models.The models were divided into 3 groups according to the different nailing angles.Model 1:the screws above and below were inserted by angle of 0° transversely with the sagittal view parallel to the end plate.Model 2:the screws above and below were inserted by an angle of 15° transversely with the sagittal view parallel to the end plate.Model 3:the screw above was inserted by an angle of 0° transversely with the sagittal view uplifted by an angle of 15° while the screw below was inserted by an angle of 0° transversely with the sagittal view parallel to the end plate.Then all the models were subjected to torque loads of 5 N · m at anteflexion,posterior extension,left bending and left rotation respectively.The stress distributions of screw-rod system,cage,L4,L5 and S1 were analyzed and compared between the 3 groups.Results The stress distributions of screw-rod system,cage,L4,L5 and S1 at anteflexion,posterior extension,left bending and left rotation were the lowest in Model 2.The stress distributions of screw-rod system,cage,L4,L5 and S1 were respectively 2.96 × 107,5.65 × 106,5.76 × 106,8.06 × 106 and 8.51 × 106 N/m2 at anteflexion,respectively 2.98 × 107,6.08 × 106,6.49 × 106,8.63 × 106 and 9.17 × 106 N/m2 at posterior extension,respectively 3.06 × 107,9.71 × 106,2.39 × 106,1.14 × 106 and 8.61 × 106 N/m2 at left bending,and respectively 2.96 × 107,1.00 × 106,5.76 × 106,8.06 × 106 and 8.51 × 106 N/m2 at left rotation.The maximum stresses of screw-rod system and cage in Model 1 were lower than in Model 3 at anteflexion,posterior extension and left bending.Conclusion In fixation of lumbosacral posterior pedicle screw and intervertebral fusion,screws parallel to the end plate in the sagittal view and inserted by an inclined inward angle in the transverse position can improve the stress of the whole structure and ease the concentrated stress on screws and vertebral body,preventing breaking and loosening of screw-rod system.
