Measurement of sagittal imbalance in patients with lumbar degenerative pathology

Abstract

Introduction: Degenerative diseases of the lumbar spine (DSD) are a major cause of disability worldwide characterized by degeneration associated with age leading to low back pain and functional impairment. The study of lumbar degenerative spine diseases has increased the significance of sagittal balance. Sagittal imbalance occurs when there is disturbance in alignment between spinal and pelvic parameters, which triggers compensatory mechanisms that subsequently fail leading to significant disability. Understanding these relationships provides insight into improving patient management and outcomes in LBD. Primary Objectives: This was a descriptive study aimed at: Describing sagittal balance in patients presenting for treatment for lumbar degeneration by measuring sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL), and sagittal vertical axis (SVA) on standing sagittal x-rays of the lumbar spine. Comparing sagittal balance among patients with a pathology of the lumbar area against control subjects to determine if they differ significantly from each other. Methods: This was done as a prospective cross-sectional study undertaken at Chris Hani Baragwanath Hospital's Department of Neurosurgery in Johannesburg, South Africa. A total of sixty participants comprising fifty patients with known lumbar degenerative pathologies (Group 1) and ten healthy volunteers (Group 2) were included. Standing lateral full spine radiographs were taken for all participants, while PACS software was used to measure parameters related to sagittal balance. Data analysis included logistic Page of4 68 regression, chi-square, independent t-tests with p<0.05 being considered statistically significant. Results: The findings pertaining to the study’s variables indicated significant results regarding sagittal balance parameters.Pelvic tilt emerged as one crucial predictor of sagittal balance where higher PT values were significantly associated with an imbalanced sagittally profile (p=0.0023). Group 1 had mean PT = 23.9° compared to the mean of 11.3° in Group 2. In addition, thoracic kyphosis (TK) was significantly higher in patients with lumbar degenerative disease compared to healthy subjects (p=0.03), though it failed to significantly differentiate balanced from unbalanced profiles within the group of patients. Other parameters including pelvic incidence, sacral slope and lumbar lordosis exhibited no statistically significant differences between the two groups. Multivariate analysis demonstrated a significant overall difference in sagittal balance parameters between the groups (p=0.0289). Conclusion: The study has established that there are several factors to be taken into consideration for assessing and managing patients with lumbar degenerative diseases, and this can be a complex task. Pelvic tilt and thoracic kyphosis are compensatory mechanisms which impact sagittal balance greatly. Findings imply the need for comprehensive and individualized assessment of patients having LDD. Clinicians must consider multiple parameters while ensuring successful diagnosis and treatment planning. Further research is required to address these limitations, like larger sample sizes and dynamic assessments amongst others, so as to gain deeper insights into the intricate relationship between sagittal balance parameters and lumbar degenerative diseases.