改良中空加压螺钉复合可注射BMP缓释载体治疗犬股骨颈骨折的实验研究

Treatment of femoral neck fracture using modified cannulated screw with injectable BMP release system

[目的]建立犬股骨颈骨折的动物实验模型,观察改良中空加压螺钉-BMP缓释系统在股骨颈骨折治疗中的应用。[方法]选用健康成年杂种犬18只,均采用手术方法造成双侧股骨颈移位骨折模型,对照侧采用改良中空加压螺钉内固定、实验侧采用改良中空加压螺钉内固定复合可注射BMP缓释载体,实验动物分别在4、8、12周处死取材,通过X线片及大体组织病理学等方法观察股骨颈骨折愈合过程。[结果](1)X线检查4周时骨折线模糊,8周骨折已基本消失,12周时骨折完全愈合,头内骨小梁清晰,密度正常,均无坏死表现,分别请放射科2位医师单盲对比全部犬实验侧及对照侧骨折愈合情况均认为实验侧优于对照侧;(2)组织学观察也发现术后4、8、12周实验侧较对照侧股骨颈修复过程快。[结论]改良中空加压螺钉-BMP定向释放系统的设计思路是可行的,该系统既能完成骨折端加压,达到坚强的内固定,又能向骨折端输注缓释生长因子,有利于促进骨折早期愈合,为此法应用于临床提供了实验依据。

[Objective]To treat the femoral neck fracture using cannulated screw and BMP release system in animals,and to evaluate the possibility of treating femoral neck fracture and provide experimental basis for clinical application.[Method]Eighteen mongeral were used in this study.The model of bilateral femoral neck dislocation fracture was established.The control side was fixed using cannulated screw,and the experiment side was fixed with cannulated screw and injectable BMP release system.At 4,8,12 weeks,6 animals were sacrificed at one time point respectively.Results were obtained through histology,radiography,scintimetry and gross observation.[Result]The fracture line was vague at four weeks,and at eight weeks the fracture line almost disappeared.It was healed completely at twelve weeks.Radiological study showed that the healing of the fracture in experimental side was better than that of the control side.There was the same result of observation in histology.[Conclusion]The cannulated screw combined with BMP used in the experiment is effective and feasible.It may not only provide strong internal fixation but also infuse growth factor into site of fracture.It would accelerate the reconstructing of the vascular supply to the femoral head after the fracture and promote the restoration of bone.