Wang Zhikun, Zhang Xiansen, Li Zaixue, Feng Qingyu, Chen Jianting, Xie Wenwei
Department of Orthopedics, SSL Central Hospital of Dongguan City, Affiliated Shilong People's Hospital of Southern Medical University, Dongguan Guangdong, 523326, P.R.China.
Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou Guangdong, 510010, P.R.China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2021 Apr 15;35(4):471-476. doi: 10.7507/1002-1892.202011061.
To investigate the feasibility and mechanical properties of polymethyl methacrylate (PMMA) bone cement and allogeneic bone mixture to strengthen sheep vertebrae with osteoporotic compression fracture.
A total of 75 lumbar vertebrae (L -L ) of adult goats was harvested to prepare the osteoporotic vertebral body model by decalcification. The volume of vertebral body and the weight and bone density before and after decalcification were measured. And the failure strength, failure displacement, and stiffness were tested by using a mechanical tester. Then the vertebral compression fracture models were prepared and divided into 3 groups ( =25). The vertebral bodies were injected with allogeneic bone in group A, PMMA bone cement in group B, and mixture of allogeneic bone and PMMA bone cement in a ratio of 1∶1 in group C. After CT observation of the implant distribution in the vertebral body, the failure strength, failure displacement, and stiffness of the vertebral body were measured again.
There was no significant difference in weight, bone density, and volume of vertebral bodies before decalcification between groups ( >0.05). After decalcification, there was no significant difference in bone density, decreasing rate, and weight between groups ( >0.05). There were significant differences in vertebral body weight and bone mineral density between pre- and post-decalcification in 3 groups ( <0.05). CT showed that the implants in each group were evenly distributed in the vertebral body with no leakage. Before fracture, the differences in vertebral body failure strength, failure displacement, and stiffness between groups were not significant ( >0.05). After augmentation, the failure displacement of group A was significantly greater than that of groups B and C, and the failure strength and stiffness were less than those of groups B and C, the failure displacement of group C was greater than that of group B, and the failure strength and stiffness were less than those of group B, the differences between groups were significant ( <0.05). Except for the failure strength of group A ( >0.05), the differences in the failure strength, failure displacement, and stiffness before fracture and after augmentation in the other groups were significant ( <0.05).
The mixture of allogeneic bone and PMMA bone cement in a ratio of 1∶1 can improve the strength of the vertebral body of sheep osteoporotic compression fractures and restore the initial stiffness of the vertebral body. It has good mechanical properties and can be used as one of the filling materials in percutaneous vertebroplasty.
探讨聚甲基丙烯酸甲酯（PMMA）骨水泥与同种异体骨混合强化骨质疏松性压缩骨折绵羊椎体的可行性及力学性能。
取75个成年山羊腰椎（L -L ），经脱钙制备骨质疏松椎体模型。测量椎体脱钙前后的体积、重量及骨密度。用力学测试仪测试其破坏强度、破坏位移及刚度。然后制备椎体压缩骨折模型并分为3组（每组25个）。A组椎体注入同种异体骨，B组注入PMMA骨水泥，C组注入1∶1比例的同种异体骨与PMMA骨水泥混合物。CT观察植入物在椎体内的分布情况后，再次测量椎体的破坏强度、破坏位移及刚度。
各组脱钙前椎体的重量、骨密度及体积差异无统计学意义（P>0.05）。脱钙后，各组骨密度、降低率及重量差异无统计学意义（P>0.05）。3组脱钙前后椎体重量及骨密度差异有统计学意义（P<0.05）。CT显示各组植入物在椎体内分布均匀，无渗漏。骨折前，各组椎体破坏强度、破坏位移及刚度差异无统计学意义（P>0.05）。强化后，A组破坏位移显著大于B组和C组，破坏强度及刚度小于B组和C组；C组破坏位移大于B组，破坏强度及刚度小于B组，组间差异有统计学意义（P<0.05）。除A组破坏强度差异无统计学意义（P>0.05）外，其他各组骨折前与强化后的破坏强度、破坏位移及刚度差异有统计学意义（P<0.05）。
1∶1比例的同种异体骨与PMMA骨水泥混合物可提高绵羊骨质疏松性压缩骨折椎体强度，恢复椎体初始刚度，力学性能良好，可作为经皮椎体成形术的填充材料之一。
