A new classification system for degenerative spondylolisthesis of the lumbar spine

There is no consensus for a comprehensive analysis of degenerative spondylolisthesis of the lumbar spine (DSLS). A new classification system for DSLS based on sagittal alignment was proposed. Its clinical relevance was explored. Health-related quality-of-life scales (HRQOLs) and clinical parameters were collected: SF-12, ODI, and low back and leg pain visual analog scales (BP-VAS, LP-VAS). Radiographic analysis included Meyerding grading and sagittal parameters: segmental lordosis (SL), L1-S1 lumbar lordosis (LL), T1-T12 thoracic kyphosis (TK), pelvic incidence (PI), pelvic tilt (PT), and sagittal vertical axis (SVA). Patients were classified according to three main types-1A: preserved LL and SL; 1B: preserved LL and reduced SL (<= 5A degrees); 2A: PI-LL >= 10A degrees without pelvic compensation (PT < 25A degrees); 2B: PI-LL >= 10A degrees with pelvic compensation (PT >= 25A degrees); type 3: global sagittal malalignment (SVA >= 40 mm). 166 patients (119 F: 47 M) suffering from DSLS were included. Mean age was 67.1 +/- 11 years. DSLS demographics were, respectively: type 1A: 73 patients, type 1B: 3, type 2A: 8, type 2B: 22, and type 3: 60. Meyerding grading was: grade 1 (n = 124); grade 2 (n = 24). Affected levels were: L4-L5 (n = 121), L3-L4 (n = 34), L2-L3 (n = 6), and L5-S1 (n = 5). Mean sagittal parameter values were: PI: 59.3A degrees A +/- 11.9A degrees; PT: 24.3A degrees A +/- 7.6A degrees; SVA: 29.1 +/- 42.2 mm; SL: 18.2A degrees A +/- 8.1A degrees. DSLS types were correlated with age, ODI and SF-12 PCS (rho = 0.34, p < 0.05; rho = 0.33, p < 0.05; rho = -0.20, and p = 0.01, respectively). This classification was consistent with age and HRQOLs and could be a preoperative assessment tool. Its therapeutic impact has yet to be validated. Level of evidence 4.