节段开窗髓核摘除对腰椎稳定性的影响

Stability of the Lumbar Spine After Segemental Fenestrations and Discectomies

目的本研究观察了腰椎椎板节段开窗髓核摘除对腰椎稳定性的影响。方法７具新鲜腰骶椎标本头尾端固定，模拟人体行屈曲、侧弯和旋转活动，随后顺序进行Ｌ３～Ｓ１椎板节段开窗及Ｌ４－５、Ｌ５Ｓ１髓核摘除，对比观察术前和多节段椎板双侧开窗及髓核摘除术后腰椎各节段在三维空间的位移变化。结果单纯多节段开窗后于屈曲活动时Ｌ４，５前后水平和轴向位移分别增加１８％和１６％，Ｌ５Ｓ１则分别增加１９％和４５％。椎板开窗加髓核摘除后，屈曲活动时Ｌ４，５前后水平和轴向位移分别增加２８％和７１％，Ｌ５Ｓ１则分别增加１４％和１６６％。统计学结果表明轴向位移差异有显著性意义，而在侧弯及旋转活动时差异均无显著性意义。腰椎的整体刚度术前、术后无明显变化。结论多节段椎板开窗髓核摘除对腰椎屈曲活动有影响，而对侧弯和旋转活动无明显影响。

Objective To investigate the effects of graded fenestrations and discectomies on the whole lumbar spine, including segment stiffness, horizontal sagittal and vertical translation Methods Seven fresh human cadaver specimens from lumbar 1 to sacrum were used in this study The graded fenestrations and discectomies consisted of L4-5 bilateral fenestrations, L5 S1 bilateral fenestration, L3-4 bilateral fenestration, L4-5 discectomy and L5 S1 discectomy Three kinds of loads, flexion, lateral bending and axial rotation (torsion), were applied The ranges of motion (ROM) were determined in threedimensions by the Elite system with two infraredcameras Results After the multiple fenestrations, the sagittal ranges of motion at L4-5 increased by 18%in AP, and 16%in vertical translation under the flexion loads At L5 S1, the motion iAuthor ncreased by 19%and 45%respectively After both fenestration and discectomies, the ranges of motion in the sagittal plane increased by 28%(horizontally) and 71%(vertically) at L4-5; 14%and 166%at L5 S1 The motion increases were statiscally significant (P< 005) in vertical translations However, after the graded surgeries, no significant motion were found in the lumbar segments during lateral bending as well as axial rotation Conclusion The present results demonstrate that multilevel fenestrations and discectomies affect lumbar spinal stability in flexion, but have not effect on the stability of the lumbar spine in lateral bending or axial rotation