The Use of Hooks in Upper Instrumented Vertebra to Prevent Proximal Junctional Complications: A Systematic Review and Meta-Analysis

Proximal junctional kyphosis (PJK) and failure (PJF) affect up to 39% of adult spinal deformity (ASD) patients within two years postoperatively, often necessitating revision surgery. Pedicle screws create abrupt stiffness transition at the upper instrumented vertebra (UIV), while hooks may provide a “softer landing.” Comparative evidence has been limited. We performed a PRISMA-guided systematic review and meta-analysis of PubMed, Cochrane, and SpringerLink (2000–2025) comparing hook versus pedicle screw fixation at the UIV in ASD. Primary outcomes were PJK and PJF incidence. Pooled risk ratios (RR) were calculated using random-effects models. Five studies (1,131 patients) met inclusion. For PJF (3 studies, n=948), hooks significantly reduced incidence (6.9% vs. 25.3%; RR 0.32, 95% CI 0.17–0.59, p<0.001)—a 68% relative risk reduction. For PJK (2 studies, n=183), a trend favored hooks (22.0% vs. 29.1%; RR 0.76, 95% CI 0.46–1.25, p=0.28). Combined analysis showed significant overall protection (RR 0.50, 95% CI 0.31–0.82, p<0.05). Heterogeneity was low (I 2 =0%) with no publication bias. Transverse process hooks at the UIV substantially reduce PJF requiring revision, with a 68% risk reduction. Surgeons should consider hooks for high-risk patients (age >65, osteoporosis, poor paraspinal muscle quality) using hybrid constructs. Residual complications (6.9%) confirm no single technique suffices; optimal prevention requires patient-specific risk stratification. We conclude that hooks are a simple, low-cost adjunct for junctional protection in selected ASD patients.