Femoral neck fracture is a common and frequent clinical disease. With the aging of the population and the increasing severity of osteoporosis, the incidence of femoral neck fracture in the elderly is increasing year by year. In addition to artificial joint replacement, clinical treatment includes traction external fixation and various internal fixation methods. The key to treatment is firstly to reduce mortality and secondly to reduce femoral head necrosis. Long-term ambulatory traction has been recognized as a negative treatment method. It has poor efficacy with many complications and high mortality. Unless there are contraindications to surgery, surgical treatment should be aggressive. In primary hospitals, due to economic conditions or perceptions, a large proportion of patients are still treated with internal fixation. For internal fixation, there are Searle’s pin, scalene nail, double-headed pressurized threaded nail, and AO hollow nail. Our hospital has been using AO hollow nails for femoral neck fractures since 1998, and has achieved good results. Since February 2001, percutaneous hollow nailing has been used to treat femoral neck fractures, and this method has more advantages compared with the previous incisional internal fixation method. It is reported as follows. 1, Data and methods 1.1 Clinical data There were 56 cases in this percutaneous internal fixation group. Among them, 31 cases were male and 25 cases were female. The age ranged from 41 to 75 years. There were 32 cases on the left side and 24 cases on the right side. According to Garden’s typing: 10 cases of type 1, 38 cases of type 2, and 8 cases of type 3. Causes of injury: 42 cases of falls on flat ground, 11 cases of motor vehicle collision, and 3 cases of non-motor vehicle collision. Most of them had medical complications: 51 cases of myocardial ischemia, 40 cases of slow-branching emphysema, 2 cases of renal insufficiency, 48 cases of hypertension stage 3, and 5 cases of diabetes mellitus. 1.2 Surgical method Preoperative tibial tuberosity bone traction treatment was routinely performed to improve the preoperative preparation, especially for older patients with more concurrent evidence, preoperative routine supportive treatment, internal medicine consultation to deal with the cardiopulmonary situation, and then surgical treatment after stabilization-. The patient was repositioned on a supine orthopaedic traction bed, and the hip joint was kept in traction at 10° of abduction and 20° of internal rotation. During the repositioning process, the fracture was basically repositioned in the frontal and lateral views by C-arm X-ray machine, and the affected lower limb was fixed in the abducted and internally rotated position on the orthopedic traction bed. After routine disinfection and spreading of the towel, three Kirschner pins were inserted percutaneously under fluoroscopy in the direction of the cervical trunk angle as guide pins in the femoral neck, and the tips of the pins were passed through the fracture line to the subtrochanteric head, and the fluoroscopic frontal and lateral healing was performed again. 1.5 cm, insert the guide needle from the smallest to the largest expanded skin guide cylinder to the bone cortex, leaving the outermost working channel (diameter of about 1.5 cm), drill a hole with the guide needle, fluoroscopic observation of the tip of the guide drill to the femoral head under the soft about 5 mm, pull out the guide drill, measure the length of the nail, tapping, that is, choose the appropriate length of hollow nail screwed, and finally pull out the guide needle. The other two hollow nails were inserted in the same way, and the front and side views were taken again, if there was no abnormality. Then the incision will be sutured and fixed with pressure bandage. The surgery is finished. 1.3 Postoperative recovery Patients can sit up and move around 24 h after surgery, and use antibiotics for 2-3 d. Encourage patients to breathe deeply to facilitate sputum excretion. After the operation, the patient was encouraged to move the muscles of the lower limbs to prevent deep vein thrombosis. If the fracture line is blurred, the affected limb can be partially weight-bearing and exercised after 8-10 weeks of postoperative radiographs. After the fracture reached bony healing, the abductor could be abandoned for full weight-bearing to avoid premature weight-bearing causing femoral head necrosis. 2, Results The time when the hip pain disappeared and the hip joint could be moved actively and passively ranged from 2 to 7 d after surgery, with an average of 3 d. The time when the affected limb could walk with partial weight-bearing ranged from 8 to 21 d, with an average of 16 d. The group was followed up for more than 18 months, of which 39 cases were followed up for more than 36 months. Forty-five fractures in this group achieved bony healing, with a healing rate of 80.4%, and 11 femoral head necrosis (19.6%). The postoperative Harris score of hip function in the fracture healers ranged from 60 to 100, with a mean score of 92.3. 3. Discussion The aim of treatment for femoral neck fracture is to perform functional exercise as early as possible to avoid the occurrence of other complications and deterioration of the primary disease due to prolonged bed rest, on the one hand, and to restore the function of the limb on the other hand. Non-operative treatment is rarely applied due to poor fixation, long bed rest, and many complications [1]. Surgery should be the first choice. At present, clinical surgery is mainly based on internal fixation and artificial hip arthroplasty. Most scholars at home and abroad believe that the efficacy of artificial hip arthroplasty is satisfactory. However, compared with internal fixation, hip replacement is expensive, surgically traumatic, with complications such as infection, dislocation, loosening, and longevity. For Garden I, II and III femoral neck fractures, obtaining fracture healing with strong internal fixation is always better than artificial joints in terms of joint function. Therefore, for most femoral neck fractures, internal fixation is still relevant and should be the preferred treatment modality, especially for young patients. With the improvement of internal fixation techniques, especially the introduction of parallel fixation with multiple hollow nails for intracapsular femoral neck fractures, there are two major problems in clinical treatment: non-healing fracture (about 15%) and ischemic necrosis of the femoral head (20%-30%), so that young and active elderly patients have a better treatment method. Hollow compression screw internal fixation for femoral neck fractures was designed by the Swiss AO school and has been the preferred method of internal fixation for femoral neck fractures in recent years. Its hollow structure allows the insertion of guide pins to be accurately screwed into the femoral neck to provide interfracture compression, which is easy to operate and reliable for fixation. The three hollow screws are distributed in a “pin” pattern between the low pressure trabeculae and the high tension trabeculae to form a derivative-like structure. It is small in size, has a large controllable area, and has a strong anti-rotation ability. The stress generated by the hollow nail is closer to the longitudinal axis, which is conducive to fracture healing. We have changed to a percutaneous internal fixation method based on the standard operation of AO, which can avoid excessive muscle resection and stripping of the tissues below the greater trochanter, with less surgical damage, less bleeding, and less systemic impact. The procedure can even be performed under local anesthesia. Many authors emphasize that early surgery is preferable for femoral neck fractures, and that surgery should be completed within 24 h if possible. If early surgery is not possible, the affected limb should be traction in time to reduce the intracapsular pressure and provide a better internal environment for restoring blood supply and promoting bone healing. However, femoral neck fractures occur in elderly and frail patients with a variety of medical conditions. We believe that the operation time can only be relative. Only by carefully improving all routine examinations, making good perioperative supportive treatment, and allowing patients to operate when their general condition is relatively good, the intraoperative and postoperative risks can be greatly reduced, and serious postoperative heart, lung, brain or other organ complications can be avoided to the maximum extent. Allowing the patient to safely pass through the perioperative period can also reduce the risk to medical staff. Drilling through the cartilage surface of the femoral head with the tip of the guide needle during closed repositioning can have a drainage and decompression effect on the blood accumulated in the capsule. It is beneficial to improve the blood supply to the femoral head and prevent femoral head necrosis [5]. Studies have also confirmed the close relationship between intraosseous hypertension and osteonecrosis, where arterial insufficiency of blood supply after fracture, especially venous stasis, causes intra-femoral hypertension and forms a vicious cycle, and eventually femoral head necrosis via, 2 kerf pins drilled through the cartilage surface of the femoral head and hollow nails screwed along the kerf pins to 0.5 cm below the head, can play a decompression effect on the femoral head and prevent femoral head necrosis.