Abstract
Purpose: To determine the relationship between sacral morphology and developmental L5/S1 spondylolisthesis in children and adolescent.
Method: A radiographic study was conducted to investigate sacral morphology in developmental L5/S1 spondylolisthesis in a pediatric and adolescent population. The lateral standing radiographs of 131 subjects, aged 6 to 20 years old with developmental L5-S1 spondylolisthesis (91 low grade and 40 high grade) were analyzed with a dedicated software allowing to measure the following parameters, which were analyzed for each subject by the same individual and compared to an age and sex-matched cohort of 120 asymptomatic subjects: the sacral table index (STI), the sacral table angle (STA), the sacral kyphosis (SK), S1 superior angle, S2 inferior angle, and grade of spondylolisthesis. Student t tests were used to compare the parameters between the curve types.
Results: This study demonstrated that STA is significantly smaller (p< 0.01) in children and adolescents with L5-S1 spondylolisthesis compared to a similar control group. Furthermore, STA is significantly smaller in high grade spondylolisthesis when compared to subjects with low grade. There is also a significant difference in segmental sacral morphology (S1 and S2 anatomy) in the spondylolisthesis group. Increasing sacral kyphosis is also found to be significantly associated with spondylolisthesis.
Conclusion: The sagittal sacral morphology is a constant anatomic variable specific to each normal individual. The anatomy of the sacrum in children and aldolescentss with L5-S1 spondylolisthesis is particular and different from a control group. This study suggests that sacral anatomy may have a direct influence on the development of spondylolisthesis: a lower STA and higher sacral kyphosis may be two factors predisposing to vertebral slip in developmental spondylolisthesis.
Correspondence should be addressed to Meghan Corbeil, Meetings Coordinator Email: meghan@canorth.org
