The influence of fracture mechanism and morphology on the reliability and validity of two novel thoracolumbar injury classification systems

Abstract

Study design: The Thoracolumbar Injury Severity Score (TLISS) and the Thoracolumbar Injury Classification and Severity Score (TLICS) were prospectively evaluated.

Objectives: To compare the reliability and validity of the TLISS and TLICS schemes to determine the importance of injury mechanism and morphology to the identification and treatment of thoracolumbar fractures.

Summary of background data: Two novel algorithms have been developed for the categorization and management of thoracolumbar injuries: the TLISS system emphasizing injury mechanism and the TLICS scheme involving injury morphology.

Methods: The clinical and radiographic findings of 25 patients with thoracolumbar fractures were prospectively presented to 5 groups of surgeons with disparate levels of training and experience with spinal trauma. These injuries were consecutively scored, first using the TLISS and then 3 months later with the TLICS. The recommended treatments proposed by the 2 schemes were compared with the actual management of each patient.

Results: For both algorithms, the interrater kappa statistics of all subgroups (mechanism/morphology, status of the posterior ligaments, total score, predicted management) were within the range of moderate to substantial reproducibility (0.45-0.74), and there were no statistically significant differences noted between the respective kappa values. Interrater correlation was higher for the TLISS paradigm on mechanism/morphology, integrity of the posterior ligaments, and proposed management (P < or = 0.01). The TLISS and TLICS schemes both exhibited excellent overall validity.

Conclusions: Although both schemes were noted to have substantial reproducibility and validity, our results indicate the TLISS is more reliable than the TLICS, suggesting that the mechanism of trauma may be a more valuable parameter than fracture morphology for the classification and treatment thoracolumbar injuries. Since these injury characteristics are interrelated and are critical to the maintenance of spinal stability, we think that both concepts should be considered during the assessment and management of these patients.