短节段跨伤椎固定横连对椎弓根皮质劈裂稳定性的生物力学研究

发布时间：2018-08-31 12:45

【摘要】：本研究通过生物力学测试在成年绵羊胸腰椎椎弓根劈裂模型下探讨横连位置及数目对脊柱内固定的影响进行评价。进而通过附加横连弥补椎弓根螺钉打劈椎弓根皮质引起的失稳。通过人工筛查以及X线透视排除病变,选用正常新鲜绵羊胸腰椎标本(T13~L3节段)60具,建立L1椎体压缩骨折模型,将其随机分成A、B、C、D、E、F,共6组。T14,L2双侧椎弓根置入螺钉,连接钛棒固定T14-L2节段。然后对B、C、D、E、F组在T14椎体右侧的椎弓根行外侧1/4骨皮质切除,即为置入的螺钉通道的外侧1/4(长为10mm,宽为5mm),直至露出螺钉外侧螺纹,并清除螺纹内骨质,作为椎弓根皮质劈裂椎体骨折模型。最后各组采用不同的横连数目固定:A组(0个横连,Intact)、B组(0个横连,NCL),C组(1个横连,连接棒的1/2处,MCL),D组(1个横连,连接棒的1/3处,靠近T14椎体,PCL),E组(1个横连,连接棒的2/3处,远离T14椎体,DCL),F组(2个横连,连接棒的1/3和2/3处,TCL)。各组标本然后在HY-3080微机控制电子万能材料试验机和HY-1000NM微机控制扭转试验机上以频率为1.5Hz的载荷对标本进行10000次疲劳试验,分别测量疲劳试验后6组标本的轴向压缩刚度,前屈、后伸、左侧弯、右侧弯、左轴向旋转及右轴向旋转6个方向的活动范围(ROM)及T14椎体椎弓根劈裂侧螺钉最大拔出力的大小,比较6组的差异。6组标本的轴向压缩刚度比较:A、C、D、E、F 5组的模型刚度明显高于B组(P0.05);C、D、E三组模型刚度差异与F组相比无统计学意义(P0.05);C、D、E三组刚度差异均无统计学意义(P0.05);F组模型刚度均小于A组(P0.05)。6组标本的活动度(ROM)比较:B组模型在屈伸(围绕冠状轴)、侧弯(围绕矢状轴)、旋转(围绕垂直轴)6个方向的运动范围(ROM)均明显高于A、C、D、E、F 5组(P0.05);C、D、E三组模型在旋转2个方向的运动范围(ROM)均大于F组(P0.05);在屈伸、侧弯4个方向的运动范围(ROM)与F组相比差异无统计学意义;C、D、E三组活动度差异均无统计学意义(P0.05);F组模型在屈伸、侧弯、旋转6个方向的运动范围(ROM)与A组比较差异均无统计学意义(P0.05)。6组标本的螺钉最大拔出力比较:A、C、D、E、F 5组的螺钉最大拔出力均高于B组(P0.05);C、D、E三组模型螺钉最大拔出力均小于F组(P0.05);C、D、E三组螺钉最大拔出力差异均无统计学意义(P0.05);F组模型螺钉最大拔出力均小于A组(P0.05)。椎弓根固定劈裂时,内固定稳定性明显下降。放置1个横连就可以提高内固定的稳定性,放置2个横连可近似达到椎弓根固定未劈裂时的稳定性。单个横连在短节段固定上不论在近端、远端还是中间的脊柱固定之间差异无统计学意义。
[Abstract]:In this study, biomechanical tests were carried out to evaluate the effect of the position and number of transverse connections on spinal internal fixation in adult sheep with thoracolumbar pedicle splitting model. Furthermore, the instability of pedicle cortex caused by pedicle screw was compensated by additional transverse connection. By artificial screening and X-ray fluoroscopy, 60 normal sheep thoracolumbar vertebrae specimens (T13~L3 segment) were selected to establish L1 vertebral compression fracture model. The model was randomly divided into 6 groups. Fix T14-L2 segment with titanium rod. Then the pedicle of the right side of the T14 vertebrae was treated with lateral 1 / 4 cortical resection of the pedicle in group B (10 mm long, wide 5mm), which was the lateral 1 / 4 of the inserted screw channel, until the lateral screw thread was exposed and the internal bone was cleared. As the pedicle cortical fracture model of vertebral body. Finally, each group was treated with different number of transverse connections: group A (0 transversals Intact) and group B (0 transverse connection NCL) and group C (1 horizontal connection, 1 / 2 MCL of connecting rod) group D (1 transverse connection, 1 / 3 of connecting rod, near T14 vertebral body PCL) group E (1 horizontal connection, 23 / 3 of connecting rod). Group F (two transverse connections, 1 / 3 and 2 / 3 of the connectors). The specimens were subjected to 10000 fatigue tests on HY-3080 microcomputer controlled electronic universal material testing machine and HY-1000NM microcomputer controlled torsion testing machine. The axial compression stiffness and forward flexion of 6 groups of specimens were measured after fatigue test. The maximum pull-out force of (ROM) and T14 pedicle split side screws in 6 directions of extension, left bending, right bending, left axial rotation and right axial rotation. Comparison of the axial compression stiffness of six groups of specimens the stiffness of the model of the group 1: C CX DX E 5 was significantly higher than that of the group B (P0.05). There was no significant difference in the stiffness of the three groups compared with the group F (P0.05). There was no significant difference in the stiffness of the three groups (P0.05) between the three groups. (P0.05) the stiffness of the three groups was not significantly different from that of the group F (P 0.05), and there was no significant difference in the stiffness of the three groups (P0.05). (ROM) comparison of the Model stiffness in Group A (P0.05) .6; the (ROM) of group B in flexion and extension (around coronal axis), lateral bend (around sagittal axis) and rotation (around vertical axis) in six directions were significantly higher than that in group A (P05). (P0.05) the motion range of group B was significantly higher than that of group A (P05) in the six directions of flexion and extension (around the coronal axis), lateral bend (around the sagittal axis) and rotation (around the vertical axis). The range of motion of the three groups in two directions of rotation was larger than that of group F (P0.05), and the range of motion in flexion and extension was higher than that in group F (P0.05). There was no significant difference in the range of motion in four directions of lateral curvature between (ROM) and group F. There was no significant difference in the range of motion between group C and group F (P0.05), and there was no significant difference in flexion and extension, lateral curvature of group F. There was no significant difference in the range of rotation between (ROM) and group A (P0.05) the maximum pull-out force of screw in group 1 was higher than that in group B (P0.05). The maximum pull-out force of screw in group F5 was higher than that in group B (P0.05). The maximum pull-out force of screw in group C was lower than that in group A (P0.05). There was no significant difference in the maximum pull-out force among the three groups (P0.05). The maximum pull-out force of the model screws in the F group was lower than that in the A group (P0.05). The stability of internal fixation decreased significantly when pedicle fixation split. The stability of internal fixation can be improved by placing one transverse connection, and the stability of pedicle fixation without splitting can be approximately achieved by placing two transverse connections. There was no significant difference in single transversal fixation between proximal distal and intermediate spinal fixation.
【学位授予单位】：河北北方学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R687.3

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