【作者】 杨立；

【导师】 罗教明；

【作者基本信息】 四川大学 ， 生物医学工程， 2005， 硕士

【摘要】 动力髋螺钉(DHS)、动力髁螺钉(DCS)和GAMMA钉是目前临床固定股骨转子间骨折应用最多的三种类型,但至今没有一种固定钉能普遍适用于股骨转子间骨折的各种情况,而且上述三类钉的使用和疗效,不同的学者持不同的看法并存在争议。 对于以上三种固定钉的力学特性的研究目前大多数依靠实验数据,但这些数据一般是在离体情况下测量的,而且应用于骨植入体的力学测量存在样本的选择、实验手段的不同等局限性,因此实验数据与真实情况有较大差异。本文采用有限元(FEA)方法,基于螺旋CT数据,应用计算机断层处理技术,建立了股骨的精确CAD和FE模型,模拟计算得到了动力髋螺钉(DHS)、动力髁螺钉(DCS)和GAMMA钉应用于股骨间转子不稳定骨折固定的生物力学数据,通过对计算结果的比较分析,得出以下结论: 1)在不稳定股骨转子间骨折的治疗中,Gamma钉适用于所有骨折类型,但是其远端的应力集中是其固有缺点,需要在设计上进行改进。 2)在31-A2型不稳定股骨转子间骨折的治疗中,若股骨距粉碎不严重,缺损不多或者无缺损,手术中能够立即重建股骨距区的稳定性,宜选择DHS固定,这时如果采用更坚强的内固定Gamma钉,则对股骨矩产生了应力屏蔽的作用;若粉碎严重且术后不能够立即重建股骨距区的稳定性,则宜选择更坚强的内固定Gamma钉固定。DCS不适用于31-A2型骨折的治疗。 3)在31-A3型不稳定股骨转子间反向型骨折的治疗中,同样的若股骨距粉碎不严重,缺损不多或者无缺损,手术中能够立即重建股骨距区的稳定性,宜选择DCS固定,这时如果采用更坚强的内固定Gamma钉,则对股骨矩产生了应力屏蔽的作用;若粉碎严重且术后不能够立即重建股骨距区的稳定性,则宜选择更坚强的内固定Gamma钉固定。DHS不适用于31-A3型骨折的治疗。不是首选内固定物。更多还原

【Abstract】 Intertrochanteric fracture of femur is a serious and common injury that would lead to permanent disability, pneumonia, pulmonary embolism, and even death. The ongoing debate on the surgical treatment of trochanteric hip fracture, particularly unstable fracture, has triggered continuous changes in the design of well-established implants and prompted the development of new ones. The goal of this paper is to use finite element simulation to compare the biomechanical behaviour of three implants most often used in the hospital in China: DHS,DCS and the standard Gamma-nail. The focus was on the displacement of the fracture focus and the stress distributions along the interface of the femur and the implant. Computed tomographic (CT) scan-based finite element (FE) modeling technique is a tool that can predict proximal femoral fracture load in vitro. CT scans of the left proximal femur of human were obtained, from which three-dimensional FE models with nonlinear mechanical properties were constructed. Maximum femoral head reaction force was applied as the FE-predicted fracture load.The effects of the different types of fracture were investigated. The results showed that, according to biomechanic principle in the treatment of peritrochanteric fracture, fracture treated with Gamma-nail is satisfactory. It is found that Gamma-nail could produce higher contact stress between the tip of the nail and the endosteum. Furthermore, this contact stress is reducedwhen the distal region of the nail is made more flexible either by incorporating longitudinal slots or by assuming the material of a lower modulus of elasticity. On the unstable conditions,the Gamma-nail is stiffer than the DHS and DCS .In the A2 fracture,the DHS can be regarded as realistic surgical model to treat the unstable intertrachanteric fracture of the femur,not the DCS.But in the A3 fracture,the DCS can be regarded as satisfiable surgical model to treat the intertrachanteric fracture of the femur,DHS is not suitable in this type frctures. The key to successful treatment is accurate implantation of the internal fixation device and appropriate perioperative managanent.更多还原