The relation between sagittal morphology of the lumbosacral spine and the degree of lumbar intervertebral disc degeneration

Objectives: We investigated the relationship between the lumbosacral morphology and degree of intervertebral disc degeneration in a large sample of young patients. In addition, the relation between various morphological parameters (sacral table angle and sacral kyphosis) and lumbar disc herniation or degeneration was also evaluated. Methods: The magnetic resonance imaging (MRI) of low back pain patients referred to our department in 2008-2009 were retrospectively evaluated. Patients with prior lumbar spinal surgery, serious congenital anomalies on MRI, incomplete or complete lumbosacral trancision, severe scoliosis, spondylolysis, or spondylolisthesis were excluded from the study. A sample of 131 females between 20-30 years of age was studied. Patients were evaluated for the presence of intervertebral disc herniation or degeneration, and the degree of degeneration was assessed. Angles of lumbar lordosis, sacral table, and sacral kyphosis were also measured for each patient. Results: The degree of intervertebral disc degeneration increased in parallel to the decrease in the sacral kyphosis and lumbar lordosis angles, and to the increase in sacral table angle. A statistically significant difference with regard to the angles of lumbar lordosis, sacral kyphosis, and sacral table was determined between individuals with (23.37 +/- 7.09 degrees, 163.09 +/- 9.48 degrees, 104.34 +/- 5.47 degrees, respectively) and without intervertebral disc degeneration (26.94 +/- 7.39 degrees, 168.94 +/- 10.52 degrees, 100.83 +/- 4.32 degrees; p=0.006, p=0.001, p=0.0001, respectively). In addition, a statistically significant difference with regard to the angles of lumbar lordosis, sacral kyphosis, and sacral table was determined between individuals with (22.82 +/- 6.94 degrees, 162.23 +/- 9.53 degrees, 104.94 +/- 5.19 degrees, respectively) and without intervertebral disc herniation (27.25 +/- 7.26 degrees, 169.39 +/- 9.96 degrees, 100.48 +/- 4.33 degrees; p=0.001, p=0.0001, p=0.0001, respectively). Conclusion: The degree and risk of intervertebral disc degeneration and herniation increases in parallel to the decrease in sacral kyphosis and lumbar lordosis, and to the increase in sacral surface angle.