An experimental study on osseo-induction and biodegradation performances of three types of injectable and degradable calcium phosphate cement / 中华创伤骨科杂志

ABSTRACT

Objective To compare the osseo-induction and biodegradation performances of three types of injectable and degradable calcium phosphate cement (CPC) so as to find out a better bone substitute. Methods Three types of injectable and degradable CPC were respectively implanted into the bilateral tibias of 24 New Zealand rabbits pure CPC (Group A), CPC added with Zinc and Strontiumions (Group B), and CPC with composite rhBMP-2 (Group C) . Their systematic and local reactions in implanted region were closely observed. The degra- dation and osseo-induction performances were compared macroscopically, microscopically and by CT scan to find out the one that could best meet clinical needs. Tissue slices were sampled and photographed four, eight and 16 weeks after operation. Five photographs were selected in each group and at each time points for computer software (Image Pro Plus 5.1) processing to calculate the percentages of bone in the images of postoperative slices. Results In Groups A and B, new bone was found to form slowly and little by little, and the ossification was not synchronous with the material degradation. In Group C, however, new bone was observed to form early and massively, and the os- sification was almost synchronous with the material degradation. In Groups A, B and C, the percentage of bone in the images of postoperative slices was (41.7?16.6)%, (31. 2?12.2)% and (71.7?21.0)% respectively. The bone percentage in CPC with composite rhBMP-2 was significantly higher than that in the other two types of CPC (P＜0.01 ). Conclusion The injectable and degradable CPC with composite rhBMP-2 is more suitable for clinical use, because it can induce early new bone formation and synchronous biodegradation.