【Abstract】 ObjectiveTo investigate and compare the clinical outcome of internal fixation by two or three cannulated screws for femoral neck fracture, and analyze the risk factors for femoral head necrosis after internal fixation. Method133 patients receiving cannulated screw fixation for fresh femoral neck fractures were divided into two groups. Among them, 75 cases in group A were fixed by two screws, 58 cases in group B were treated by three screws. The medical data including demographic data, operation time, blood loss, frequence of Xray exposure, duration of hospitalization, time to union, complication rate, Harris hip joint functional score were recorded. The correlation between garden classification and femoral head necrosis was analyzed too. Results125 of 133 patients were followed up for 20-36 months. No differences were observed between two groups in hospital stay, time to union, perioperative complication rate, harris hip joint functional score, femoral head necrosis rate (P＞0.05). Patients in group A had less invasive incision, shorter operation time, less blood loss compared with those in group B (P＜0.05). The number of cannulated screw was not significantly associated with femoral head necrosis, while Garden classification (P=0.012) was significantly associated with femoral head necrosis. Femoral neck fractures of type Garden Ⅲ and Ⅳ were more susceptible to femoral head necrosis. ConclusionPercutaneous internal fixation with cannulated screws was an effective treatment for femoral neck fracture, and fixation with two screws has the advantages of less invasiveness, radiation exposure, bleeding, and so on. Garden classification, but not the number of screws is shown to be related to femoral head necrosis.

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