［Objective］To explore the safety,feasibility and clinical effect of the treatment of lumbar isthmus in adolescents by using the combination of bone grafting and percutaneous pedicle screw fixation.［Methods］From June 2015 to October 2018,13 adolescent patients with spondylolysis were selected from the First Affiliated Hospital of Guangxi University of traditional Chinese medicine,including 8 males and 5 females,aged 17-28 years with an average of 23.4±4.3 years. Among them,7 cases of L5 bilateral isthmus,5 cases of L4 bilateral isthmus and 1 case of L3 bilateral isthmus.The degree of meyerding's slippage: Grade I in 6 cases, no obvious slippage in the other 7 cases.Pfirrmann classification of intervertebral disc:8 cases of Grade A,5 cases of grade B.VAS score was 1.35±0.45.ODI score was 15.60±5.25.All cases were treated by isthmus treatment under posterior foramen and autogenous iliac bone grafting,percutaneous pedicle screw fixation under C-arm fluoroscopy,VAS score,ODI score and modified macnab standard.［Results］There was no infection, necrosis of the skin margin,loosening of internal fixation, fracture and other complications.The VAS score of lumbago in the last follow-up was 7.35±1.62,ODI score was 75.60±7.35, which was better than that before operation.The difference was statistically significant(P<0.05).At the last follow-up,CT showed that all the isthmus bone grafts had bone fusion,the fusion time ranged from 7.5 to 23.5 months,with an average of 12.5±3.5 months.According to the improved macnab standard,9 cases were excellent,3 cases were good,1 case was fair and 0 case was poor.The excellent and good rate was 100%. ［Conclusions］The treatment of lumbar isthmus in adolescent patients was performed by the combination of bone grafting and percutaneous pedicle screw fixation,In line with the current development direction of minimally invasive spine surgery,it has the advantages of small trauma,less complications and fast recovery.It is a minimally invasive and effective method for the treatment of juvenile isthmus,which is worthy of clinical promotion.