Evaluation of Geometrical Angles in Lumbo-Sacral Spine on Digital Radiographs in North Indian Population

Abstract

Objectives: The lumbo-sacral spine is the most important region of the vertebral column in terms of its mobility and weight-bearing functions. Measurement of geometrical angles has been used to evaluate the stability of this region. However, there is relative paucity of such data concerning the Indian population. We attempted to study the various angles on digital radiographs in the lumbo-sacral spine in the North-Indian population.Methods: This was a retrospective study in which digital radiographs (lateral view) of the lumbo-sacral spine in 500 subjects with low back pain were evaluated. Patients with history of trauma or radiographically detected bony spinal abnormality were excluded. The lumbar angles measured were lumbo-sacral angle (LSA), Lumbar lordosis angle (LLA), Sacral-inclination angle (SIA) and lumbo-sacral disc angle (LSDA). The demographics and anthropometric parameters were also recorded. Results: The mean values of the angles were: LSA=37.7±8.8; LLA=49.9±6.8; SIA=38.5±7.7and LSDA=12.0±3.9. The results revealed significant higher values for LSA and LLA in females whereas significantly higher values were obtained for LSDA in males. There was a significant correlation observed between the BMI and SIA of the subjects.Conclusion: The mean values of these angles may form the reference values for the North Indian population. Our results show variability when compared to other similar studies, which further strengthen the fact that normal variation in angles of lumbo-sacral region differs among different geographical region and races; hence results of the present study may be of use to for treating different spinal disorders of North Indian population.