Intraobserver and interobserver reliability of the New AOSpine Thoracolumbar Spine Injury Classification System

English Keywords:Spinal injury  Classification  Thoracolumbar  Reliability

English Abstract:

  【Abstract】 Objectives: To evaluate the intraobserver and interobserver reliability and main influencing factors of the New AOSpine Thoracolumbar Spine Injury Classification System. Methods: Seventy thoracolumbar fracture patients with complete clinical data and radiologic data(including X-ray films, CT and MRI) were enrolled. Five observers were assigned to independently determine the classifications according to the New AOSpine Thoracolumbar Spine Injury Classification System. If there was a observer in a different type, it was identified as inconsistent. After a 6-week interval, the 70 cases were presented in a random sequence to the same evaluators for repeated evaluation. The Cohen Kappa coefficient(K) was used to determine the interobserver and intraobserver reliability. Results: The New AOSpine Thoracolumbar Spine Injury Classification System was found to have fair interobserver reliability and excellent intraobserver reliability. The interobsever and intraobsever reliability was Kappa=0.602 and Kappa=0.782, respeclively. The compression fracture(A type) and translation injury(C type) demonstrated fair interobserver reliability and excellent intraobserver reliability. The interobserver reliability was Kappa=0.604 and Kappa=0.662 respectively, while the intraobserver reliability was Kappa=0.787 and Kappa=0.761 respectively. The AO System had poor reliability in evaluation of the tension band injuries(B type). The interobserver reliability was Kappa=0.362 and the intraobserver reliability was Kappa=0.657. The interobserver reliability of the overall subtypes was Kappa=0.526 and the intraobserver reliability was Kappa=0.701, in which the poorest reliability in evaluation was the subtype of B2. The interobserver reliability was Kappa=0.214 and the intraobserver reliability was Kappa=0.633. Followed was the subtype of A4. The interobserver reliability was Kappa=0.322 and the intraobserver reliability was Kappa=0.685. Conclusions: The new AOSpine Thoracolumbar Spine Injury Classification System has fair interobserver reliability and excellent intraobserver reliability. The poor reliabilities in evaluation of the subtypes A4 and B2 are the main reason for disagreement in this system.