BackgroundMany factors effect on management (surgical and nonsurgical) of adolescent idiopathic scoliosis (AIS).ObjectivesThe purpose of this study was evaluation of the effects of generalized ligamentous laxity (GLL) on surgical treatment of AIS.Materials and Methods72 patients with AIS were studied between 2002 and 2009. 24 cases (33.4%) were placed in group A (normal) while 48 patients (66.6%) with GLL in group B. Our threshold for adding anterior approach was a curve which could not be corrected to < 50° on the supine lateral bending view.ResultsThe mean age and follow up period were 16.4 (12-22 years) and 3.8 (2-6.5 years), respectively. In the first group, 12 (50%) were operated with combined anterior and posterior approaches while in the later; there were only 6 (12.5%). Curve correction was 73.3% in patients with GLL and 57.1% in patients without it. Both of these differences were significant statistically (P = 0.001).ConclusionsIn preoperative planning of surgical treatment of AIS, GLL is an important factor. In this special group of patients due to much more flexibility, relatively larger scoliotic curves can be safely treated by single posterior approach.