Objective To investigate the early clinical efficacy of Masquelet membrane induction technique in the treatment of traumatic long bone defects.Methods A retrospective case series study was conducted to analyze the clinical data of 41 patients with traumatic long bone defects admitted to the General Hospital of the Northern Theater Command from January 2012 to April 2017.There were 36 males and five females,aged 15-70 years,with an average of 38.2 years.There were 20 patients with bone defect at the femur,19 at the tibia,one at the fibula,and one at the ulna.All patients received staged treatment using the Masquelet membrane induction technique.In stage Ⅰ surgery,thorough debridement was first performed,and the secretions were taken for bacterial culture.The average bone defect length after debridement was 6.9 cm (2.0-18.5 cm).The bone defect was filled with antibiotic bone cement to induce the biofilm formation.If the postoperative bacterial culture showed positive results,debridement surgery was performed again.Stage Ⅱ surgery was performed after 6-12 weeks.The white blood cell count,C-reactive protein (CRP),procalcitonin (PCT),erythrocyte sedimentation rate (ESR) were measured before the operation.During the operation,bone biopsy was performed,and the bone cement placeholder was completely removed.The autologous cancellous bone and artificial bone were implanted in the bone defect areas,and the induced membrane was sutured.The healing time of bone defects was recorded,and the Paley fracture healing scoring criteria were used to evaluate the limb function.The complications were observed.The inflammatory markers were reviewed at the last follow-up.Results All patients were followed up for 7-36 months with an average of 13.6 months.A total of 37 patients obtained bone healing.The fracture healing rate of stage Ⅰ was 90％,and the healing time was 6-13 months,with an average of 9 months.According to the Paley fracture healing scoring criteria,the results were excellent in 25 patients,good in 10,and fair in two patients,with the excellent and good rate of 85％.In terms of complications,one patient with superficial infection recovered after dressing change,three patients had deep infection,of which one patient was treated with amputation and two received other treatments,and three patients were treated with membrane induction again because of bone resorption.At the last follow-up,there were significant differences between preoperative and postoperative White blood cell count,CRP,PCT and ESR(P ＜ 0.05).Conclusion For traumatic long bone defects,Masquelet membrane induction technique can promote fracture healing,restore limb function and reduce complications.