第二代可吸收复合增强螺钉的力学性能生物降解和生物相容性实验研究

目的考察第二代可吸收复合增强螺钉的力学性能、生物降解和生物相容性。方法基于比格犬股骨骨折固定模型，连续观察12周，考察螺钉弯曲强度及其衰减率和生物吸收率（BAR），应用X线摄片、光镜和电镜观察骨折固定、骨小梁、骨痂等生长情况，并与第一代PDLLA螺钉比较。结果可吸收复合增强螺钉的弯曲强度在第2、4、8、12周时均高于第一代螺钉，弯曲强度衰减率均低于第一代螺钉；两种螺钉的弯曲强度术后前8周衰减较快，8周后衰减趋于平缓稳定，有利于骨折愈合和重塑改建；同时两种螺钉在各时间段的生物吸收率无差异；另外与第一代螺钉比较，第二代可吸收复合增强螺钉动物更早出现骨组织损伤后坏死组织，纤维组织增生、纤维性和骨性骨痂形成的变化，且纤维性和骨性骨痂形成更明显、典型，X光片也提示骨折临床愈合更早。结论第二代可吸收复合增强螺钉能更好的满足临床上对骨折内固定材料力学强度的要求，另外更有利于纤维性和骨性骨痂等骨组织愈合指标的形成。

Experimentation of the Second Absorbable Complex Enhancement Bolt for Mechanical Properties,Biodegradation and Biocompatibility

Objective To evaluated the mechanical properties, biodegradation and biocompatibility of the Second Absorbable Complex Enhancement Bolt by animal experiment. Methods Based on the Beagle dog model for fracture of femur in 12 weeks, the bolt＇s bending strength, and its rate of decay, and biological absorption rate （BAR） were observed, the fracture fixation, and the growth of bone trabe- cula and bony callus were determined by Using X ray, microscope and electron microscope, and the Second Absorbable Complex Enhancement Bolt was compared with the First one at bone formation in experimental animal. Results The bending strength of the Second Absorbable Complex Enhancement Bolt was stronger than the First one in the second, fourth, eighth, twelfth week, and its rate of decay was lower than the First one. Two Bolt＇s bending strength decreased fast in the forth eight weeks. After that time, the decay was stabilization, and its profited the union of fracture and remodeling. At the same time, Two Bolt＇s biological absorption rate had no difference in statistical significance. Compared with the first bolt, the second one was earlier to promote necrotic tissue, fibroplasias, thready and osseous callus formation, and the result of X ray was hinted that bone fracture was henosised earlier. Conclusion The Second Absorbable Complex Enhancement Bolt could satisfied the need of the mechanical strength for bone fracture＇s internal fixation materials, and profit the thready and osseous callus formation.