【作者】 顾勇；

【导师】 陈亮；

【作者基本信息】 苏州大学 ， 骨科学， 2009， 硕士

【摘要】 【目的】建立一种绵羊前路腰椎体间融合模型;评估不同植骨材料的成骨效果,探讨可注射磷酸钙/丝素蛋白/人重组骨形态发生蛋白-2 (calcium phosphate cement/silk fibroin/recombinant human bone morphogenetic protein-2, CPC/SF/ rhBMP-2)复合人工骨应用于椎体间融合的可能性。【方法】16只健康成年绵羊被随机分为两组,均经左侧腹膜外入路,暴露L1/2、L3/4和L5/6椎间盘,在其中点制成深度为12mm,直径为7.0mm的垂直于矢状面的孔洞,不穿透对侧纤维环,完全清除髓核组织,充分处理终板至渗血,建立前路椎体间融合模型。每只绵羊的三个腰椎椎间隙孔洞随机植入下列四种材料的三种:CPC/SF、CPC/rhBMP-2、CPC/SF/rhBMP-2或自体松质髂骨。分别于术后3、6个月处死两组绵羊,通过大体观察、手触检测、CT扫描、非破坏性生物力学测试、不脱钙组织学以及组织形态学方法观察和分析脊柱融合状况。【结果】各种人工骨注射过程流畅,自体髂骨不能经注射器注入。术后腰椎标本完整性均良好,稳定性可,无附件等组织破坏,对侧纤维环均没有穿破,钻孔侧椎旁无渗漏。手触检查结果表明:术后3月时,CPC/SF、CPC/rhBMP-2、CPC/SF/rhBMP-2以及自体松质髂骨植骨融合率分别为0(0/6)、16.67%(1/6)、33.33%(2/6)和50%(3/6);而术后6月时,融合率分别为0(0/6)、33.33%(2/6)、50%(3/6)以及50%(3/6)。非破坏性生物力学测试显示:术后3月时,屈曲、后伸、左侧屈以及右侧屈四个施力方向的融合强度自体髂骨> CPC/SF/rhBMP-2>CPC/rhBMP-2>CPC/SF,差异有统计学意义(P<0.05),而CPC/SF与完整运动节段相比,差异没有统计学意义(P>0.05);术后6月时,CPC/SF/rhBMP-2与自体髂骨表现出相近的力学强度(P>0.05),两者在四个方向的融合强度>CPC/rhBMP-2>CPC/SF,差异有统计学意义(P<0.05)。组织形态计量学表明:术后3月时,新骨生成量自体髂骨>CPC/SF/rhBMP-2>CPC/rhBMP-2>CPC/SF,差异有统计学意义(P<0.05);而钙磷残留量CPC/SF> CPC/rhBMP-2>CPC/SF/rhBMP-2,差异也有统计学意义(P<0.05);术后6月时,CPC/SF/rhBMP-2成骨能力与自体髂骨相当(P>0.05),二者新骨生成量> CPC/rhBMP-2>CPC/SF,差异有统计学意义(P<0.05);而钙磷残留量CPC/SF> CPC/rhBMP-2>CPC/SF/rhBMP-2,差异也有统计学意义(P<0.05)。【结论】腰椎间隙孔洞深度为12mm,直径为7.0mm的绵羊腰椎体间融合模型是一种理想的动物模型,可以用来评估可注射骨移植替代材料的成骨性能。CPC/SF/rhBMP-2复合人工骨具有合适的注射性能和凝固时间,固化后具有稳定的力学支撑能力,同时具备骨传导性和骨诱导性,降解与成骨能力相匹配,最终获得脊柱骨性融合。更多还原

【Abstract】 [Objective] To establish an anterior interbody fusion model on sheep lumbar spine; to evaluate the osteogenic capacity of different material fillings and disscuss the feasibility of injectable calcium phosphate cement/silk fibroin/recombinant human bone morphogenetic protein-2 (CPC/SF/rhBMP-2) composite inplated as a novel bone subsitute on spinal fusion.[Methods] Sixteen sheep were randomly divided into two groups. Eight sheep in each group were operated on left retroperitoneum approach and intervertebral discs of L1/2, L3/4 and L5/6 were exposed. Cavities were made on the midpoint of disc space perpendicular to sagittal plane, with 12 mm in depth and 7 mm in diameter. The opposite side of annular fibrosus was kept intact, nucleus pulposus was cleared completely, and endplate was processed to capillary hemorrhage. Three fusion sites in each animal were randomly assigned three of four treatments: calcium phosphate/silk fibroin composite (CPC/SF), calcium phosphate/recombinant human bone morphogenetic protein-2 composite (CPC/rhBMP-2), CPC/SF/rhBMP-2, or autogeous iliac crest cancellous bone. Sheep of the two groups were killed at 3 and 6 months postoperation respectively. The fusion sites were observed and analyzed by manual palpation, CT scan, undestructive biomechanic test, undecalcified histology, and histomorphology.[Results] All the bone subsitutes were injected succesfully while the iliac cancellous bone couldn’t be injected by syringe. The structures of all the lumbar spine specimens were presvered integrity with favourable stability and without appendix destroyed. The opposite side of annular fibrosus was kept intact and no leakage of bone subsitutes was observed in the drilling side. The fusion rates of CPC/SF, CPC/rhBMP-2, CPC/SF/rhBMP-2 and autogenous iliac cancellous bone assessed by manual palpation were 0 (0/6), 16.67% (1/6), 33.33% (2/6) and 50% (3/6) at 3 months postoperation, respectively. The fusion rates were 0 (0/6), 33.33% (2/6), 50% (3/6) and 50% (3/6) at 6 months, respectively. The fusion stiffness of all directions among the four materials had significant differences (P<0.05) at 3 months postoperation, with iliac bone the greatest, CPC/SF/rhBMP-2 next, then CPC/rhBMP-2, and CPC/SF the smallest. Statistical differences were not detected between CPC/SF and intact specimen (P>0.05). It revealed similar stiffness between iliac bone and CPC/SF/rhBMP-2 at 6 months after surgery (P>0.05). The similar stiffness of the two materials were greater than CPC/rhBMP-2 and CPC/SF (P<0.05). The new bone formation among the four materials had significant differences (P<0.05) at 3 months postoperation, with iliac bone at most, CPC/SF/rhBMP-2 next, then CPC/rhBMP-2, and CPC/SF the least. The residual volume of calcium phosphate has significant differences (P<0.05) among the three bone subsitutes, with CPC/SF at most, CPC/rhBMP-2 next, and CPC/SF/rhBMP-2 the least. It revealed almost new bone formation between iliac bone and CPC/SF/rhBMP-2 at 6 months after surgery (P>0.05). The similar bone formation volume of the two materials were more than CPC/rhBMP-2 and CPC/SF (P<0.05). It showed the same trendency about residual volume of calcium phosphate with at 3 months postoperation.[Conclusion] The sheep anterior lumbar interbody fusion model, of which the cavities are made on sheep intervertebral space with 12 mm in depth and 7 mm in diameter, is an ideal fusion model to evaluate the capability of bone formation for injectable bone subsitues. The CPC/SF/rhBMP-2 composite has suitable injectable nature, cogulation time, stable supporting mechanics after cogulation, excellent osteoconduction and osteoinduction, and matching degradation and osteogenesis ability. It is a kind of ideal bone subsitute in spinal fusion.更多还原