Search

Purpose: To investigate the effectiveness of surgical reduction in high-grade spondylolisthesis in maintaining or restoring a normal pelvic balance, as related to the QoL., Methods: It is a retrospective analysis of prospectively collected data of 60 patients (17 males, 43 females) aged 15 ± 3.1 years who underwent surgery for high-grade spondylolisthesis and were followed for a minimum of 2 years after surgery. Patients with a residual high-grade slip following surgery were referred to the postoperative high-grade (PHG) group, while patients with a residual low-grade slip were referred to the postoperative low-grade (PLG) group. Pelvic balance was assessed from pelvic tilt and sacral slope, in order to identify patients with a balanced pelvis or unbalanced pelvis. The SRS-22 questionnaire was completed before surgery and at last follow-up., Results: Postoperatively, there were 36 patients with a balanced pelvis and 24 patients with an unbalanced pelvis. The improvement in QoL was better in patients with a postoperative balanced pelvis. There were 14 patients in the PHG group and 46 patients in the PLG group. Four of seven patients (57%) in the PHG group and 21 of 26 patients (81%) in the PLG group with a preoperative balanced pelvis maintained a balanced pelvis postoperatively (P = 0.1). None of the patients in the PHG group and 11 of 20 patients (55%) in the PLG group improved from an unbalanced to a balanced pelvis postoperatively (P < 0.05)., Conclusions: Surgical reduction in high- to low-grade slip is more effective in maintaining and restoring a normal pelvic balance postoperatively. These slides can be retrieved under Electronic Supplementary Material.

Study Design: Retrospective review of a radiographic database of high-grade spondylolisthesis patients in comparison with asymptomatic controls., Objective: To analyze the sagittal spinopelvic alignment in high-grade spondylolisthesis patients and identify subgroups that may require reduction to restore sagittal balance., Summary of Background Data: High-grade spondylolisthesis is associated with an abnormally high pelvic incidence (PI); however, the spatial orientation of the pelvis, determined by sacral slope (SS) and pelvic tilt (PT), is not known. We hypothesized that sagittal spinal alignment would vary with the pelvic orientation., Methods: Digitized sagittal radiographs of 133 high-grade spondylolisthesis patients (mean age, 17 years) were measured to determined sagittal alignment. K-means cluster analysis identified 2 groups based on the PT and SS, which were compared by paired t test. Comparisons were made to asymptomatic controls matched for PI., Results: High-grade spondylolisthesis patients had a mean PI of 78.9 degrees +/- 12.1 degrees . Cluster analysis identified a retroverted, unbalanced pelvis group with high PT (36.5 degrees +/- 8.0 degrees )/low SS (40.3 degrees +/- 9.0 degrees ) and a balanced pelvic group with low PT (mean 21.3 degrees +/- 8.2 degrees )/high SS (59.9 degrees +/- 11.2 degrees ). The retroverted pelvis group had significantly greater L5 incidence and lumbosacral angle with less thoracic kyphosis than the balanced pelvic group. A total of 83% of controls had a "balanced pelvis" based on the categorization by SS and PT., Conclusion: Analysis of sagittal alignment of high-grade spondylolisthesis patients revealed distinct groups termed "balanced" and "unbalanced" pelvis. The PT and SS were similar in controls and balanced pelvis patients. Unbalanced pelvis patients had a sagittal spinal alignment that differed from the balanced pelvis and control groups. Treatment strategies for high-grade spondylolisthesis should reflect the different mechanical strain on the spinopelvic junction in each group; reduction techniques might be considered in patients with an unbalanced pelvis high-grade spondylolisthesis.