Further evaluation of the Walter Reed Visual Assessment Scale: correlation with curve pattern and radiological deformity

BACKGROUND The Walter Reed Visual Assessment Scale (WRVAS) was designed to measure physical deformity as perceived by patients with idiopathic scoliosis. Previous studies have shown that the instrument has excellent internal consistency and a high correlation with the radiological magnitude of scoliotic curves. Nonetheless, it is not known whether the scale can discriminate between the various curve patterns of the deformity, or whether the deformities represented in the scale's drawings relate to the corresponding radiological deformities. METHODS This study included 101 patients (86 women and 15 men; mean age 19.4 years) with idiopathic scoliosis. In a single visit, patients underwent standing PA radiography of the spine and completed the WRVAS. X-ray measurements included: 1) magnitude (Cobb angle) of the proximal thoracic curve (PT), main thoracic curve (MT), and thoracolumbar/lumbar curve (TL/L); 2) difference in shoulder level; 3) T1 offset from the central sacral line (T1-CSL); 4) apical vertebra (apV) rotation at the MT and TL/L curves and 5) apical vertebra offset of the MT and TL/L curves from the central sacral line. A variable designated Cobbmax was defined as the largest angle of the three curves (PT, MT or TL/L). Patients were grouped onto three patterns: Thoracic (TH Group)(n = 30, mean MT 42.1 degrees , TL/L 20.9 degrees ); double major (DM Group) (n = 39, mean MT 38.6 degrees , TL/L 34.4 degrees ) and thoracolumbar (TL Group)(n = 32, mean MT 14.3 degrees , TL/L 25.5 degrees ). The magnitude of the curves in the TL Group was significantly smaller than in the other groups (P < 0.05). The Spearman partial correlation coefficient was determined between the score for each WRVAS question and the curve pattern, adjusting for the Cobbmax variable. The Spearman correlation coefficient was determined between the WRVAS items and shoulder imbalance, T1-CSL offset, MT Cobb angle, MT apV rotation, MT apV offset, PT Cobb, TL/L Cobb, TL/L apV rotation and TL/L apV offset. RESULTS The median (interquartile range) of the total WRVAS score was 14 (IQR 6). No correlation was found between the curve pattern and the various scores on the scale (partial correlation coefficients ranged from -0.16 to 0.12). WRVAS drawings for items 1, 2, 4 and 7 correlated satisfactorily with the corresponding radiological measurements (correlation coefficients, 0.62, 0.3, 0.48 and 0.53, respectively). Items 3, 5 and 6 did not correlate with the radiological measurements (correlation coefficients -0.06, -0.07 and 0.05, respectively). CONCLUSION The profile of the individual WRVAS scores does not differentiate among specific curve patterns (thoracic, double major and thoracolumbar/lumbar). Moreover, some of the drawings (items 3, 5 and 6) do not correlate with the radiological deformity they were designed to measure.