A prospective, cross sectional descriptive study on all patients had treatment of femoral fracture by SIGN interlocking nail from 03/2016 to 07/2017 at 121 Military Hospital. Patients were observed and followed up closely for 03 months and further for 06 months. There were 60 patients in the study. The ratio of male/female is 2/1. Mean age was 38.27 years old. Traffic accidents made up 80%. Shooting pain at fracture site, absence of movement at broken leg, swollen thigh were found at all patients. Abnormal movements, crepitation and limb deformities occupied 100%. Fracture site of upper 1/3 was 23.3%, middle 1/3 was 60% and lower 1/3 was 16.7%. Static interlocking nailing was 93.3% and dynamic interlocking nailing was 6.7%. The results also showed wound healing (100%), nondisplaced - bone union (98%). 100% patients had good union. General outcomes were very good (94.0%), good (6%) and there were no fair and bad outcomes.Đặc điểm lâm sàng, X quang và đánh giá kết quả điều trị gãy kín thân xương đùi bằng phương pháp đóng đinh nội tủy có chốt kiểu SIGN trên 60 bệnh nhân điều trị tại Bệnh viện Quân y 121 năm 2016 - 2017. Kết quả cho thấy đóng đinh nội tủy có chốt kiểu SIGN là tiêu chuẩn vàng cho điều trị gãy kín thân xương đùi. Đây là kỹ thuật không phức tạp, chi phí điều trị thấp và thời gia nằm viện ngắn.