Computer-assisted curvature assessment and Cobb angle determination of the thoracic kyphosis. An in vivo and in vitro comparison.

Abstract

A retrospective survey of thoracic spinal curvature compared postmortem radiographs with recent clinical films in 22 cases. This study was performed to determine whether spinal curvature measured from postmortem radiographs is a valid measure of curvature in vivo. Little quantitative data have been cited on whether sagittal plane thoracic spinal curve characteristics change after death. Thoracic kyphosis was measured using the Cobb method and the mean radius of curvature from computer-assisted digitizing of the vertebral contour. Thoracic segments visualized on the chest films were referenced to the postmortem radiograph. The in vivo and in vitro measurements strongly correlated (Cobb angle r = 0.95, curvature r = 0.78). Trends decreased slightly in Cobb angle (1.3%, -2.6%) and increased slightly in curvature (10.7 mm, 4.1%). Differences were not significant, however, supporting the use of spinal curvature analysis with postmortem radiographs.