脑源性神经营养因子在大鼠胫骨骨折愈合中的作用

背景近期很多研究表明,神经系统的营养和支配对于骨发育和骨折愈合修复过程具有的作用.目的探讨脑源性神经营养因子对骨折愈合及其生物力学性能的影响.设计以实验动物为研究对象的随机对照实验.单位一所军医大学医院的创伤骨科和血液科.材料SD大鼠胫骨横行骨折髓内针内固定模型共16只,随机分到实验组和对照组各8只.干预术后实验组每隔1 d皮下注射脑源性神经营养因子(BDNF),对照组注射生理盐水,然后分别在第2,3,4,5周取动物胫骨进行结果观察.主要观察指标两组骨折愈合情况大体比较、生物力学测试和电镜观察.结果大体观察可见术后2周两组骨折均为结缔组织连接,可见明显的活动;3周时实验组已呈编织骨性愈合,而对照组仍有较明显的骨折端活动;4周两组均呈骨性愈合,但实验组的骨痂较小,成角畸形较小;5周时实验组骨折线已消失,骨折塑形好,对照组骨折端仍呈较大骨痂.大体测量骨折矢状面成角,在第3,4,5周实验组分别为(25.00±1.82)°,(24.75±2.50)°,(23.25±3.77)°,对照组分别为(32.00±2.45)°,(33.00±5.72)°,(29.25±2.22)°(P＜0.05).生物力学测试中,各个阶段实验组抗折应力均优于对照组(P＜0 05).结论早期、不间断的应用BDNF对骨折愈合修复过程中的各阶段均可能有促进作用.

Effects of brain-derived neurotrophic factor on healing of tibial fracture of rats

BACKGROUND: Recently, there are some researches show that the nutrition and control of nervous system play an important role in the growth of bone and healing of bone fracture.OBJECTIVE: To probe into the effects of brain-derived neurothophic factor on bone fracture healing and its biomechanic features.DESIGN: Randomized controlled study of experiment animals.SETTING: Traumatic orthopaedic and hematology department of a military medical university.MATERIALS: There were 16 SD rats with transverse fracture of shin,which were set up as intramedullary nail internal fixation. They were randomly divided into experiment group and control group with each of 8 mice.INTERVENTIONS: Rats in the experiment group were taken subcutaneous injection of brain derived neurotrophic factor(BDNF) every other day while control group was injected of saline. The shin of mice was collected to observe in the 2nd, 3rd, 4th and 5th weeks.MAIN OUTCOME MEASURES: Gross comparison of fracture healing of each group, biomechanical test and electro microscopic observation.RESULTS: It can be seen by gross observation 2 weeks after operation that the fracture area was linked by connective tissue in both groups and there was obvious movement. In the 3rd week, woven like bone healing could be seen in the experiment group whereas there was obvious fracture end movement in the control group. In the 4th week, bone healing could be seen in both groups, but the bone callus in the experiment group was much smaller with mild angled malformation. In the 5th week, the fracture line in the experiment group already disappeared and the molding of bone fracture was good while there was bigger bone callus in fracture end of the control group. The angle formed by sagittal planes of fracture in the 3rd, 4th and 5th week was(25.00 ± 1.82)°, (24.75 ± 2.50)°, (23.25 ± 3.77)° respectively in the experiment group and(32.00 ±2.45)°, (33.00 ±5.72)°, (29.25± 2.22)° respectively in the control group( P ＜ 0. 05) . The anti-fracture stress in each stage of the experiment group was better than that of the control group( P ＜ 0.05).CONCLUSION: Applying BDNF early and incessantly can stimulate all the stages of bone fracture healing.