Prevalence and Consequences of the Proximal Junctional Kyphosis After Spinal Deformity Surgery: A Meta-Analysis

The aim of this study was to estimate the prevalence and patient outcomes of proximal junctional kyphosis (PJK) in pediatric patients and adolescents who received surgical interventions for the treatment of a spinal deformity.Literature was searched in electronic databases, and studies were selected by following précised eligibility criteria. Percent prevalence values of the PJK in individual studies were pooled to achieve a weighted effect size under the random effects model. Subgroup and meta-regression analyses were performed to appraise the factors affecting PJK prevalence.Twenty-six studies (2024 patients) were included in this meta-analysis. Average age of the patients was 13.8 ± 2.75 years of which 32 ± 20 % were males. Average follow-up was 51.6 ± 38.8 (range 17 ± 13 to 218 ± 60) months. Overall, the percent prevalence of PJK (95% confidence interval) was 11.02 (10.5, 11.5) %; P < 0.00001 which was inversely associated with age (meta-regression coefficient: -1.607 [-2.86, -0.36]; 0.014). Revision surgery rate in the patients with PJK was 10%. The prevalence of PJK was positively associated with the proximal junctional angle at last follow-up (coefficient: 2.248; P = 0.012) and the change in the proximal junctional angle from surgery to last follow-up (coefficient: 2.139; P = 0.014) but not with preoperative proximal junctional angle.The prevalence of PJK in the children and adolescent patients is 11%. About 10% of those affected require revision surgery.