掌侧逆行固定治疗腕舟骨腰部骨折三维有限元分析

摘要

Objective To establish the three-dimensional finite element model of scaphoid waist fracture retrograde and antegrade screws fixation, analyze and compare the biomechanical stability of scaphoid waist fracture post retrograde and antegrade screws fixation, in order to provide biomechanical basis for retrograde screws fixation. Methods We obtained the Structural information of the distal ulna and distal radius and the carpal and the proximal of Metacarpal bone through the CT scan, and established the scaphoid waist fractures model by using the three-dimensional finite element software. Then, as a reference to the clinical surgical procedures, we established the different angles retrograde screw fixation model and the three-dimensional finite element model of post antegrade fixation while screws were placed along the axis line of Scaphoid. We simulated the forces of scaphoid waist fractures post screw fixation, and analyzed the horizontal displacement of fracture and the maximum stress that screws suffered of retrograde fixation while Screw fixation in different locations and compared with antegrade fixation. Results In all retrograde screws fixation models, the stress that screws suffered and the horizontal displacement of fracture were both minimum while screws were placed along the axis line of Scaphoid. Among all the models, the stress that screws suffered and the horizontal displacement of fracture were both minimum in all antegrade screws fixation models, and was very closed to the retrograde screws fixation models while screws were placed along the axis line of Scaphoid. Conclusion In all antegrade fixation model ,the screw in the axis of the scaphoid is the most stable model, and biomechanical stability of retrograde and antegrade screws fixation had no significant difference while screws are placed along the axis line of Scaphoid.%目的 建立腕舟骨腰部骨折掌侧入路螺钉逆行固定与顺行固定的三维有限元模型,分析对比逆行固定与顺行固定术后的生物力学稳定性,为逆行固定提供生物力学依据.方法 通过CT扫描获取尺桡骨远端、各腕骨与掌骨近端的空间结构信息,利用三维有限元软件建立腕舟骨腰部骨折模型.接着以临床手术操作为参照,建立不同角度螺钉逆行固定模型以及将螺钉置于腕舟骨轴线的顺行固定术后的三维有限元模型.模拟腕舟骨腰部骨折螺钉内固定术后的受力情况,比较分析逆行固定不同螺钉内固定位置骨折端水平位移和螺钉所受最大应力大小,并与顺行固定模型对比.结果 在所有逆行固定模型中,螺钉在腕舟骨轴线上时螺钉所受应力最小、骨折端水平移位最小.在所有模型之中,顺行固定模型螺钉所受最大应力最小、骨折端水平移位最小,且与逆行固定螺钉在腕舟骨轴线时的模型非常接近.结论 逆行固定时将螺钉置于舟骨轴线时模型最稳定,而当螺钉置于舟骨轴线上时,逆行固定与顺行固定生物力学稳定性未见明细差异.