The sagittal profile of the cervical and lumbosacral spine in Scheuermann thoracic kyphosis

Abstract

The sagittal profiles of the cervical and lumbar spine have not been studied in Scheuermann kyphosis. The purpose of this study was to investigate these profiles. Standing lateral radiographs of the spine in 34 children with Scheuermann kyphosis were reviewed. Cervical lordosis, lumbar lordosis, thoracic kyphosis, sagittal vertebral axis, and sacral inclination were measured. The relations between these variables were explored using the Pearson correlation. The average patient age was 15.5 +/- 1.8 years, thoracic kyphosis was 65 degrees +/- 12 degrees, lumbar lordosis 71 degrees +/- 13 degrees, and cervical lordosis 4 degrees +/- 15 degrees (Cobb angle), and 9 degrees +/- 14 degrees (posterior vertebral body angle [PVBA]). No correlations were noted between cervical lordosis and thoracic kyphosis. Correlations were noted between cervical lordosis and lumbar lordosis (r2 = 0.17, Cobb angle; r2 = 0.16, PVBA) and between cervical lordosis and the residual sagittal difference (thoracic kyphosis minus lumbar lordosis; r2 = 0.32, p = 0.001 [Cobb angle], and r2 = 0.19, p = 0.01 [PVBA]). In Scheuermann kyphosis, the flexible cervical and lumbar spine is linked by the intermediate rigid thoracic segment. As the residual sagittal difference becomes more kyphotic, lordosis of the cervical spine increases as the patient strives to maintain a forward visual gaze.