内植静磁柱联合脉冲电磁场对骨组织修复作用的Micro-CT研究

摘要

Objective:To evaluate effect of pulsed electromagnetic fields combined with a static magnetic intramedullary implant on bone defects repair using Micro-CT technique.Methods:A total of 24 healthy New Zealand rabbits were selected and randomly divided into the combined magnetic fields group,pulsed electromagnetic fields (PEMFs) group and the control group.The ombined magneticfields group:a static magnetic intramedullary implant was implanted in the right side of the rabbit femoral shaft distal.And combined with pulsed electromagnetic fields (1 h/d);The PEMFs group and thecontrol group implanted a non magnetic titanium alloy rod in the same position respective.Meanwhile,the PEMFs group also combined with pulsed electromagnetic fields (1h/d).At 5 weeks after operation,Micro-CT was used to analyze the distal femur samples,and the 3D models of morphological structure were reconstructed by Mimics software.Results:Quantitative analysis of Micro-CT in bone defect region:compared with the control group,the combined magnetic group were significantly increased in BV/TV and Tb.N(P＜0.05),while decreased in Tb.Sp(P＜0.01).Compared with the PEMFs group,the combined magnetic group were increased in Tb.N (P＜0.05) and decreased in Tb.Sp (P＜0.01).By scanning and reconstruction image,bone mass increased and the cortical area has been repaired completely of the combined magnetic fields group.The trabecular bone has a continuous and compact microstructure.Conclusions:The combination of pulsed electromagnetic fields with the static magnetic intramedullary implants can obtain better bone formation and improve the microstructure in the early stage.%目的:以永磁体构建静磁柱体内植入物,应用Micro-CT技术,探索研究内植静磁柱联合脉冲电磁场对骨组织的修复作用.方法:选取新西兰兔24只建立右侧股骨髁骨缺损模型,并随机分为联合磁场组,脉冲电磁场组和对照组.联合磁场组自兔右侧股骨干远端向髓内植入静磁柱,并联合施加体外脉冲电磁场(1 h/d);脉冲电磁场组及对照组均将无磁性钛合金棒植入右侧股骨干髓腔,同时,脉冲电磁场组于体外加载脉冲电磁场(1 h/d).术后5周处死取材,应用Micro-CT对股骨远端样本进行扫描检测,并对骨缺损区域显微结构进行三维重建分析.结果:与非磁场组相比,联合磁场组骨缺损区域骨小梁相对体积及数目明显增加(P均＜0.05),骨小梁分离度下降(P＜0.01).与传统脉冲电磁场组相比,联合磁场组骨小梁数目增加(P＜0.05),骨小梁分离度下降(P＜0.01).扫描及重建图像可见,联合磁场组骨缺损区域骨量增多,外侧皮质区愈合完整,骨小梁结构连续致密,具有更好的骨显微结构.结论:内植静磁柱与脉冲电磁场的联合磁场干预方式能够在早期获得更好的成骨修复能力,为磁场治疗相关骨病的临床及基础研究提供了新的方向.