中文摘要：

目的探讨丝素蛋白／磷酸钙骨水泥（SF／CPC）作为椎体骨缺损强化剂的可行性。方法24只成年雌性绵羊经侧方腹膜后入路在L3、L4、L5椎体建立骨缺损模型，随机顺序植入CPC、SF／CPC、聚甲基丙烯酸甲酯（PMMA）3种材料。于术后1、6个月各处死12只羊，从中随机选择4只，将其标本制成不脱钙切片，苦味酸-品红染色后对材料-骨界面进行组织学观察，并对CPC、SF／CPC两组的新骨形成和残留水泥进行定量比较。另外8只以L6椎体作为对照组，进行生物力学检测，测量并比较不同组间的单椎体的抗压强度和刚度。结果组织学观察显示：1个月时，CPC组和SF／CPC组的材料和骨形成直接结合，吸收成骨较为表浅；6个月时，CPC组的吸收成骨仍仅限于材料表面，而SF／CPC组骨长入明显、材料吸收加快。PMMA组的材料和骨结合疏松，部分界面之间存在膜性结构，材料表面无新骨形成，6个月和1个月相比变化不明显。组织学定量分析显示：6个月时．SF／CPC组的新骨生成多于CPC组，残留水泥少于CPC组，差异有统计学意义（P〈0．05）．生物力学测试表明：6个月时，CPC组和SF／CPC组椎体的抗压强度和刚度均较1个月时有提升，而PMMA组则下降，差异均有统计学意义（P〈0．05）。SF／CPC组和PMMA组椎体在两个时间点的抗压强度和刚度与正常椎体相比，差异均无统计学意义（P〉0．05）。结论SF／CPC具有良好的生物活性和骨传导性以及相对较快的降解-成骨速度，并在此过程中很好地维持了椎体的力学性能，有望取代PMMA成为一种新的活性椎体强化剂。

英文摘要：

Objective To study the feasibility of using silk fibroin/calcium phosphate cement （SF/ CPC） as an injeetable bone augmentation filling material for defected vertebrae in a sheep model. Methods Bone defects were created on L3, L4 and L5 in 24 adult sheep through the lateral retroperitoneum appnaeh. CPC, SF/CPC, and polymethylmethacrylate （PMMA） were injected into the defects of 3 vertebrae randomly. Twelve sheep were sacrificed at I and 6 months postoperation, respectively. Un-deealeified sections were made from the specimens fi＇om any 4 sheep and stained with Van-Gieson method. The microcosmic changes of bone-material interface were observed, and the amounts of new bone formation and cement residue were evaluated by hisiomorphometric analysis. Biomeehanical testing was performed on the specimens from the other 8 sheep, in which the strength and stiffness were determined on the vertebrae with L6 as a control. Results Histologically, CPC and SF/CPC contacted the bone directly but the absorption anti bone formation were superficial at one month postoperation. At 6 months postoperation, the absorption and bone formation were limited on the surface of CPC while the absorption and bone ingrowth were accelerated in SF/CPC group. In PMMA group where no significant changes were observed between 1 and 6 months, the material contacted the bone loosely, with membrane structure at partial interface but no new bone formation on the material. Histological quantitative analysis showed that new bone formation was significantly more and cement residue significantly less in SF/CPC group than in CPC group at 6 months （ P 〈 0.05）. Biomechanical testing showed that the compressive strength and stiffness were significantly enhanced at 6 months compared with one month in CPC and SF/CPC groups but significantly decreased in PMMA group （ P 〈 0. 05） . At the 2 time points, SF/CPC, PMMA and intact groups showed equivalent compressive strength and stiffness （ P 〉 0. 05） . Conclusions The SF/CPC composite has adva