体外冲击波对兔长骨牵伸骨痂形成的早期作用

Early effect of extracorporeal shockwave treatment on distraction osteogenesis of long bone in rabbits

目的观察体外冲击波对兔长骨牵伸骨痂形成的早期作用,探讨其作用机制。方法30只成年新西兰大白兔胫骨中段截断,5d后开始延长,每天延长1mm,10d后停止延长,待骨痂形成10d;随机分成实验组和对照组,实验组于牵伸骨痂中心区进行体外冲击波(ESW)处理,冲击波能量密度0.54mJ/mm2,脉冲1000次;对照组不予任何处理。两组于截骨后45、60、75d取材,采用X线片、骨密度检测对牵伸骨痂形成进行观察,并行统计学分析,组织学观察比较。结果术后45d和60d,X线片及骨密度检测显示实验组牵伸骨痂形成量及骨密度值明显高于对照组(P<0.05),75d两组比较差异无显著意义;组织学观察发现45d实验组成熟软骨和类骨组织形成量均较对照组多,实验组新生骨痂内毛细血管数量较多,60d实验组可见大量新生骨组织,有丰富的骨髓腔和原始骨髓,对照组以类骨组织为主,原始骨髓少,75d两组间组织学形态趋于一致。结论在兔胫骨牵伸骨形成过程中,ESW可加速骨痂的早期形成、矿化和改建。

Objective To investigate the early effect of extracorporeal shockwave（ESW） treatment on distraction osteogenesis of rabbit tibias and its mechanism. Methods 30 adult New Zealand white rabbits were used. After osteotomy of left tibias, improved Orthofix M-100 bone fixator was applied. After 5 days, bone lengthening of 1 em was obtained over 10 days. Randomly the animals were divided into ESW and control groups. No ESW treatment was given to the control group. The shock wave was set at 0. 54 mJ/mm^2 and 1000 shots each time were applied to the central areas in the ESW group. Then the animals were divided into 3 sub-groups, and were killed respectively at 45, 60 and 75 days after osteotomy. During the process, X-ray, bone mineral density （BMD） and histological examinations were conducted for every animal. Results By X-ray and BMD measurements, we found significantly more bone mass increased in the ESW group than in the control group at 45, 60 days after operation （ P 〈 0.05）, but on the 75th day, there was no significant difference. Histological observations revealed that more mature cartilage, osteoblast-like tissue and capillaries in the cartilaginous callus were found in the ESW group than in the control group on 45th day. On 60th day, there were a large amount of new osteoblast tissue, marrow cavity and primary marrow in the ESW group, but in the control group, there was not much primary marrow. On 75th day there was no significant difference between the 2 groups. Conclusions During the process of tibial lengthening in rabbits, ESW can promote early osteogenesis, ossification and restructure of bony callus.