BACKGROUND:Standing bending, supine bending, lateral pressing, pronation compression films and traction radiography are indeed effective to predict the correction outcome of surgeries by Harrington's method and Lugue's method,however, they are discontented for the correction of three-dimensional pedicle screw of vertebral arch.OBJECTIVE: To evaluate the role of preoperative X-ray films of gravity-suspending traction, supine bending and fulcrum bending in patients undergoing spinal three-dimensional correction and fusion for adolescent idiopathic scoliosis (AIS).DESIGN: Contrast observation.SETTING: Department of Orthopaedics, the 211 Hospital of Chinese PLA (Military Orthopaedics Center).PARTICIPANTS: From January 2003 to December 2005, 63 cases aged 10-21 years were recruited from Department of Orthopaedics in the 211 Hospital of Chinese PLA, including 18 males and 45 females. They were diagnosed as AIS by clinical examinations and X-ray film, with Cobb angle≥40°. Informed consents were obtained from all the subjects.METHODS: All of the 63 AIS cases with 79 structural curves were studied by preoperative X-ray films of standing,gravity-suspending traction, supine bending and fulcrum bending, which were compared with standing X-ray films one week postoperatively.MAIN OUTCOME MEASURES: Cobb angles of preoperative fulcrum bending film and postoperative standing film.RESULTS: All of the 63 cases were involved in the result analysis. There was no significant difference in the Cobb angle between preoperative fulcrum bending X-ray film and postoperative standing X-ray film (P ＞ 0.05). Gravity-suspending traction and supine bending films were significantly different from postoperative standing film (P ＜ 0.05).CONCLUSION: The fulcrum bending X-ray films are superior to gravity-suspending traction and supine bending films in predicting the postoperative correction of AIS patients.