支撑-牵张效应对股骨转子间骨折内固定稳定的影响

Buttress and stretch effect of internal fixation for femoral intertrochanteric fractures

股骨转子间骨折是常见的老年骨质疏松性骨折,手术内固定是首选的治疗方法,目的是利用内固定物分担髋关节传导的负荷。当前开展的研究大多围绕股骨近端的外侧壁、内侧壁、尖顶距及棘轮机制等学说,基于这些学说设计的单一头颈螺钉或双头颈螺钉的髓外、髓内设计均无法完全避免股骨头穿透的发生。根据股骨近端骨小梁的分布及骨折前后的生物力学变化特点提出的杠杆平衡重建理论可阐明内固定术后头颈螺钉所受应力的动态变化趋势,在该理论基础上进一步提出了影响股骨转子间骨折内固定稳定的支撑-牵张效应,阐明了骨折术后内固定螺钉穿透股骨头的发生原因和机制。根据支撑-牵张效应理念,建议采用股骨近端仿生髓内钉治疗股骨转子间骨折,以预防螺钉穿透股骨头,为未来股骨转子间骨折的内固定治疗提供新的思路。

Intertrochanteric fractures of femur are common osteoporotic fractures in the elderly,and internal fixation is the preferred treatment method.The purpose is to use internal fixators to share the load conducted by the hip joint.Most of the current researches focus on theories of the lateral wall,medial wall,apex distance,and ratchet mechanism etc of the proximal femur.However,neither the extramedullary nor the intramedullary designs of single head-neck screws or double head-neck screws based on these theories can completely avoid the occurrence of femoral head penetration.According to the distribution of trabecular bone in proximal femur and the biomechanical change characteristics before and after fracture,the lever-balance reconstruction theory was proposed,and the therapy clarified the dynamic changes of stress on head-neck screws after internal fixation.On the basis of this theory,the author further proposed the buttress and stretch effect that affected the stability of internal fixation of femoral intertrochanteric fractures,and clarified the causes and mechanisms of internal fixation screw penetration of femoral head after fracture operation.In view of this effect,it is recommended to use proximal femoral bionic nail(PFBN)for the treatment of femoral intertrochanteric fractures to prevent the screw from penetrating the femoral head,providing a new idea for the internal fixation of intertrochanteric fractures in the future.