Role Of Extracorporeal Shock Wave In The Treatment Of Delayed Union And Nonunion Of Bone Fractures:Animal Experiment And Clinical Observations

Part Ⅰ:Effect of extracorporeal shock wave on the bone fracture union process of ratsPurpose:To investigate the effects of extracorporeal shock wave on the bone frature union process of rats and explore the underlying mechanisms.Methods:Male rats were used for frature model, and they were divided into experimental group and control group. The former were treated with extracorporeal shock wave, and they were killed after treatment for1,2,3,4,8weeks respectively. Histology and biomechanics were used to analyze the bone samples.Results:After treatment for2,3,4weeks, the bone callus connection score, histological score and biomechanical results were significantly higher than control group (P<0.05).Conclusion:Extracorporeal shock wave could promote bone fracture union and it has promising future in treating nonunions in addition to surgery method. Part Ⅱ:Effect of extracorporeal shock wave on the VEGF expression during bone fracture union process of ratsPurpose:To study the effects of extracorporeal shock wave on the VEGF expression during bone fracture union process of rats.Methods:Male rats were used for frature model, and they were divided into experimental group and control group. The former were treated with extracorporeal shock wave, and femurs were extracted after treatment for1,2,3,4weeks respectively. RT-PCR and Western blot were used to investigate the mRNA and protein expression of VEGF in bone callus. Immunohistochemistry were used to study the expression of VEGF and VEGFR2in bone callus.Results:VEGF mRNA and protein are both expressed in frature union process of both groups. Furthermore, the expression are stronger in experimental group than control group, which is more obvious after treatment for2and3weeks. Immunohistochemistry resuls showed that VEGF and VEGFR2expression are more significant in bone callus of experimental group.Conclusion:Extracorporeal shock wave upregulated VEGF expression, thus promoting angiogenesis. This might be the reason why extracorporeal shock wave could promote bone frature union, and2and3weeks after treatment are the key time points. Part III:Clinical observations of application of extracorporeal shock wave in27cases of delayed union and nonunionPurpose:To study the therapeutic effects of extracorporeal shock wave on delayed union and nonunion.Methods:27cases of delayed union and nonunion patients were treated with extracorporeal shock wave equipment (EMS DolorClast), the energy was between3.0-4.0bar(0.35～0.55mJ/m m2), the frequency was6Hz,4000times each time. All patients were treated for4times and the interval was7d.Results:After treatment for12to18months,19of27cases had obvious bone callus and got frature union eventually. There was no effect on another7cases. The average time for union was18.4weeks.74.1%was effective after12months. There were no vascular and nerve injury, and no breakage of internal fixations after treatment, only acompannied by swelling of local skin.Conclusion:Extracorporeal shock wave was a simple, microinvasive, safety and economic method for frature nonunion or delayed union.