Vamvanij V, Ferrara L A, Hai Y, Zhao J, Kolata R, Yuan H A
Department of Orthopaedic Surgery, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Spine (Phila Pa 1976). 2001 Feb 1;26(3):E13-8. doi: 10.1097/00007632-200102010-00004.
An experimental study was performed using cadaveric lumbar spines to evaluate the effect of anteriorly or laterally placed interbody distraction implants on the alteration of spinal canal and neuroforaminal dimensions.
To quantify changes in the spinal canal and neuroforaminal dimensions using interbody fusion devices inserted at various configurations in cadaveric lumbar spines exhibiting degenerative spondylolisthesis.
Although several clinical studies have demonstrated successful treatment of degenerative spondylolisthesis with anterior interbody fusion, no study has shown the role of interbody distraction in improving lumbar spinal canal and foraminal stenosis.
Five fresh cadaver lumbar spines exhibiting a degenerative spondylolisthesis or retrospondylolisthesis were used for the study. Computed tomography scans of each specimen and a silicon mold of the left intervertebral foramens were repeated in a consistent manner after pure compressive load (150 lb) was applied to simulate physiologic load (intact case), after two BAK (Sulzer SpineTech Inc., Minneapolis, MN) distraction plugs were anteriorly inserted into the intervertebral disc space (anterior distraction cases), and after one long BAK cage was laterally inserted from the left side (lateral distraction case). The cross-sectional area of the spinal canal was measured from computed tomography images using National Institutes of Health image software (Bethesda, MD). The spinal canal volume was calculated using the cross-sectional area and total scan thickness. Left intervertebral foraminal volumes were calculated from the weight of the silicon mold injected into the foramen. Descriptive statistics and a Student's t test were used to detect statistical differences in the spinal canal and neuroforaminal volumes before and after interbody distraction.
The cross-sectional canal area was significantly increased after anterior distraction (35.11%) and lateral distraction (33.14%). The spinal canal volume was markedly increased with anterior distraction (19.92%) and lateral distraction (21.96%). Left foraminal volume was also enhanced by 40.25% for anterior distraction and 41.03% for lateral distraction.
Interbody distraction either by anteriorly inserted plugs or laterally inserted threaded cagescan immediately improve the narrowed canal area and increase spinal canal, as well as foraminal volume for lumbar degenerative spondylolisthesis or retro- spondylolisthesis.
采用尸体腰椎进行实验研究，以评估前路或侧方椎间撑开植入物对椎管和神经孔尺寸改变的影响。
使用在表现为退变性椎体滑脱的尸体腰椎中以各种构型插入的椎间融合装置，量化椎管和神经孔尺寸的变化。
尽管多项临床研究已证明前路椎间融合术成功治疗退变性椎体滑脱，但尚无研究表明椎间撑开在改善腰椎管和椎间孔狭窄方面的作用。
使用5具表现为退变性椎体滑脱或后滑脱的新鲜尸体腰椎进行研究。在施加纯压缩负荷（150磅）以模拟生理负荷（完整情况）后、在将两个BAK（苏尔寿脊柱技术公司，明尼阿波利斯，明尼苏达州）撑开塞从前路插入椎间盘间隙后（前路撑开情况）以及在将一个长BAK椎间融合器从左侧后路插入后（后路撑开情况），以一致的方式重复对每个标本进行计算机断层扫描以及对左侧椎间孔进行硅模制作。使用美国国立卫生研究院图像软件（贝塞斯达，马里兰州）从计算机断层扫描图像测量椎管的横截面积。使用横截面积和总扫描厚度计算椎管容积。根据注入椎间孔的硅模重量计算左侧椎间孔容积。采用描述性统计和学生t检验来检测椎间撑开前后椎管和神经孔容积的统计学差异。
前路撑开（35.11%）和后路撑开（33.14%）后，椎管横截面积显著增加。前路撑开（19.92%）和后路撑开（21.96%）后，椎管容积明显增加。前路撑开使左侧椎间孔容积增加40.25%，后路撑开使左侧椎间孔容积增加41.03%。
对于腰椎退变性椎体滑脱或后滑脱，通过前路插入塞子或后路插入带螺纹的融合器进行椎间撑开可立即改善狭窄的椎管面积，并增加椎管以及椎间孔容积。
