With the gradual aging of the nation, the incidence of intertrochanteric fractures in the elderly has gradually increased, accounting for about 1.4% of all fractures in the body, and according to Horowitz, the death rate of non-operative treatment of intertrochanteric fractures in the elderly is as high as 34.7%. The main cause of death is due to complications and worsening of coexisting diseases after the fracture is bedridden. In order to enable the elderly patients with osteoporosis to have early functional exercise and early landing, and to improve the quality of life and reduce bedridden complications, the current consensus is to adopt surgical treatment, and the mortality rate after surgery is 6%-20% (Miskchkowskyt reported), and the proximal femoral intramedullary nail-anti-spiral blade and surgical techniques have been developed for the characteristics of osteoporosis in the elderly. In response to the characteristics of osteoporosis in the elderly, Dr. Liu Shifeng carried out closed reduction PFNA internal fixation surgery for elderly patients with intertrochanteric femoral fractures. The advantages of this technique are: 1. Small incision, little destruction of surrounding tissues, less surgical bleeding, and PFNA is a minimally invasive fixation system that does not require stripping of soft tissues and periosteum at the fracture end, and makes full use of the splinting effect of soft tissues around the fracture to reset the broken bone fragments, which protects the biological environment of the fracture end and conforms to the principles of biological fixation and minimally invasive surgery, which facilitates fracture healing. The surgical operation is simple, the surgical exposure time is short, and only the lateral cortex needs to be opened during the operation without marrow expansion, which reduces the damage to the medullary vessels during marrow expansion, avoids the occurrence of intrinsic blood loss, and reduces the risk of the operation. 2, PFNA this new intramedullary fixation system is mainly developed for elderly patients with osteoporosis, which has distinctive features. (1) PFNA spiral blade has greater holding force, the spiral blade into the filling pressure around the bone, the blade can automatically lock, the blade makes the femoral head neck cross-section to form a quadrilateral bone tunnel, its wide blade contact surface closely contact the compacted bone, the formation of a solid anchor force between it and the femoral head neck to form a strong fixation, to avoid the locking nail loosening, withdrawal. (2) The cutting stress of the spiral blade on the femoral head is significantly reduced. Strauss et al. reported the results of biomechanical studies on the PFNA spiral blade, which required a stress of at least 1000 N to cause cutting on the femoral head. (3) PFNA has a strong sliding ability, and the powering can compress the fracture end while obtaining a better anti-rotation and support effect, and the short force arm and small bending moment of the PFNA system can bear most of the load passing through the proximal femur, especially the medial side, so that the compressive and tensile stresses acting on the fracture end are relatively reduced, and the compressive stresses in the femoral distance area are reduced to almost zero, and the force arm is shifted inward to reduce the tensile and compressive stresses at the nail bar joint (3) The main nail has a long length, and the nail has a long length. (4) The main nail has a long tip and groove design, which can facilitate intraoperative insertion and avoid local stress concentration, and the longer distance between the distal locking nail and the tip achieves elastic fixation and reduces the incidence of broken nails and re-fracture at the tip. PFNA is an effective fixation system for patients with osteoporosis, with the characteristics of small trauma, simple operation and reliable fixation, which enables the patient to be on the ground for early weight bearing and functional exercise after surgery, improving the patient’s quality of life and reducing complications. It is an effective fixation system for patients with osteoporosis.