Abstract: Objective: To investigate the effectiveness and safety of internal fixation combined with interlocking intramedullary nail under different reduction in the treatment of femoral shaft fractures.Methods: Seventy-one patients with femoral shaft fractures were divided into the open reduction group(n=34) and close reduction group(n=37) according to different reduction methods.The open reduction group and close reduction group were treated with open reduction combined with interlocking intramedullary nail fixation,and close reduction combined with interlocking intramedullary nail fixation,respectively.Two groups were followed up for 12 months.The operation index,clinical efficacy and complications were compared between two groups.Results: The intraoperative blood loss,fracture healing time in close reduction group were significantly lower than those in open reduction group(P<0.01).After 12h,24h,48h and 72h,the VAS scores in close reduction group were lower than that in open reduction group(P<0.05 to P<0.01).The clinical effect in close reduction group after 12 months of operation was better than that in open reduction group(P<0.05).The incidence rate of complication in reduction group(5.41%) was significantly lower than that in open reduction group(23.53%)(P<0.05).Conclusions: The effect of close reduction combined with interlocking intramedullary nail fixation in treating the femoral shaft fractures is better than that of open reduction.The close reduction combined with interlocking intramedullary nail fixation can promote the fracture healing and knee joint function recovery,and reduce the occurrence of complications.