髋关节置换假体周围骨折钉棒内固定装置设计、生物力学分析与应用

Design,biomechanical analysis and application of nail-rod internal fixation device for periprosthetic fracture of hip joint replacement

目的针对髋关节假体周围骨折固定难、固定不牢靠的问题,设计了一种新型钉棒内固定装置,并对钉棒内固定装置设计、生物力学情况及临床效果进行分析。方法基于真实人体髋关节及股骨全长CT扫描数据,设计出髋关节置换假体周围骨折钉棒内固定装置,利用Mimics、UG8.0、Abaqus等软件,构建钉棒内固定装置的三维有限元模型并验证了模型的有效性。并将其用于1例Vancouver C型高龄女性患者的手术治疗中。结果此内固定装置经过三维有限元分析,骨骼受力较小,对骨折固定较稳定;此装置用于一例80岁高龄患者,术后2个月有明显骨痂生长,术后4个月骨折临床愈合,患者弃拐行走,术后效果良好。结论①新型内固定装置手术创伤较小,符合微创治疗理念,有利于骨愈合和骨生长,对患者的康复有很重要的作用。②新型内固定装置结构设计上采用股骨远端固定块和U型环抱装置以及连接块组合式结构,不仅具有结构简单、手术操作方便和减小创伤的特性,而且螺钉的置入位置和方向使得假体的稳定性增强,减小骨骼受力,极大地避免了假体周围再骨折的可能性。

Objective To solve the problems of difficult and unstable fixation of fractures around the hip prosthesis,a new type of screw rod internal fixation device was designed,and the design,biomechanical situation and clinical effect of the screw rod internal fixation device were analyzed.Methods Based on real human hip joint and full-length femoral CT scan data,the screw and rod internal fixation device around the prosthesis of hip replacement was designed.The three-dimensional finite element model of the screw and rod internal fixation device was constructed using Mimics,Geomagic,Abaqus and other software,and the validity of the model was verified.It was used in the surgical treatment of a Vancouver elderly female patient with type C.Results Three-dimensional finite element analysis showed that the bone had less stress and the fixation of fracture was more stable.This device was applied to an 80-year-old patient who showed obvious callus growth two months after the operation.The fracture was clinically healed four months after the operation.The patient abandoned the abduct and walked with good postoperative results.Conclusion①The new internal fixation device has less surgical trauma,conforms to the concept of minimally invasive treatment,is beneficial to bone healing and bone growth,and plays a very important role in the rehabilitation of patients.②A new internal fixation device,in the light of the distal femur fixed block structure design and U around devices and connection piece of modular structure,not only has the characteristics of simple structure,convenient operation and less trauma,but also the placement position and direction of the screw can enhance the stability of the prosthesis,reduce the stress on the bone,and greatly avoid the possibility of re-fracture around the prosthesis.