内镜下经椎板间联合椎间孔入路减压治疗腰椎管狭窄症生物力学评价

Biomechanical Evaluation of Endoscopic Canal Decompression through Interlaminar Combined Foraminal Approach for Lumbar Spinal Stenosis

为了解决单纯应用椎板间或椎间孔入路,对于多部位、多因素、多层面致压的腰椎管狭窄症(lumbar spinal stenosis,LSS)病例,往往存在减压不彻底的情况,通过建立人体腰椎L4-L5节段有限元模型M0,构建精确的腰椎仿真模型,模拟经椎板间联合椎间孔入路减压,即Endo-LOVE(endoscopic LOVE decompression)联合PTED(percutaneous transforaminal endoscopic decompression)形成的环绕关节突周围减压M3模型,研究经椎板间联合椎间孔入路治疗腰椎管狭窄症术后生物力学变化及对责任节段稳定性影响。结果表明:M3处于前屈、后伸、左侧弯、右侧弯、左旋转、右旋转六种工况下时,其L4-L5责任节段活动度相对M0分别增加7.28%、11.29%、0.51%、0.27%、1.17%、0.51%,未发生节段失稳;M3处于前屈、后伸、左侧弯、右侧弯、左旋转、右旋转六种不同条件下时,其椎间盘Von Mises应力极值相对M0分别增加3.20%、9.51%、0.55%、0.10%、0.39%、-0.44%,未发生应力突变。可见在脊柱内镜下经椎板间联合椎间孔入路减压治疗腰椎管狭窄症时,其责任节段活动度ROM值和椎间盘Von Mises应力极值与正常的L4-L5节段相比,未见明显增加,生物力学稳定性较好,其可在保留关节突关节的情况下扩大椎管容积、充分减压,有效维持责任节段的稳定性。

In order to solve the simple application of interlaminar or intervertebral foramen approach,there is often incomplete de-compression for cases of lumbar spinal stenosis caused by multiple sites,multiple factors and multiple layers.By establishing the finite element model M0 of human lumbar L4-L5 segment,an accurate lumbar simulation model was used to investigate simulate the decom-pression of interlaminar combined with intervertebral foramen approach,that is,the M3 model of periarticular decompression formed by Endo-LOVE combined with PTED.The biomechanical changes and the stability of the responsible segment after the treatment of lumbar spinal stenosis by interlaminar combined with intervertebral foramen approach were studied.The results show that when M3 was in flex-ion,extension,left bending,right bending,left rotation and right rotation,the activity of L4-L5 responsibility segment increased by 7.28%,11.29%,0.51%,0.27%,1.17%and 0.51%respectively compared with M0,and no segment instability occurred.When M3 was under six different conditions of flexion,extension,left bending,right bending,left rotation and right rotation,the Von Mises stress extremum of the intervertebral disc increased by 3.20%,9.51%,0.55%,0.10%,0.39%and-0.44%respectively com-pared with M0,and no stress mutation occurred.It is concluded that in the treatment of lumbar spinal stenosis by endoscopic interlami-nar combined with intervertebral foramen decompression,the ROM value of the responsible segment and the extreme value of Von Mises stress of the intervertebral disc are not significantly increased compared with the normal L4-L5 segment,and the biomechanical stability is good.It can expand the spinal canal volume and fully decompress under the condition of retaining the facet joint,and effectively maintain the stability of the responsible segment.