Qian J, Yu S S, Liu J J, Chen L, Jing J H
Department of Orthopaedics, the Second Hospital of Anhui Medical University, Hefei 230601, China.
Zhonghua Yi Xue Za Zhi. 2018 Apr 3;98(13):1013-1018. doi: 10.3760/cma.j.issn.0376-2491.2018.13.012.
To analyze the biomechanics changes of lumbar spine caused by foraminotomy via percutaneous transforaminal endoscopic lumbar discectomy using the finite element method. Three healthy adult males (aged 35.6 to 42.3 years) without spinal diseases were enrolled in this study and 3D-CT scans were carried out to obtain the parameters of lumbar spine. Mimics software was applied to build a 3D finite element model of lumbar spine. Graded resections (1/4, 2/4, 3/4 and 4/4) of the left superior articular process of L(5) were done via percutaneous transforaminal endoscopic lumbar discectomy. Then, the pressure of the L(4/5) right facets, the pressure of the L(4/5) intervertebral disc and the motion of lumbar spine were recorded after simulating the normal flexion and extension, lateral flexion and rotation of the lumbar spine model during different resections. The data were compared among groups with analysis of variance. Comparing with the normal group, after 1/4 resection of the left superior articular process of L(5), the pressure of the L(4/5) right facets showed significant differences during left lateral flexion and rotation of lumbar spine (=8.823, 8.248, both <0.05); and the pressure of L(4/5) intervertebral disc also changed significantly during extension and right rotation of lumbar spine (=6.918, 6.438, both <0.05); the motion of lumbar spine showed obvious differences during right lateral flexion and rotation (=6.845, 7.772, 13.58, all <0.05). Comparing with the normal group, after 2/4 resection of the left superior articular process of L(5), the pressure of the L(4/5) right facets presented significant differences during all conditions (=5.670-17.830, all <0.05); the pressure of L(4/5) intervertebral disc changed significantly during flexion, extension, lateral flexion and right rotation (=5.260, 17.150, 5.727, 8.890, 15.660, all <0.05); the motion of lumbar spine also existed differences during extension, lateral flexion and rotation (=9.106, 5.431, 12.060, 11.160, 17.260, all <0.05). However, after 3/4 resections, the pressure of the L(4/5) right facets, the pressure of the L(4/5) intervertebral disc and the motion of lumbar spine presented differences during all conditions when compared with those in normal group (=6.303-25.48, all <0.05). After 4/4 resections, the pressure of the L(4/5) right facets and the pressure of the L(4/5) intervertebral disc and the motion of lumbar spine showed significant differences during all conditions when compared with those in normal group (=8.065-45.70, all <0.05). The biomechanics and the stability of lumbar spine changed partly after 1/4 resection of the superior articular process and obviously after more than 2/4 is resected. The superior articular process should be paid more attention during foraminotomy via percutaneous transforaminal endoscopic lumbar discectomy.
采用有限元方法分析经皮椎间孔镜下腰椎间盘切除术行椎间孔切开术引起的腰椎生物力学变化。本研究纳入3例无脊柱疾病的健康成年男性（年龄35.6至42.3岁），行3D-CT扫描以获取腰椎参数。应用Mimics软件构建腰椎三维有限元模型。经皮椎间孔镜下腰椎间盘切除术对L5左侧上关节突进行分级切除（1/4、2/4、3/4和4/4）。然后，在模拟腰椎模型不同切除情况下的正常屈伸、侧屈和旋转后，记录L4/5右侧小关节压力、L4/5椎间盘压力及腰椎运动情况。采用方差分析对各组数据进行比较。与正常组相比，L5左侧上关节突切除1/4后，腰椎左侧侧屈和旋转时L4/5右侧小关节压力有显著差异（F=8.823、8.248，均<0.05）；腰椎伸展和右旋时L4/5椎间盘压力也有显著变化（F=6.918、6.438，均<0.05）；腰椎右侧侧屈和旋转时腰椎运动有明显差异（F=6.845、7.772、13.58，均<0.05）。与正常组相比，L5左侧上关节突切除2/4后，所有情况下L4/5右侧小关节压力均有显著差异（F=5.670 - 17.830，均<0.05）；腰椎屈伸、侧屈和右旋时L4/5椎间盘压力有显著变化（F=5.260、17.150、5.727、8.890、15.660，均<0.05）；腰椎伸展、侧屈和旋转时运动也有差异（F=9.106、5.431、12.060、11.160、17.260，均<0.05）。然而，切除3/4后，与正常组相比，L4/5右侧小关节压力、L4/5椎间盘压力及腰椎运动在所有情况下均有差异（F=6.303 - 25.48，均<0.05）。切除4/4后，与正常组相比，L4/5右侧小关节压力、L4/5椎间盘压力及腰椎运动在所有情况下均有显著差异（F=8.065 - 45.70，均<0.05）。上关节突切除1/4后腰椎生物力学和稳定性部分改变，切除超过2/4后明显改变。经皮椎间孔镜下腰椎间盘切除术行椎间孔切开术时应更关注上关节突。
