棘突间撑开融合装置融合效能的生物力学与组织学评价初步研究

Preliminary biomechanical analysis and histological evaluation of fusion capacity after the implantation of interspinous distraction fusion device

目的通过生物力学和组织学评价分析棘突间撑开融合(ISDF)装置在腰椎退行性疾病治疗中的棘突间融合能力。方法实验动物通过首都医科大学附属北京友谊医院科研实验动物中心购置,周龄8~9周,平均体重25 kg。15只小型猪采用抽签法随机分为假手术组、减压术组及ISDF固定减压术组3组,每组5只。假手术组单纯切开显露椎板缝合,减压术组接受单侧半椎板减压,ISDF固定减压术组实施单侧半椎板减压+ISDF固定。ISDF装置植骨槽填充单纯的骨移植材料。实验动物饲养6个月后处死,获得相应的腰椎标本。将样本固定在脊柱测试系统上,通过多轴机器人系统测试手术节段屈伸、侧弯和旋转的活动度。ISDF固定术组ISDF装置样本包埋后进行硬组织切片,用苏木精-伊红和甲苯胺蓝染色评估新骨形成情况。正态分布的计量资料以均数±标准差(±s)表示,组间比较采用独立样本t检验。结果与假手术组相比,减压术组椎间活动度前屈增加61.6%,后伸增加44.7%,左侧屈增加65.0%,右侧屈增加49.6%,左旋转增加83.8%,右旋转增加64.2%(P<0.05);与减压术组相比,ISDF固定减压术组的椎间活动度在前屈减少40.0%,后伸减少21.3%,左侧屈减少31.7%,右侧屈减少22.3%,左旋转减少28.7%,右旋转减少35.3%(P<0.05)。6个月后,ISDF固定减压术组样本的组织学切片染色可观察到明确的骨组织形成。甲苯胺蓝染色可见大面积新骨形成,苏木精-伊红染色可以观察到深染成骨细胞及骨组织。结论ISDF装置的置入为促进棘突间骨性融合提供了必要的稳定性,发生在ISDF装置植骨槽内的成骨为棘突间融合提供了可能性。

ObjectiveTo explore interspinous fusion capacity after interspinous distraction fusion(ISDF)device implantation,a preliminary biomechanical analysis and histological evaluation were performed.MethodsThe experimental animals were procured from the Science and Research Laboratory Animal Center of Beijing Friendship Hospital,Capital Medical University.The animals were 8-9 weeks old and with an average weight of 25 kg.15 mini-pigs were randomly divided into three groups,the sham operation group,the decompression group and the ISDF fixed decompression group,5 animals per group.The sham operation group was treated with simple incision and exposed lamina suture.The decompression group received unilateral decompression and the ISDF fixed decompression group experienced unilateral hemilaminectomy decompression and ISDF fixation.The graft-bed site was filled with purified bone graft material without any autograft bone.After 6 months feeding,all experimental animals were sacrificed and the corresponding lumbar vertebrae was obtained.The samples were fixed on the spinal test system and the range of motion of flexion-extension,lateral bending and rotation were tested through a multiaxial robotic system.The ISDF device samples were embedded for hard tissue sections and stained with hematoxylin-eosin and toluidine blue to assess new bone formation.Normally distributed measurement data were expressed as mean±standard deviation(±s),and independent samples t-test were used for comparisons between groups.ResultsIn comparison to the sham operation group,the decompression group exhibited a statistically significant increase in intervertebral mobility,with an average of 61.6%in anterior flexion,44.7%in posterior extension,65.0%in left lateral flexion,49.6%in right lateral flexion,83.8%in left rotation,and 64.2%in right rotation(P<0.05).In comparison to the decompression group,the ISDF fixed decompression group exhibited a statistically significant decrease in intervertebral mobility,with an average of 40.0%in anterior flexion,21.3%in posterior extension,31.7%in left lateral flexion,22.3%in right lateral flexion,28.7%in left rotation,and 35.3%in right rotation(P<0.05).Well-defined bone tissue can be observed in the histological images of ISDF fixed decompression group samples after 6 months.In the histological part,toluidine blue staining showed extensive new bone formation.The hyperchromatic osteoblasts cells and density bone tissue can be observed in hematoxylin-eosin staining slides.ConclusionsThe implantation of ISDF provide the necessary stabilization for promoting fusion.The osteogenesis that occurs within graft-bed site of the ISDF device offers the possibility of interspinous fusion.