Clasificación de la enfermedad degenerativa del disco lumbar de Thalgott: Reproducibilidad intraobservador e interobservador

Background: Determine the inter/intra-observer correspondence in the Thalgott classification for degenerative disc disease (DDD) of the lumbar spine. Methods: Seven observers participated in this study, 4 spine surgeons and 3 spine fellows. Twenty two different cases of degenerative disc diseases of the lumbar spine were analyzed. The classification system uses MRI, provocative discography and plain anteroposterior and lateral radiographs. The Kappa test was used for statistic analysis. Results: Inter-observer correspondence in the first round was 22.7% CI 95% 7.8-45.4%. In the second evaluation there was a difference within the anterior column (27.3% CI 95% 10.7-50.2%) and the facet joint (18.2% CI 95% 5.2-40.3%).Intra-observer correspondence in the global evaluation of the classification was Kappa 0.72 (CI 95% 0.50-0.93). When considering only the anterior column, it was Kappa 0.76 (CI 95% 0.54-0.97) and for the posterior column it was Kappa 0.66 (CI 95% 0.31-1). Conclusions: Global interpersonal concordance for both the anterior and posterior column was poor while intraobserver concordance was good. The correspondence of the disc itself was better than the facet joint. There was a difference regarding observers’ experience, where the eldest obtained better results. We think that the anterior column classification system should be easier, and that a CT may be necessary to classify the facet joint in order to obtain better results in the reliability of this classification; where the DDD of the lumbar spine is understood, classified and validated in order to use a common language, i.e. a helpful tool to decide the best treatment. Introducción: Se determinó la concordancia interobservador e intraobservador del sistema de clasificación de la enfermedad degenerativa del disco lumbar según Thalgott y cols. Materiales y métodos: En este trabajo participaron 7 observadores (4 ortopedistas especialistas en cirugía espinal y 3 médicos concurrentes). Se analizaron 22 discos intervertebrales lumbares de 15 pacientes. Se evaluaron: radiografías (frente, perfil, dinámicas), resonancia magnética (cortes sagitales y axiales en tiempos T1-T2) y discografía. Se utilizó el índice kappa para la evaluación estadística. Resultados: Concordancia interpersonal: la primera medición disco-faceta fue 22,7% IC 95% 7,8-45,4%; en la segunda medición hubo diferencias entre disco (27,3% IC 95% 10,7-50,2%) y faceta (18,2% IC 95% 5,2-40,3%). Concordancia intrapersonal: el valor hallado e