Comparative Study about Degradation of High-purity Magnesium Screw in Intact Femoral Intracondyle and in Fixation of Femoral Intracondylar Fracture  

作　　者：Pei Han Pengfei Cheng Changli Zhao Shaoxiang Zhang Runhua Zhou Xiaonong Zhang Yimin Chai 

机构地区：[1]Orthopaedic Department, ShanghaiJiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China [2]State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, ShanghaiJiao Tong University, Shanghai 200240, China [3]Suzhou Origin Medical Technology Co. Ltd., Suzhou 215513, China

出　　处：《Journal of Materials Science & Technology》2017年第3期305-310,共6页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China (Nos. 51271117 and 81371935);the Biomedical Program of Science and Technology Innovation Project supported by Shanghai (Nos. 14441901800 and 14441901802)

摘　　要：Bone screws encounter complex mechanical environment in fracture fixation of weight-bearing bone.In the present study, high-purity magnesium（HP Mg） screws were applied in fixation of rabbit femoral intracondylar fracture with 3 mm gap. In the control group, HP Mg screws of the same design were implanted at corresponding position of contralateral leg. At 4, 8 and 16 weeks after surgery, retrieved femurs went through micro-computed tomography（micro-CT） scanning and hard tissue processing. Under mechanical stress involved in fracture fixation, bending of screw bolt was observed at the portion exposed to facture gap at 4 weeks. Then local corrosion at the same portion was detected 16 weeks after surgery,which indicated the accumulation effect of mechanical stress on Mg corrosion. HP Mg screws in the fracture group had no significant difference with the control group in screw volume, surface area, surfaceto-volume ratio（S/V）. And peri-implant bone volume/tissues volume（BV/TV） and bone volume density（BMD） in the fracture group was comparable to that in the control group. Furthermore, histological analysis showed new formed bone tissues in fracture gap and fracture healing 16 weeks after surgery. Under mechanical stress, HP Mg screw suffered bolt bending and local corrosion at the portion exposed to fracture gap. But it had no influence on the integral corrosion behaviors, osseointegration of HP Mg screw and the fracture healing. Therefore, HP Mg screws possessed good potential in fracture fixation of weightbearing bones.Bone screws encounter complex mechanical environment in fracture fixation of weight-bearing bone.In the present study, high-purity magnesium（HP Mg） screws were applied in fixation of rabbit femoral intracondylar fracture with 3 mm gap. In the control group, HP Mg screws of the same design were implanted at corresponding position of contralateral leg. At 4, 8 and 16 weeks after surgery, retrieved femurs went through micro-computed tomography（micro-CT） scanning and hard tissue processing. Under mechanical stress involved in fracture fixation, bending of screw bolt was observed at the portion exposed to facture gap at 4 weeks. Then local corrosion at the same portion was detected 16 weeks after surgery,which indicated the accumulation effect of mechanical stress on Mg corrosion. HP Mg screws in the fracture group had no significant difference with the control group in screw volume, surface area, surfaceto-volume ratio（S/V）. And peri-implant bone volume/tissues volume（BV/TV） and bone volume density（BMD） in the fracture group was comparable to that in the control group. Furthermore, histological analysis showed new formed bone tissues in fracture gap and fracture healing 16 weeks after surgery. Under mechanical stress, HP Mg screw suffered bolt bending and local corrosion at the portion exposed to fracture gap. But it had no influence on the integral corrosion behaviors, osseointegration of HP Mg screw and the fracture healing. Therefore, HP Mg screws possessed good potential in fracture fixation of weightbearing bones.

关 键 词：High-purity magnesium Fracture fixation Femoral intracondylar Corrosion Osseointegration 

分 类 号：TG146.22[一般工业技术—材料科学与工程] S857.164[金属学及工艺—金属材料]