Objectives:To evaluate the early efficacy of Dynesys corrective internal fixation system in the treatment of Lenke1 and Lenke5 adolescent idiopathic scoliosis(AIS).Methods:A retrospective analysis was conducted on 15 AIS patients(4 males and 11 females)who underwent Dynesys corrective and internal fixa-tion treatment in our department from November 2019 to September 2023.The average age of the patients was 15.5±2.2 years(12-21 years).Among the patients,there were 5 cases of Lenke1 type and 10 cases of Lenke5 type,mainly characterized by thoracolumbar deformities.The operative time,bleeding volume,and complications were recorded by reviewing medical records,and imaging data were measured and analyzed.The measurement indicators included Cobb angle,thoracic kyphosis,lumbar lordosis,and lumbar range of mo-tion at preoperation,first follow-up within 1 week after surgery,and final follow-up to evaluate the corrective effect of posterior Dynesys corrective internal fixation on scoliosis.Results:All the patients successfully com-pleted the surgery and were followed up for 3-48 months.The average operative time was 280.8±45.8min,average bleeding volume was 194.0±145.5mL,the number of main curvature segments was 4.7±1.1,and the number of operative segments was 4.7±1.1.The Cobb angle of the coronal plane was 40.8°±5.5° before surgery,5.5°±4.5° after surgery,and 7.6°±5.5° at final follow-up.Coronary scoliosis improved significantly af-ter surgery(P＜0.05),with a total correction rate of 86.9％for the main curvature,89.8％for Lenke1 type,and 85.4％for Lenke5 type.There was no significant statistical difference between the two types.At final follow-up,the range of motion of the thoracolumbar fixed segment was 8.2°±3.1°.All patients did not experience any operation-related complications,and no implant complications such as loose screws or broken ropes were found during follow-up.Conclusions:Dynesys corrective internal fixation surgery can effectively correct Lenke1 and Lenke5 AIS,with minimal surgical trauma,fast postoperative recovery,preservation of partial spinal motor function,which has satisfactory early postoperative outcomes.