椎体成形术应用不同填充材料治疗骨质疏松椎体压缩性骨折的实验研究

Experimental study on the different injectable material in vertebroplasty

目的通过用不同填充材料对骨质疏松兔的椎体成形,进而对行椎体成形术后椎体的生物力学行动态观察,从而得出相关结论,为临床应用提供理论基础。方法选用5个月龄新西兰纯种雌性兔60只,随机选12只作为正常对照组(A组),剩余的48只使用去势法造成骨质疏松模型后随机分成四组,每组12只。模型对照组(B组);聚甲基丙酸甲酯骨水泥(PMMA)组(C组);自固化磷酸钙骨水泥(瑞邦骨泰,CPC)组(D组);骨形态发生蛋白(BMP)和CPC组(E组)。解剖出椎体后直视下穿刺,按组别分别注入上述填充剂,每只进行3个椎体(L4、L5、L6)。分别于术后当时、8周和16周取椎体标本,行X线检查,并测定不同时间点椎体的轴向抗压强度实验。结果①术后当时拍X线片,除PMMA组有1例可见骨水泥渗漏入椎管内,其余均未见渗漏。术后8周和16周分别拍X线片,可见手术椎体密度较其他椎体和模型对照组椎体均高,与正常对照组相仿。②术后当时C组的抗压强度明显高于其他组(P<0.01),A组抗压强度次之,高于B组(P<0.01)、D组(P<0.01)和E组(P<0.01),而B、D和E组间则差异无统计学意义(P>0.05)。术后8周,C组抗压强度有所下降与术后当时相比差异无统计学意义(P>0.05),D和E组抗压强度有所上升(P<0.01),B组抗压强度明显低于其他组(P<0.01)。术后16周,C组抗压强度持续下降与A、D和E组相比差异无统计学意义(P>0.05),D和E组抗压强度继续上升(P<0.01),B组抗压强度继续下降(P<0.01),与其他各组差异有统计学意义(P<0.01)。结论CPC和CPC/BMP虽然具有较好的生物学性能,并且有较为广阔的应用前景,但在临床实际应用中,尤其在治疗骨质疏松脊柱压缩骨折时,尚不能完全取代PMMA。

Objective To provide the theories clinical for the evidence application by dynamic observing biomechanics changes after vertebroplasty with the different filling materials in experimental osteoporotic rabbit. Methods Sixty New Zealand pure breed female rabbits of 5 months old was divide into five groups （A, B, C, D, E）, and each group had 12 rabbits.Group A was normal matched control and osteoporotic model were established by ovariectomy from B to E group.Implanted polymethylmethacrylate （PMMA） into the vertebral body of group C and calcium phosphate cement （CPC） into D group and CPC/BMP （bone morphogenic protein） into E group.Group B was the model matched control.When at 0.8 and 16 weeks old,the vertebral bodies implanted were tested by X ray and axial compressive testing.Results ① Bone cement leaked into vertebral canal in one case of group C after operation . The density of vertebral bodies in group C rabbits were higher than other groups by X ray analysis. ②At once after operation,the ultimate strength of vertebral bodies with implanted PMMA was higher than that others （P〈0.01） and group A was second place （B group P〈0.01,D group P〈0.01 ,E group P〈0.01 ）.There were no significant differences in B,D and E groups （P〉0.05）.After 8 weeks,the stiffness of group A became low,but have no the differences compare to before （P〉0.05）.The stiffness of group D and E became stronger （P〈0.01）. There was no significant differences in groups A and E （P〉0.05）and significant differences in groups A and D （P〈0.01）.When it came to 16 weeks,the stiffness of group A became lower （P〈0.01） and of group D and E became stronger （P〈0.01）.There were no significant differences in A,C,D and E groups （P〉0.05）.At the last was group B,there were very significant differences between B and other groups （P〈0.01）.Conclusion Although CPC and CPCdBMP have the good biology function,and have the vast and applied foreground,they could＇t replace the PMMA completely in clinically actually application, particularly at cure osteoporotic verterbral compression fractures.