TiNbZrTa医用钛合金接骨器对兔骨折端骨愈合影响的实验研究

目的探讨钛铌锆钽(TiNbZrTa)医用钛合金接骨器对兔骨折端骨愈合的影响。方法清洁级日本大耳白兔20只分为TiNbZrTa组(Ti组)、普通钢板组(钢板组)。于骨折建模后分别予TiNbZrTa接骨器及普通钢板固定骨折端,随机抽取10只兔于骨折前后、接骨器手术后以及术后的第7、14、28、56、84天测定骨折端骨生物电位。结果与骨折建模前比较,骨折后两组骨生物电位均为负值,安放内固定后电位进一步降低,其中钢板组较Ti组降低更明显(P<0.05)。术后2周钢板组骨折端负性电位开始回升,术后8周接近正常生物电位;而Ti组术后电位虽然波动较小,但始终保持负电位,术后12周在原骨折部仍能测到较低的负电位(P<0.05)。术后84 d镜检,Ti组与钢板组均可见原始骨痂中的新生骨小梁,骨折端的坏死骨被清除,新生骨形成,完成爬行替代过程,Ti组骨折部已完全移行为板层骨,哈佛管排列整齐,血管化明显。钢板组主要由编织骨组成,哈佛管排列较Ti组紊乱。结论钛铌锆钽(TiNbZrTa)钛合金较传统钢板材料具有一定的优势,可作为新型生物医用金属植入材料的一种新的选择。

Experimental research of TiNbZrTa alloys in promotion of humeral fracture healing in rabbits

Objective To explore the effect of bone healing of TiNbZrTa medical titanium alloy after rabbit humeral shaft. Methods Twenty clean level Japanese big ear rabbits were divided into TiNbZrTa plate group and steel plate group. After fracture modeling, TiNbZrTa plate and ordinary steel plate were used to fix the fracture ends respectively. Ten rabbits were randomly pick out at the time point of pre-and post-fracture, post-operation of fixation and the post-operative 7th, 14th, 28th, 56th and 84th day for the de- termination of bone biological potentials. Results Relative to that of pre-fracture modeling, the bone biological potentials of post- fracture were negative in the two groups. Potentials further reduced after internal fixation, which was more obvious in the steel plate group than in the TiNbZrTa plate group （P 〈 0.05 ）. The potential of the steel plate group began to rebound after 2 weeks and was close to normal biological potential at 8 weeks. The postoperative potential in the TiNbZrTa plate group was less volatile and kept negative, and lower negative potential could be detected in the original fracture part at 12 weeks postoperatively （P 〈 0.05 ）. On the 84th day postoperatively, new bone trabeculae in the original callus were visible in both the two groups. The necrotic bone was cleared and new bone formed with the completeness of creeping substitution. The once fractured bone in the TiNbZrTa plate group migrated for lamellar bone completely, with neat haversian canal and obvious vascularization. Bone in the steel plate group was mainly composed of woven bone and haversian canal more disordered than that in the TiNbZrTa plate. Conclusion As a new bio- medical metallic implant material, titanium alloy （TiNbZrTa） has advantage over traditional steel material in promotion of fracture healing.