Posterior Ligamentous Augmentation is Associated With Reduced Rates of Proximal Junctional Kyphosis and Failure in Adult Spinal Deformity Surgery: A Systematic Review and Meta-Analysis of 1333 Patients.

Abstract

Systematic review and meta-analysis. To evaluate the impact of posterior ligamentous augmentation (PLA) on proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) in adult spinal deformity (ASD) surgery. Adult spinal deformity (ASD) surgery is frequently complicated by PJK and PJF, with reported rates ranging from 17% to 61.7%. Techniques such as PLA, which involves spinous process or sublaminar tethering at the upper instrumented vertebra (UIV) +1 or +2, have been investigated as potential methods to mitigate these complications. A systematic literature review and meta-analysis was performed according to the PRISMA guidelines. Most studies defined PJK as an increase of ≥10° or ≥20° in the sagittal Cobb angle from UIV to UIV+2 compared with preoperative measurements. PJF was defined as PJK necessitating revision surgery. Eight comparative studies comprising 1333 patients (PLA: 579; no PLA: 754) were included. The mean age ranged from 55 to 68.6 years across studies, with a mean follow-up period of 17.6 to 31.2 months. There were no significant differences between the PLA and no PLA groups in terms of age (MD: 2.53; 95% CI: -0.28 to 5.34, I2 : 64.8%), BMI (MD: 1.03; 95% CI: -0.87 to 2.93, I2 : 69%), or sagittal vertical axis (SVA) preoperatively (MD: 3.92; 95% CI: -1.90 to 9.75, I2 : 73.1%) and postoperatively (MD: -1.54; 95% CI: -4.10 to 1.01, I2 : 56.2%). However, the PLA group demonstrated significantly lower odds of developing PJK compared with the no PLA group (PLA: 25.8%; no PLA: 28.8%; OR: 0.54; 95% CI: 0.34-0.85, I2 : 37.4%). Furthermore, PLA was associated with significantly lower odds of PJF (PLA: 3.3%; no PLA: 12.3%; OR: 0.23; 95% CI: 0.12-0.47, I2 : 17.9%). PLA in ASD surgery is associated with reduced odds of developing PJK and PJF over a follow-up period of 17.6 to 31.2 months.