Background Many investigators advocate anterior release combined with halo-femoral traction and posterior fusion when treating stiff thoracic curves in patient with adolescent idiopathic scoliosis (AIS).But the anterior operations often induce severe complications.Some surgeons choose posterior-only surgery with halo-femoral traction,posterior wide release and correction.But to the best of our knowledge,there are only rare prospective studies on these posterior-only surgeries for AIS patients who have a rigid curve more than 80° and flexibility less than 35％.@@Methods Sixty-four AIS patients were recruited from September 2006 to June 2009.All patients had rigid curves and underwent spinal correction.They were randomly divided into group A (combined anteroposterior surgery) and group B (posterior-only surgery).Images and scoliosis research society-22 questionnaire (SRS-22) scores were performed praand post-operation and during follow-up visits.The operation time,blood loss,hospital days,and hospital charges were compared between the two groups.@@Results These patients were followed for an average of 37.5 months (range,24-65 months).No serious complications were observed.There were no significant differences between the two groups in gender,age,preoperative radiographic data,or preoperative SRS-22 score.The average operation time,blood loss,hospital days and hospital charges in group B were less than those in group A.The SRS-22 score in group B was better than in group A at post-operation and at final follow-up.@@Conclusions In AIS with a rigid curve more than 80° and flexibility less than 35％,strong halo-femoral traction with wide posterior spinal release and three dimensional spinal correction can provide better SRS-22 scores,comparable curve correction,shorter operation time,less blood loss,shorter hospital stays and lower charges when compared to combined anterior and posterior surgery.