Characteristics of Spinopelvic Sagittal Alignment in Lumbar Degenerative Disease.

BACKGROUND: Normal sagittal alignment shows a range of variations and normal values. This study compared sagittal vertebral alignment in patients with different degenerative lumbar diseases. METHODS: This cross-sectional study evaluated 300 patients who were enrolled between June 2016 and June 2017. Of these patients, 213 met the study criteria and were included. RESULTS: Of the 213 patients, 66 were men (31%) and 147 were women (68.2%). The mean age was 62.7 years. Diagnoses included degenerative spondylolisthesis in 116 patients (52.7%), lumbar disk degeneration in 76 patients (34.5%), lumbar spinal stenosis in 19 patients (8.6%), and lytic spondylolisthesis in 7 patients (3.2%). The most frequent Roussouly type of sagittal alignment was type 3 (33.6%), followed by type 4 (25.9%). No significant correlation was associated with Roussouly type of sagittal alignment and lumbar degenerative disease. Median sagittal vertebral alignment parameters in the series were as follows: pelvic incidence (PI), 60.55 degrees +/- 15.62 degrees; sacral slope, 39.09 degrees +/- 12.48 degrees; pelvic tilt, 20.92 degrees +/- 8.99 degrees; lumbar lordosis, 33.15 degrees +/- 18.49 degrees; and sagittal balance, 19.64 +/- 55.27 mm. One hundred sixteen patients with degenerative spondylolisthesis had significant greater PI than those with other diagnoses (61.56 degrees vs. 58.3 degrees, respectively; P = 0.005), and patients with lumbar spinal stenosis had significantly lower PI than those with other diagnoses (55.89 degrees vs. 60.44 degrees, respectively; P = 0.005). CONCLUSIONS: Pelvic incidence may play a predisposing role in the pathogenesis of lumbar degenerative disease. Patients with degenerative spondylolisthesis have greater pelvic incidence with increased lumbar lordosis. In contrast, patients with spinal stenosis have lower pelvic incidence with flatter lumbar lordosis.