桡骨骨髓腔形态观测和弹性蛇形髓内针的临床研究

The Study about Anatomical Measure of Chinese Radius Medullary Cavity and Clinical Observation of Snake-shaped Intramedullary Nail

目的 :通过对桡骨骨髓腔形态解剖学测量 ,为弹性蛇形髓内针 (Snake shapedIntramedullaryNailSIN)设计提供解剖学依据。并测试该针的生物力学性能及探讨其在桡骨骨折治疗中的临床应用。方法 :(1)将国人桡骨 3 0例 ,按2 0等份横断 ,观察髓腔形态 ,并测量纵径和横径 ;(2 )将 2 7根桡骨标本分为 3组 ,制成中段骨折模型 ,分别置入SIN ,三棱针及骨圆针 ,在WO -10实验机上进行扭转、轴向拉伸及弯曲试验。临床应用 2 0例。结果 :桡骨骨髓腔中间小 ,两端大 ,上端圆或椭圆 ,骨干和下端扁圆。其髓腔最窄处为桡骨中份 ,纵径平均 4.4mm ,横径 5 .9mm。SIN组的最大抗扭转、抗轴向拉伸及内外抗弯刚度均优于三棱针组及骨圆针组 (P <0 .0 5 )。所有病例均经随访 ,平均 14个月 ,骨折全部愈合。按前臂疗效评定标准 ,优良率为 90 %。结论 :(1)SIN设计合理 ,具有良好的生物力学性能 ,有较强的骨折固定作用和稳定性 ,尤其在抗旋转和抗拉性能方面。适用于治疗桡骨骨折。 (2 )该针具有操作简单 ,创伤小 ,并发症少 ,便于推广。

Objective: Anatomic study of the medullary cavlity of adult radial specimens.To provide anatomical basis of the design of the Snake shapped intramedullary nail(SIN).To test the biomechanical characteristics of SIN designed by the authors and studied the use of it in the treatment of radius shaft fractures Methods:①Thirty adult radius were used.Each of them were divided into 20 equal portions and transversally sawed into 20 cros s sections.The Shape and anteroposterior and transverse diameters of medullary cavity of each section were observed and measured.②Twenty seven specimens of radial were undergone total osteotomy at diaphysis and divided into three groups.One group was implanted with SIN.The second group was treated with triagular nail.Another group was theated with Kirschner's wire.Bending test.torsion and axial tensil test were performed on the WO 10 testing machine Twenty patients with radius fracture were stabilized with SIN.Results:The medullary cavity of the radius is small in the middle portion and that cavity in the upper and lower ends are comparatively larger.The cross section in the upper end is round or oval.while that of shaft and lower end is flat.The cross section of lower radius medullarg cavity was oval and the smallest area of them located in the middle portion of the radius and it anteroposterior and transverse diameters were 4.4mm and 5.9mm respectively.All results suggested that the torsion rigidity.bending and axial tensile stiffness of SIN are better than triangular nail and Kirschner's wire group( P <0.05).After average 14 months follow up all of the fractures had union and the overall excellent rate was 90%.Conclusion:①SIN is well designed.it's fine biomechanical characteristics in fixation for radius fractures especially in anti torsion and axial tension.It can be adopted in the treatment of radius shaft fractures.②It is easy to be used.It has advantages of manipulated easier and fixed stable.