Correlation of pelvic incidence and pelvic parameters in lumbar spondylolisthesis

BACKGROUND: Pelvic incidence (PI) and pelvic parameters (PP) regulate the sagittal alignment of the spine and the pelvis in normal populations. Correlation of PI even more so than PP with lumbar spondylolisthesis (LS) would be useful for surgical planning. METHODS: This study included 45 patients randomly selected with LS. They were divided into two groups; Group S had LS and Group C had low back pain due to other causes. All patients received lateral standing radiographs of the spine and pelvis. Based on these films, we measured the sacral slope, pelvic tilt, PI, and lumbar lordosis (LL). RESULTS: There were significant correlations between the PI and the sacral slope, pelvic tilt, and LL in Group S (P < 0.05). The majority of patients with LS presented with middle (60%) followed by high PIs (26.67%). Low PI was observed among just 13.33% patients with LS. CONCLUSION: Changes in spinopelvic parameters reflecting pelvic compensatory mechanisms differ depending on the extent of PI in patients with LS. In short, higher PI values correlated with more significant degrees of degenerative LS in Group S population.