Comparison between methods of assessing lumbosacral curve obtained by radiographic image

OBJECTIVE To investigate the correlation between different radiographic methods in the evaluation of the lumbosacral concavity. METHODS The sample consisted of 52 individuals with ages ranging from 18 to 28 years old. The procedures related to radiographic image collection were carried out in collaboration with a diagnostic imaging center of a hospital in Curitiba, PR, Brazil. The angles of the lumbosacral concavity were evaluated by the following methods: Centroid, Cobb1L1-S1, Cobb2L1-L5, Cobb3L2-S1 Cobb4T12-S1, Posterior Tangent and Trall. RESULTS High correlation coefficients (r ranging from 0.77 to 0.89) were found among variations of the Cobb method. Additionally, we propose a categorical classification of angle values obtained by each method. We also analyzed the influence of the level of the inflection point between the lumbar lordosis and thoracic kyphosis in determining the evaluation method to be used. The inflection point had a higher incidence in the region between the twelfth thoracic vertebra and the first lumbar vertebra (63.5%). CONCLUSION The correlation and agreement between methods vary considerably. Moreover, the thoracolumbar inflection point should be considered when choosing the method of assessing patients.