ObjectiveTo explore the efficacy and advantages of the lower extremity axial distractor assisted closed reduction and retrograde intramedullary nail internal fixation in the treatment of distal femoral fractures.MethodsThe clinical data of 49 patients with distal femoral fractures treated with retrograde intramedullary nail internal fixation between April 2016 and December 2018 were retrospectively analyzed. According to the different methods of intraoperative reduction, the patients were divided into trial group (29 cases, using lower extremity axial distractor to assist closed reduction) and control group (20 cases, using free-hand retraction reduction). There was no significant difference in general information between the two groups (P>0.05), such as gender, age, side of injury, cause of injury, and fracture classification. The operation time, intraoperative blood loss, intraoperative fluoroscopy frequency, and callus formation time were recorded and compared between the two groups. The function of the affected limb was evaluated according to the Schatzker-Lambert standard at 1 year after operation.ResultsAll patients successfully completed the operation. In the control group, there was 1 case with open reduction and internal fixation, and the rest of the two groups were closed reduction. There was no significant difference in operation time, intraoperative blood loss, and intraoperative fluoroscopy frequency between the two groups (P>0.05). There was no complication such as vascular or nerve injury and iatrogenic fracture, etc. during and after operation, and the incisions healed by first intention. Except for 2 patients in the trial group who were lost to follow-up at 3 months after operation, the rest of the patients were followed up 12-36 months, with an average of 16.0 months. There was no significant difference in the callus formation time between the two groups (t=2.195, P=0.145). During the follow-up, postoperative knee joint stiffness occurred in 1 case in the control group, which improved by strengthening the knee joint function exercise and removing the internal fixator; the rest were not found to be associated with delayed or nonunion fractures, knee stiffness, and internal fixation complication. The function of the affected limb was evaluated according to the Schatzker-Lambert standard at 1 year after operation, the trial group achieved excellent results in 22 cases, good in 4 cases, and fair in 1 case, with an excellent and good rate of 96.3%; in the control group, the results were excellent in 16 cases, good in 3 cases, and fair in 1 case, with an excellent and good rate was 95.0%; showing no significant difference in the excellent and good rate between the two groups (χ2=0.451, P=0.502).ConclusionThe lower extremity axial distractor assisted closed reduction and retrograde intramedullary nailing for the treatment of distal femoral fractures is convenient, which has satisfactory efficacy.