Scoliosis risk factors and outcomes in children with dysplastic spondylolisthesis undergoing surgical reduction and fixation

Abstract

Purpose: To explore scoliosis risk factors and outcomes in children with dysplastic spondylolisthesis undergoing surgical reduction and internal fixation. Methods: We retrospectively analyzed 56 children with dysplastic spondylolisthesis who underwent surgical reduction and internal fixation. Patients were grouped according to presence of scoliosis before surgery. Radiographic parameters measured before surgery included pelvic incidence, pelvic tilt, sacral slope, coronal Cobb angle, slip percentage, Dubousset’s lumbosacral angle, lumbar lordosis, sagittal vertical axis, and Spinal Deformity Study Group index. Groups were compared using logistic regression. Receiver operating characteristic analysis was performed to determine the optimal Spinal Deformity Study Group index cut-off value. All patients were followed up for at least 2 years. Results: The scoliosis group comprises 36 patients (mean age: 9.6 ± 2.7 years), while the no scoliosis group comprises 20 (mean age: 9.1 ± 2.4 years). Slip percentage and Spinal Deformity Study Group index were significantly higher in the scoliosis group (p < 0.01). Sacral slope and pelvic incidence were lower in the scoliosis group (p < 0.05). Univariate logistic regression analysis showed that slip percentage, Spinal Deformity Study Group index, pelvic incidence, and sacral slope were significantly associated with scoliosis. In the multivariate logistic regression analysis, only Spinal Deformity Study Group index was an independent risk factor for scoliosis. The optimal cut-off value for Spinal Deformity Study Group index was 0.288. Mean Cobb angle decreased from 20.3° ± 8.8° before surgery to 8.5° ± 8.9° at last follow-up; the mean scoliosis correction rate was 59.3%. Conclusion: Severe S1 dysplasia and high slip percentage may be risk factors for developing scoliosis in patients with dysplastic spondylolisthesis. Scoliosis resolved spontaneously after spondylolisthesis reduction and fixation in most patients. Level of evidence 3.