Surgical treatment of adolescent idiopathic scoliosis: a comparative study of two segmental instrumentation systems.

This study compares two different surgical techniques and instrumentation types in the treatment of adolescent idiopathic scoliosis. The charts and radiographs of 116 patients with adolescent idiopathic scoliosis treated by posterior spine fusion with Isola or Cotrel-Dubousset instrumentation were reviewed. Patients were separated into two equivalent groups matched for age, sex, curve type, and curve magnitude. All patients had a minimum of 2 years follow-up. The instrumentation in group 1 consisted of hooks, wires, and pedicle screws. That used in group 2 was limited to hooks and rods. The Mann-Whitney, Wilcoxin, and the paired Student t tests for matched pairs were used for statistical analysis. Patients in group 1 had increased curve correction (66% vs. 52%), apical vertebral translation (63% vs. 30%), and correction of the end vertebral tilt angle (11 degrees vs. 3 degrees) (p < 0.001). The percentage of coronal curve correction in curves larger than 65 degrees also was greater in group 1 (59% vs. 40%). Physiologic sagittal alignment was obtained in 80% of the patients in group 1 and 25% in group 2. No major complication or pseudoarthrosis occurred in either group. This study supports improved correction of curve magnitude, apical translation, and end vertebral tilt angle with the use of multiple anchor types compared with the correction achieved with standard hook-and-rod constructs.