重组人骨形态发生蛋白-2用于人工关节生物固定方法的研究

目的 探讨复合重组人骨形态发生蛋白-2(rhBMP2)植入体对骨-假体界面骨长入及结合强度的作用。方法将多孔金属表面植入体(PCA)与复合．rhBMP2的PCA植入体、HA涂层植入体及：PCA表面喷涂HA植入体植入犬皮质骨并综合运用X线摄片、软X线照相、不脱钙骨组织磨片、荧光显微镜检查、骨组织计量学分析及生物力学测定等方法对骨-植入体界面的骨长入及界面的结合强度进行了比较分析。结果术后软X线照相、组织学、骨组织计量学及生物力学比较分析显示复合rhBMP2的植入体在各时间组的新生骨形成率和界面剪切强度均优于其它各组;以4周时最为明显,且差异有非常显著意义。结论植入体复合rhBMP2后在促进早期骨-假体界面的骨长入和结合强度方面优于其它各种方法,有利于早期骨与假体间的结合和固定。

Experimental study of bone morphogenetic protein-2 in noncemented fixation of prosthesis

OBJECTIVE: To study on the method of combining rhBMP(2) with porous-coated implants, and compared the histological and biomechanical results of 4 types of implants by being inserted into the femur of canine. METHODS: 4 types of implants which are porous-coated implants (PCA), PCA implants combined with BMP, PCA implants coated with hydroxyapatite and HA coated cylindrical implants had been inserted into the femur of 16 canines. After 4, 8, 12 and 24 weeks the femur of the canines with the implants were retrieved. Bone ingrowth and shear strength of the interface was studied and analysed by the means of X-ray, soft X-ray, fluorescence tag, non-decalcification bone ground section, computer-aided image analysis procedure and biomechanical test. RESULTS: X-ray, soft X-ray, fluorescence tag, non-decalcification bone ground section and computer-aided image analysis procedure was used in histological study, and it showed that bony ingrowth into interface more than the other groups, even the maturation of newly formed bone. Non-decalcification bone ground section observation and computer aided image analysis showed the results: the new bone formation ratio of BMP group was 26.58% +/- 4.56% at 4 weeks post-implantation, which was much higher than the other groups, and there was significant difference between BMP group and each of the other group statistically (P < 0.05). Results of biomechanical study using push-out test showed that shear strength of each group appeared to rise with time. Shear strength of BMP group reached a high level at 4 weeks which was 18.94 +/- 5.11Mpa and almost twice of the other group, and there was also statistical difference between BMP group and each of the other group (P < 0.05). And the new bone formation ratio and shear strength of BMP group at 8, 12, 24 weeks post-implantation was still higher than the other group, but there was no statistically difference. CONCLUSIONS: Porous-coated implants combined with rhBMP can enhance bone ingrowth at bone-implant interface especially at the early period post-implantation. Porous-coated implants combined with rhBMP(2) can not only shorten the time of new bone formation and bone ingrowth but also enhance shear strength of bone-implant interface.