Characteristics of spino-pelvic sagittal parameters in degenerative spondylolisthesis with kyphotic angulation and its clinical significance

English Keywords:Degenerative spondylolisthesis  Intervertebral space  Slip angle  Life quality

English Abstract:

  【Abstract】 Objectives: To investigate the impact of kyphotic angulation at the olisthesis level on spondylolisthesis related parameters and spino-pelvic sagittal parameters in degenerative lumbar spondylolisthesis(DLS) and its clinical significance. Methods: A consecutive cohort of 165 patients with L4/5 DLS(Meyerding grade Ⅰ or Ⅱ) between January 2013 and April 2016 was reviewed, including 28 males and 131 females, with an average age of 54.3±11.9 years(42-72 years). The patients were divided into two groups, including the kyphotic group and the non-kyphotic group, based on the angulation profile of the olisthesis level. Radiographic parameters including slip percentage, slip angle, anterior and posterior disc height, range of motion, pelvic incidence(PI), pelvic tilt, sacral slop, thoracic kyphosis, lumbar lordosis(LL) and sagittal vertical axis were measured. Oswestry disability index(ODI) and visual analogue scale/score(VAS) were completed to evaluate quality of life. Radiographic parameters and scores of life quality were compared between two groups. Results: Kyphotic slip was detected in 21(12.7%) of the 165 patients and the average age of the kyphotic group was significantly older than that of the non-kyphotic group(60.7±13.6 vs 53.4±11.9 years, P<0.05). The slip angle was significantly lower in the kyphotic group(-3.2°±2.4° vs 7.3°±4.3°, P<0.001), while slip percentage was higher in the kyphotic group compared to the non-kyphotic group[(22.4±4.4)% vs (18.9±3.8)%, P<0.001]. Compared to the non-kyphotic group, anterior disc height was significantly lower in the kyphotic group(P<0.001), while posterior disc height was higher in the kyphotic group(P<0.01). Translational motion and angular motion in the kyphotic group were significantly higher than those in the non-kyphotic group(P<0.001). Pelvic tilt and sagittal vertical axis in the kyphotic group were significantly higher than those in the non-kyphotic group(P<0.001), and LL and sacral slop were significantly lower in the kyphotic group than those in the non-kyphotic group(P<0.01). There was no difference in PI and thoracic kyphosis between the two groups(P>0.05), while PI-LL in the kyphotic group was significantly higher than that in the non-kyphotic group(P<0.001). The preoperative ODI, VAS back pain and leg pain scores in the kyphotic slip group were significantly higher than those in the non-kyphotic slip group(P<0.05). Conclusions: Kyphotic slip was observed in 12.7% of L4/5 DLS patients and had significant impact on the slip parameters and spino-pelvic sagittal parameters, which could lead to decline of life quality.