摘要
背景：国外聚左旋乳酸微型接骨板和螺钉的价格昂贵，限制了其在国内的广泛应用。目的：观察国产聚左旋乳酸微型接骨板在家犬体内的力学衰减过程及其降解特性。设计、时间及地点：随机对照动物体内实验，于2005—01/2006—12在吉林大学第一医院整形外科实验室完成。材料：聚左旋乳酸接骨板和螺钉由中国科学院长春应用化学研究所研制，初始分子质量约7．5×10^4，杨氏模量3．3～3．6GPa，强度48～55MPa。方法：在12只成年杂种犬下颌骨建立双侧骨折模型，采用聚左旋乳酸接骨板螺钉固定系统行骨折内固定。然后按取材时间随机分为术后1，3，6，12个月4个时间点，每个时间点3只。主要观察指标：观察各时间点接骨板大体降解情况，测试接骨板三点弯曲强度，检测接骨板黏均分子质量并计算其降解率。结果：12只犬均进入结果分析。降解过程中接骨板最大抗弯强度随时间的延长呈逐步下降的趋势。术后6个月，衰减率已达到初始强度的82.31％，各个时间点间均存在显著差异（P〈0．05）。随着降解时间的逐渐延长，接骨板黏均分子质量呈现下降趋势，至术后12个月，分子质量降解率已达91．80％，各时间点间均存在显著差异（P〈0．05）。将按骨板最大抗弯强度衰减率与接骨板黏均分子质量降解率间进行双变量相关性分析，显示两者呈正相关性（r=0．876，P〈0．05）。结论：随时间的变化聚左旋乳酸微型接骨板逐渐降解，其力学强度逐渐减弱，分子质量逐渐降低，其降解过程与下颌骨骨折的愈合过程基本相符合。
BACKGROUND： Poly（L/lactide） （PLLA） miniplate and screw cost too high at abroad to be applied domestically. OBJECTIVE： To investigate the mechanical attenuation and degradation characteristics of PLLA miniplate in dogs. DESIGN, TIME AND SETTING： The experiment, a randomized control trial in animals, was performed at the Department of Plastic Surgery, the First Hospital of Jilin University from January 2005 to December 2006. MATERIALS： PLLA miniplate and screw were produced in Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. Initial molecular mass was 7.5×10^4, Young modulus was 3.3-3.6 GPa and strength was 48-55 MPa. METHODS： Totally 12 adult hybrid dogs were used to create the models of mandibular body fracture on both sides, and fixed with PLLA plates and screws. The dogs were sacrificed separately at 1, 3, 6, 12 months after operation, three animals at each time. MAIN OUTCOME MEASURES： The macroscopic observation was performed to evaluate the degradation of bone plate. The viscosity average molecular weight and three-point bending tests of PLLA plates were investigated. The degradation rate was also measured. RESULTS： All 12 animals were involved in the result analysis. The maximal bending strength of the miniplates decreased with time going on during degradation. At 6 months, the rate of attenuation was 82.31% of the initial strength, and there were significant statistical differences among different time points （P 〈 0.05）. The molecular weight of the miniplate decreased gradually and the degradation rate was 91.80% at 12 months, there were significant statistical differences among different time points （P 〈 0.05）. Double variables analysis was used to analyze the degradation rate of the molecular weight and the attenuation rate of the maximal bending strength, results showed that the two were positively correlated （r=0.876, P 〈 0.05）. CONCLUSION： The mechanical strength and the molecular weight of PLLA miniplates decrease gradually following the degradation of the miniplate in vivo, which is correspondent with the fracture healing process.
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2008年第36期7105-7109,共5页
Journal of Clinical Rehabilitative Tissue Engineering Research
基金
国家自然科学基金资助项目(30670563)
吉林省科委资助项目(20030423-01)~~
