Abstract:Objective Through the three-dimensional finite element method,the advantages and disadvantages of the “F” fixation method and the traditional fixation method were compared in the treatment of femoral neck fracture,in order to provide the most optimal one for clinical application.Methods Using the reverse modeling technology,the bone of normal adult volunteers proximal femur was scanned by CT.Mimics10.0 and Geomagic 2012 software were used to reconstruct the 3D structure of the femur,the femoral neck fracture model (Pauwels angle=70 degrees) was simulated in the Cero3.0,And then the nails were implanted according to the traditional fixation method (the control group) and the “F” fixation method (the experimental group).In Abaqus 6.14,two working conditions,single foot standing and double foot standing,were calculated.Results a) In the control group,the stress was concentrated on the upper end of bolt,the bottom of the two lower screws,and the calcar femorale.In the experimental group,the stress mainly concentrated in the screw,and distributed evenly along the screw to the nail tail and surrounding bone.The stress distribution at the fracture end of the fracture,especially at the calcar femorale.b)Compared with the control group,the experimental group had significantly reduced stress distance (P<0.01) at the fracture distance of the calcar femorale,reduced total displacement of the femoral head (P<0.05) and the relative displacement of the fracture end (P<0.05).Conclusion The shape of “F” technology can not only eliminate the torsional stress and shear stress at the fracture end while maintaining axial compressive stress.The strong oblique nail implantation can form new core pillar in the cantilever structure,thereby effectively reduce the shear stress of fracture that provides good mechanical environment for fracture healing.
[1]Slobogean GP,Sprague SA,Scott T,et al.Complications following young femoral neck fractures[J].Injury 2015,46(3):484-491.
[2]Weil YA,Khoury A,Zuaiter I,et al.Femoral neck shortening and varus collapse after navigated fixation of intracapsular femoral neck fractures.[J].J Orthop Trauma,2012,26(1):19-23.
[3]Filipov O.Biplane double-supported screw fixation(F-technique):a method of screw fixation at osteoporotic fractures of the femoral neck[J].Eur J Orthop Surg Traumatol,2011,21(7):539-543.
[4]张浩,史雪峰,杨春宝,等.3枚与4枚螺钉置入治疗Pauwels Ⅲ型股骨颈骨折的有限元分析[J].中国组织工程研究,2016,20(26):3897-3902.
[5]杨成伟,李全,孙伟,等.内收型股骨颈骨折多根空心螺钉固定的三维有限元分析[J].中国矫形外科杂志,2009,17(14):1077-1080.
[6]赵庭波,吉璐宏,唐欢.正三角和倒三角排列治疗中青年股骨颈骨折疗效比较[J].实用骨科杂志,2016,22(4):372-375.
[7]Oden ZM,Selvitelli DM,Bouxsein ML.Effect of local density changes on the failure load of the proximal femur[J].J Orthop Res,1999,17(5):661-667.
[8]夏希,刘智.老年股骨颈骨折空心螺钉固定术后颈短缩的测量及其对髋关节功能的影响[J].中华创伤骨科杂志,2014,16(8):651-655.
[9]Filipov O,Gueorguiev B.Unique stability of femoral neck fractures treated with the novel biplane double-supported screw fixation method:A biomechanical cadaver study[J].Injury,2015,46(2):218-226.