Evaluation of Radiological Parameters in Pre-operative and Post-operative Lumbar Spondylolisthesis

Abstract Aim: The study aimed to evaluate radiological parameters in pre- and post-operative lumbar spondylolisthesis cases to assess the effectiveness of internal fixation and fusion surgeries in restoring spinal-pelvic alignment. Materials and Methods: This prospective observational cohort study was conducted at the Central Institute of Orthopedics, VMMC and Safdarjung Hospital, New Delhi, over 18 months. A total of 30 patients aged 25–60 years with lumbar spondylolisthesis were included. Pre-operative and 3-month post-operative X-rays were analyzed to measure pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and lumbar lordosis (LL). Data were statistically analyzed using paired t -tests or Wilcoxon tests, with significance set at P < 0.05. Results: The mean age of participants was 43.17 ± 9.74 years, with a female predominance (73.3%). Pre-operative mean PI was 61.93 ± 7.36, slightly decreasing post-operative to 60.43 ± 8.21 ( P = 0.23). PT significantly improved from 23.83 ± 5.63 to 19.17 ± 5.54 ( P < 0.001). SS increased significantly from 38.40 ± 6.43 to 41.40 ± 7.04 ( P < 0.01). LL also improved significantly from 47.90 ± 10.41 to 52.93 ± 9.16 ( P < 0.001). Changes in PT, SS, and LL demonstrated enhanced sagittal alignment post-surgery, while PI remained stable, highlighting its anatomical consistency. Conclusion: The study demonstrates that surgical intervention significantly improves spinal-pelvic alignment in lumbar spondylolisthesis patients. Restoring LL and achieving appropriate PT and SS are critical for maintaining sagittal balance, given the constancy of PI. Proper pre-operative evaluation of spinopelvic parameters can guide surgical planning to optimize post-operative outcomes.