Comparison of a semiquantitative and a quantitative method for assessing vertebral fractures in osteoporosis

There is no agreed definition for the assessment of vertebral fractures and deformities in patients with osteoporosis. Radiographs of 66 patients randomized for therapy with etidronate or placebo were analyzed at baseline and during follow-up (60/120/150 weeks) independently using two procedures. The first method of spinal deformity index (SDIG) and vertebral deformity score (VDSG) is based on a semiquantitative visual reading of each vertebra between T4 and L4. The second method of spine deformity index (SDIM) and vertebral deformity index (VDIM) is based on vertebral height measurements of T4 through L5 and each measurement from T5 to L5 (anterior, middle and posterior height) is related to T4 and compared with the respective T4-related normal range. There was good agreement between the mean vertebral deformation from T5 to L4 graded by VDSG and VDIM, with correlation coefficients between R = 0.52 (p < 0.0001) and R = 0.9 (p < 0.0001) respectively. Spinal deformation at baseline as measured by SDIM and SDIG was correlated with R = 0.76 (p < 0.0001). For diagnosing a vertebra as fractured or not, VDIM reached a sensitivity of 82% and a specificity of 85% using VDSG as a standard, and on the other hand VDSG reached a sensitivity of 78% and a specificity of 88% in relation to VDIM. The changes in spinal deformation from week 0 to 150 were correlated with R = 0.58 (p < 0.0002) between SDIM and SDIG. To detect vertebral fracture progression the sensitivity of VDIM was 74% and the specificity 86%, when changes in VDSG were used as a standard.(ABSTRACT TRUNCATED AT 250 WORDS)