Patients with femoral neck fractures tend to have mild hip flexion and knee flexion and external rotation deformities. Fractures of the femoral neck often occur in the elderly, and their incidence increases as people live longer, most often between the ages of 50 and 70. There are 2 basic factors that cause fractures in the elderly, endogenous bone strength decreases, mostly due to osteoporosis; double-quantum densitometry confirms that the number of tension trabeculae in the femoral neck becomes thinner, decreases or even disappears, and finally the number of pressure trabeculae also decreases, together with the dense trophoid vascular pores in the upper femoral neck area (mean 14.6 ± 0.22 standard deviations of 3.1 according to 200 adults with observed measurements in the upper femoral neck area), both of which can make weaken the biomechanical structure of the femoral neck and make it vulnerable. So, how to diagnose it? 1. Symptoms Elderly people complaining of hip pain after a fall and afraid to stand and walk should think of the possibility of femoral neck fracture. 2.Signs The affected limb mostly has mild hip flexion and knee flexion and external rotation deformity. In addition to the spontaneous pain in the hip, the pain is more obvious when moving the affected limb. The hip is also painful when the heel of the affected limb or the greater trochanter is tapped, and there is often pressure pain below the midpoint of the inguinal ligament. Femoral neck fractures are mostly intracapsular fractures with little bleeding after the fracture and surrounded by extra-articular thick muscles, so local swelling is not easily visible in appearance. Patients with displaced fractures are unable to sit up or stand after the injury, but there are some cases of nondisplaced linear fractures or insertional fractures that can still walk or ride a bicycle after the injury. Special attention should be paid to these patients. Do not turn a nondisplaced stable fracture into a displaced unstable fracture by missing the diagnosis. The affected limb is shortened in displaced fractures, where the distal end is displaced upward by muscle traction. The affected side of the greater trochanter is elevated, as shown by the greater trochanter being above the iliac-sciatic tuberosity line (Nelaton line); the horizontal distance between the greater trochanter and the anterior superior iliac spine is shortened and shorter than that of the healthy side. History of trauma, hip pain, inability to stand and walk, typical hip flexion, knee flexion and external rotation deformity of the affected limb, the affected greater trochanter is above the Nelaton line, the horizontal distance between the greater trochanter and the anterior superior iliac spine is shorter than that of the healthy side, X-ray and CT examination can establish the diagnosis.