Goh S, Price RI, Leedman P, Singer KP (2000) A comparison of three methods for measuring thoracic kyphosis: Implications for clinical studies. Rheumatology. 39: 310-315

Abstract

Objectives: To compare the Cobb technique for measuring kyphosis with an alternative method and a computer assisted curve assessment technique, and to examine the influence of vertebral body and disc shape on kyphosis.

Methods: Kyphosis measurements were derived from 93 lateral spinal radiographs or sagittal CT images of cadaveric spines, using [i] a computer-assisted method for estimating radius of curvature, [ii] the traditional Cobb method, and [iii] an alternative Cobb method. Regression models were applied for agreement analyses, and to examine the relative contribution of vertebral body and disc shape on the extent of curvature.

Results and Conclusions: Strong associations existed between curvature and angle data derived from the three methods, confirming the clinical utility of these techniques for quantification of thoracic kyphosis. However, the traditional Cobb method tended to over-estimate kyphosis in the presence of vertebra; body end-plate deformation. The degree of kyphosis was strongly reflective of the extent of deformity of the vertebral bodies, and to a lesser extent the shape of the thoracic discs.