摘要
目的比较双头与单头螺纹空心钉固定治疗PauwelsⅢ型股骨颈骨折的生物力学性能。方法采用Sawbone人工合成骨制作标准化的PauwellsⅢ型(70°)股骨颈骨折模型。标本分为两组(n=12):A组为单头螺纹空心螺钉固定组,B组为双头螺纹空心螺钉固定组。螺钉长90~95 mm,直径为7.3~7.5 mm。两组标本均采用"倒三角形"空心钉固定,固定后进行生物力学测试。比较两组股骨颈骨折模型空心钉固定后在7°(模拟双腿站立)和25°(模拟单腿站立)的轴向刚度、极限载荷;并进行扭转试验,比较两组标本旋转角度为1°、2°、3°、5°、7°时的扭矩。结果当倾斜角度为7°和25°时,B组模型的轴向刚度[(89±26)、(128±37)N/mm]均显著高于A组模型[(36±12)、(47±16)N/mm],极限荷载[(1154±368)N]也显著大于A组模型[(688±94)N],差异均有统计学意义(P<0.05)。两组标本的扭矩均随旋转角度增加而增大,但B组模型的扭矩[(3.26±0.96)、(4.16±1.23)、(4.64±1.13)、(5.59±1.26)、(6.53±1.47)N·m]较A组模型[(1.44±0.19)、(2.03±0.41)、(2.33±0.62)、(2.74±0.87)、(3.05±1.07)N·m]更大,差异均有统计学意义(P<0.05)。结论双头螺纹空心钉较单头螺纹空心钉具有更强的抗压和抗扭转能力,生物力学稳定性更好。
Objective To compare the biomechanical performance between the single-versus double-threaded cannulated screws in the treatment of femoral neck fractures of Pauwels typeⅢ.Methods Models of femoral neck fracture of Pauwels typeⅢ(70°)were made of the Sawbone synthetic composite femurs.All specimens were divided into 2 groups(n=12).Group A was fixated with single-threaded cannulated screws and group B with double-threaded cannulated screws,both in an inverted triangle configuration.The screws ranged from 90 to 95 mm in length and from 7.3 to 7.5 mm in diameter.All the specimens were subjected to axial stiffness and failure load tests with 7°valgus(simulating normal two-legged weight-bearing stance)and 25°valgus(simulating normal one-legged weight-bearing stance)and torsion test as well.The 2 groups were compared in the torques at axial stiffness angles of 1°,2°,3°,5°and 7°.Results Group B had significantly greater axial stiffness at 7°valgus and 25°valgus(89±26 N/mm and 128±37 N/mm)and failure load(1,154±368 N)than group A did(36±12 N/mm and 47±16 N/mm;688±94 N)(P<0.05).The torques increased with the increase in rotation angle in both groups.However,the torques in group B(3.26±0.96,4.16±1.23,4.64±1.13,5.59±1.26 and 6.53±1.47 N·m)were all significantly larger than in group A(1.44±0.19,2.03±0.41,2.33±0.62,2.74±0.87 and 3.05±1.07 N·m)(P<0.05).Conclusion Double-threaded cannulated screws may provide better biomechanical stability than single-threaded ones,due to their substantial improvement in anti-compression and anti-rotation performance.
作者
相庚
冯亚非
程建刚
高扬
胡晓帆
马田成
裴国献
孟国林
Xiang Geng;Feng Yafei;Cheng Jiangang;Gao Yang;Hu Xiaofan;Ma Tiancheng;Pei Guoxian;Meng Guolin(Department of Orthopaedics,Xijing Hospital,The Medical University of Air Forces,Xi’an 710032,China)
出处
《中华创伤骨科杂志》
CAS
CSCD
北大核心
2019年第12期1064-1068,共5页
Chinese Journal of Orthopaedic Trauma
基金
国家自然科学基金(81871799)。
