自体微小颗粒骨复合几丁糖修复椎板缺损的有限元分析

Finite element analysis of chitin in combination with autologous micromorselized bone in repairing bone defects

背景:几丁糖具备良好的支架作用,不仅能够弥补自体微小颗粒骨结构松散的不足,防止其向植骨床外周扩散,减少骨流失,同时伴随颗粒骨的成骨过程几丁糖还可随之降解。目的:探讨自体微小颗粒骨复合几丁糖修复椎板缺损的效果。方法:健康成年杂种犬20只,均制备椎板缺损。随机分为4组,复合组于椎板缺损区先充填一层几丁糖,再充填预制半干自体微小颗粒骨,后铺上一层几丁糖;自体微小颗粒骨组于椎板缺损区充填预制半干自体微小颗粒骨;几丁糖组于椎板缺损区充填几丁糖;空白组椎板缺损区不植入任何物质。术后8周,通过有限元方法对4组模型的应力和位移变化进行比较。结果与结论:关于位移值,几丁糖组>自体微小颗粒骨组>复合组,按照在一定载荷下位移越小刚度越大的理论,复合组模型刚度最大,自体微小颗粒骨组模型次之,几丁糖组模型刚度最小。提示几丁糖是微小颗粒骨的优良载体,自体微小颗粒骨复合几丁糖可有效修复椎板缺损,二者复合修复骨缺损的能力强于单纯微小颗粒骨。

BACKGROUND：Chitin functions as scaffold,which enhances structures of autologous micromorselized bone,prevents its distribution out of implant bone bed,reduces bone loss and degrades along micromorselized bone osteogenesis. OBJECTIVE：To explore the effects of autologous micromorselized bone in combination with chitin on repairing bone defects. METHODS：A total of 20 adult hybrid dogs were selected to establish models of the lamina in lumbar defect,and randomly divided into 4 groups. The combination group was implanted with autologous micromorselized bone and chitin; autologous micromorselized bone group was implanted with autologous micromorselized bone alone; chitin group was implanted with chitin alone,while blank control group was not implanted. The defect-repairing capability of the 4 treatments was assessed by three-dimensional finite element analysis at 8 weeks. RESULTS AND CONCLUSION：The displacement was greatest in chitin group,followed by autologous micromorselized bone group and then combination group. According to the theory that little displacement represents great rigidity,the rigidity of combination group was the greatest,followed by autologous micromorselized bone group and then chitin group. The chitin was a good carrier of the autologous micromorselized bone. The autologous micromorselized bone carried by chitin has more ability of repairing the bone defect compared with autologous micromorselized bone or chitin alone.