Age-Adjusted Alignment Goals Have the Potential to Reduce PJK

Area of Science:

• Spine surgery
• Adult spinal deformity (ASD)
• Biomechanical analysis

Background:

• Age-specific alignment targets are crucial in adult spinal deformity (ASD) surgery.
• Proximal junctional kyphosis (PJK) is a known complication, influenced by age and malalignment.
• Previous studies have not assessed the age-specific impact of alignment on PJK.

Purpose of the Study:

• To investigate proximal junctional kyphosis (PJK) in relation to age-adjusted surgical correction goals.
• To analyze the incidence of PJK across different age groups undergoing spinal fusion.
• To determine if overcorrection relative to age-specific targets influences PJK development.

Main Methods:

• Retrospective cohort study of 679 adult spinal deformity patients fused to the pelvis.
• Patients stratified into young adults (<40), middle-aged (40-65), and elderly (>65).
• Comparison of 1-year postoperative alignments and offsets from age-specific targets using ANOVA.

Main Results:

• Overall PJK incidence was 45.1%, increasing with age (YA 17.9%, MA 43.8%, ED 50.2%).
• PJK patients, particularly in older groups, showed overcorrection compared to age-specific alignment goals (e.g., PI-LL and SVA offsets).
• Age-specific alignment targets were significantly associated with PJK development, especially in elderly patients.

Conclusions:

• Patients who developed PJK were often overcorrected relative to age-adjusted alignment goals.
• Elderly patients face independent PJK risk factors, complicating prevention.
• Individualized surgical alignment optimization, incorporating age-specific targets, is essential for improving outcomes and preventing PJK.