骨折端加压螺钉结合锁定钢板固定老年股骨远段简单骨折的生物力学分析  

Biomechanical analysis of interfragmentary lag screw combined with locking plate fixation for simple distal segement femoral fractures in the elderly

作　　者：张俊[1] 厉国定[1] 王健[1] ZHANG Jun;LI Guo-ding;WANG Jian(Dept of Orthopaedics,Shanghai Pudong New Area People′s Hospital,Shanghai 201299,China)

机构地区：[1]上海市浦东新区人民医院骨科,上海201299

出　　处：《临床骨科杂志》2022年第6期894-899,共6页Journal of Clinical Orthopaedics

基　　金：上海市浦东新区卫健委学科带头人培养计划(编号:PWRd2020-15)。

摘　　要：目的比较单纯钉板系统(单纯法)与骨折端加压螺钉结合锁定钢板(联合法)固定老年股骨远段简单骨折的生物力学强度。方法建立AO/OTA-33 A1型老年股骨远段骨折模型,分别用102 mm工作长度单纯法(A组)和联合法(B组)、82 mm工作长度单纯法(C组)和联合法(D组)固定。施加700 N轴向和4 N·m扭转载荷,比较锁定钢板的应力分布及峰值、位移分布及峰值、骨折端剪切位移、骨折端轴向位移。结果(1)锁定钢板的应力分布及峰值情况:使用骨折端加压螺钉后,应力峰值从骨折线区域的股骨干侧方钢板转移到骨折线区域的拉力螺钉,而锁定钢板上的应力峰值明显降低。(2)锁定钢板的位移分布及峰值情况:使用骨折端加压螺钉后,锁定钢板上的位移峰值明显降低,联合法模型组的位移均小于单纯法模型组。(3)骨折端剪切位移情况:联合法模型组均小于单纯法模型组。上述3项指标,700 N轴向载荷下,82 mm工作长度模型下降幅度均更大;4 N·m扭转载荷下,102 mm工作长度模型下降幅度均更大。(4)骨折端轴向位移情况:扭转载荷下可忽略不计;轴向载荷下联合法模型组均小于单纯法模型组,82 mm工作长度模型下降幅度更大。结论对于老年股骨远段简单骨折,联合法固定能分担锁定钢板上的应力及使骨折断端更稳定,102 mm工作长度可提供更好的抗扭转稳定性,82 mm工作长度可提供更好的轴向稳定性。Objective To compare the biomechanical strength of simple screw-plate system(simple method)and interfragmentary lag screw combined with locking plate(combined method)for simple distal segement femoral fractures in the elderly.Methods The elderly femoral distal segement fracture model of AO/OTA-33 A1-type was established,and the model was fixed with the following four kinds of methods,including 102 mm working length simple method(group A),102 mm working length combined method(group B),82 mm working length simple method(group C),and 82 mm working length combined method(group D).The 700 N axial loads and 4 N·m torsional loads were applied to compare the stress distribution and its peak value,micromotion distribution and its peak value,interfragmentary micromotion(shear,axial)of the locking plate.Results(1)Stress distribution and peak value of the locking plate:with an interfragmentary lag screw,the stress peak was transferred from the lateral plate of femoral shaft in the fracture line zone to the lag screw in the fracture line zone,while the stress peak on the locking plate was significantly decreased.(2)Micromotion distribution and peak value of locking plate:with an interfragmentary lag screw of fracture end,the micromotion peak on the locking plate was significantly decreased,and the micromotion value of the combined method groups were smaller than those of the simple method groups.(3)Shear micromotion of fracture end:which of the combined method groups were smaller than those of the simple method groups.For above three indexes,under 700N axial load,the 82 mm working length model had greater decrease degree;and under the 4 N·m torsional load,the102 mm working length model had greater decrease degree.(4)Axial micromotion of fracture end:under torsional load,the micromotion were negligible;under the axial load,the axial micromotions of the combined method groups were smaller than those of the simple method groups,and the 82 mm working length model had greater decrease degree.Conclusions For simple distal segemen

关 键 词：股骨远段骨折 拉力螺钉 内固定 生物力学 老年人 

分 类 号：R683.42[医药卫生—骨科学] R687.32[医药卫生—外科学]