Evaluation of computed tomographic methods to measure vertebral rotation in adolescent idiopathic scoliosis: an intraobserver and interobserver analysis.

The purpose of this study was to compare three computed tomography (CT) measurement methods that have been described by Aaro-Dahlborn, Ho, and Krismer et al. The methods were based on clinical, intraobserver, and interobserver analysis. Twenty-five patients with adolescent idiopathic scoliosis were studied for clinical reliability of these methods. There was a significant correlation between Aaro-Dahlborn and Ho's methods (p < 0.02), and there was no correlation between Krismer's method and the other two (p > 0.05). Intraobserver analysis was performed by one observer at 20 different times, and interobserver analysis was performed by 20 orthopedic surgeons on the same CT scan. Intraobserver and interobserver analysis has shown that the method described by Ho is the most reliable one. Consequently, Ho's method is the most reliable and clinically the most useful method for measuring the vertebral rotation in adolescent idiopathic scoliosis.