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Multilevel Oblique Lumbar Interbody Fusion in Degenerative Lumbar Disc Disease with Instability
Published on: July 25, 2025
Acute Disc Herniation at the Proximal Junctional Segment (UIV/UIV + 1) Following Long Segment Spinal Fusion With
Dana Saleh1, Ahmad Zayd Alkadri2, Sadegh Bagherzadeh3
1Department of Neurosurgery, Brain and Spine, University of South Florida, Morsani College of Medicine, Tampa, FL, USA danasaleh@usf.edu.
International Journal of Spine Surgery
|June 9, 2026
Summary
Prophylactic cement augmentation in spinal fusion can lead to acute disc herniation, causing rapid neurological decline. Surgeons should consider strategies to mitigate this risk by preserving gradual stiffness transitions.
Area of Science:
- Spine surgery
- Biomedical engineering
- Orthopedics
Background:
- Prophylactic cement augmentation at the uppermost instrumented vertebra (UIV) and UIV+1 is common in long-segment fusion for adult spinal deformity.
- This strategy aims to reduce proximal junctional failure but its effect on adjacent soft tissues, like the intervertebral disc, is unclear.
- Acute disc herniation (ADH) at the proximal junction is a rare but serious complication.
Purpose of the Study:
- To investigate the association between prophylactic cement augmentation and acute disc herniation (ADH) at the proximal junction after long-segment spinal fusion.
- To analyze radiographic parameters and clinical outcomes in patients who developed ADH compared to matched controls.
Main Methods:
- Retrospective cohort study of 173 patients undergoing long-segment posterior spinal fusion (≥5 levels) with UIV/UIV+1 cement augmentation.
- Nine patients who developed ADH were propensity score matched (1:3) with 27 controls.
- Radiographic parameters (Cobb angles, disc slope, disc height) at the UIV/UIV+1 junction were measured preoperatively and at diagnosis/follow-up.
Main Results:
- The ADH group showed significantly greater junctional deterioration, including increased UIV Cobb angle (+20.3° vs +1.2°), adjacent segment Cobb angle (+18.5° vs +1.7°), and decreased disc height (-3.5 mm vs -0.9 mm) compared to controls.
- ADH patients experienced acute neurological deterioration requiring urgent revision surgery.
- Smoking was more prevalent in the ADH group (P=0.03).
Conclusions:
- Acute disc herniation following cement augmentation is linked to significant junctional collapse and rapid neurological decline, suggesting a biomechanical failure due to overstiffening.
- Strategies preserving a gradual stiffness transition at the proximal junction may be necessary to reduce ADH risk.
- Spine surgeons must maintain a high suspicion for ADH in patients with new neurological symptoms post-fusion.
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