Zhuang Jinpeng, Jing Yongbin, Wang Yaming, Zhang Jinghuai, Xie Huanxin, Yan Jinglong
Department of Orthopedic Surgery, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, 150081, People's Republic of China.
Institute for Advanced Ceramics, Harbin Institute of Technology, Harbin, 150001, People's Republic of China.
J Orthop Surg Res. 2016 Mar 14;11:30. doi: 10.1186/s13018-016-0362-5.
Degraded and osteogenic property of coated magnesium alloy was evaluated for the fracture fixation in rabbits.
Magnesium alloy AZ31 with a different coating thickness by microarc oxidation was used, and the bilateral radial fracture model was created by the bite bone clamp. Thirty-six New Zealand white rabbits in weight of 2.5~3.0 kg were randomly divided into A, B, and C groups at four time points and other 3 rabbits as the control group without magnesium alloy. Coated magnesium alloy AZ31 was implanted on the fracture and fixed with silk thread. Indexes such as general observation, histology, X-ray, hematology, and mechanical properties were observed and detected at 2nd, 4th, 8th, and 12th week after implantation.
Fracture in each rabbit was healed at 12th week after implantation. Among the three groups, the best results of general observation, histology, and X-ray appeared in A group without coating. However, A group showed the worst results from the perspective of mechanical properties about tensile strength and flexural strength, which failed to reach that of the natural bone at the 12th week. Comprehensive results displayed that C group with 20-μm coating was better than others in mechanical properties, while there is no difference between B and C groups in hematology.
Degradation rate is inversely proportional to the coating thickness. And magnesium alloy with a 20-μm coating is more suitable for the fracture fixation.
评估涂层镁合金在兔骨折固定中的降解及成骨性能。
采用微弧氧化法制备不同涂层厚度的镁合金AZ31，用咬骨钳建立双侧桡骨骨折模型。将36只体重2.5~3.0 kg的新西兰白兔在四个时间点随机分为A、B、C组，另取3只兔作为无镁合金的对照组。将涂层镁合金AZ31植入骨折处并用丝线固定。在植入后第2、4、8和12周观察并检测一般观察、组织学、X线、血液学和力学性能等指标。
植入后第12周每只兔的骨折均愈合。三组中，一般观察、组织学和X线检查结果最好的是无涂层的A组。然而，从拉伸强度和弯曲强度等力学性能角度来看，A组在第12周时最差，未达到天然骨的水平。综合结果显示，涂层厚度为20μm的C组力学性能优于其他组，而B组和C组在血液学方面无差异。
降解速率与涂层厚度成反比。涂层厚度为20μm的镁合金更适合骨折固定。
