3种不同内固定方式在上胸椎刚度的试验研究

Experimental study on rigidity effect of 3 kinds of different internal fixation at upper thoracic spine

目的比较上胸椎前路椎弓根钉板系统(ATPSPS)、后路椎弓根钉棒系统(PTPSRS)和前路普通椎体钉板系统(AVBSPS)在上胸椎的刚度。方法 12例防腐尸体标本分成3组,各组标本随机分配使用以上3种不同的内固定器械固定。测试各标本在原始状态下的轴向压缩、前屈、后伸、左右侧屈等5个方向的刚度。将所有标本模拟手术行T2椎体次全切除(损伤状态)后,再测试各标本在损伤状态下各方向的刚度。根据分组结果,选择相应的内固定系统进行安装固定,再测试各个方向上的刚度。结果在原始状态及损伤状态下,各组之间的各向刚度差异无统计学意义(P>0.05)。各标本行固定后,各组之间在各个方向上的刚度差异均有统计学意义(P<0.05)。ATPSPS组的前屈刚度大于其他两组,各组间比较差异有统计学意义(P<0.05)。PTPSRS组的轴向压缩刚度和后伸刚度大于其他两组,各组间比较差异有统计学意义(P<0.05)。AVBSPS组的侧屈刚度小于其他两组,差异有统计学意义(P<0.05),而其他两组差异无统计学意义(P>0.05)。结论ATPSPS在各方向上的刚度均高于AVBSPS,前屈刚度大于PTPSRS,而轴向压缩刚度和后伸刚度不及PTPSRS,左右侧屈刚度则与PTPSRS相当。

Objective To compare the rigidity at upper thoracic spine among the anterior transpedicular screw-plate system （ATPSPS）,posterior transpedicle screw-rod system （PTPSRS） and anterior vertebral body screw-plate system （AVBSPS）. Methods Twelve embalmed cadaver specimens were divided into three groups.The specimens in each group were randomly allocated to use the above 3 different internal fixation devices for conducting fixation.The stiffness of each specimen on the directions of axial compression,flexion and extension,and left and right lateral bending was detected under original status.All specimens conducted the simulated corpectomy of T2 （damage status）.Then the rigidity on various directions was re-detected on the damage status.The corresponding internal fixation system was selected for conducting the install and fixation according to the grouping results.The intra-group and inter- group rigiditieson different directions were compared among original status,damage status and after internal fixation. Results The rigidities on different directions under original and damage status had no statistical difference among various groups （ P 〈0.05）.After conducting fixation in each group,the rigidity after fixation on different directions had statistically significant difference among groups（ P 〈0.05）.The stiffness of anterior flexion in the ATPSPS group was greater than that in the other two groups （ P 〈0.05）.The rigidity of axial compression and extension in the PTPSRS group was greater than that in the other two groups,the difference among groups was statistically significant （ P 〈 0.05 ）.The stiffness of lateral bending in the AVBSPS group was smaller than that in the other two groups,the difference was significant （ P 〈0.05）,but the difference between the other two groups had no statistical significance （ P 〉0.05）. Conclusion The rigidity of ATPSPS in all directions is higher than that of AVBSPS.The anterior flexion rigidity is greater than PTPSRS,and the axial compression and extension rigidity are less than PTPSRS,but the lateral bending rigidity is equivalent to PTPSRS.