Abstract
Introduction: Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) frequently develop as major complications after surgery for adult spinal deformities (ASD) with long-segment posterior spinal fusion. Despite the various potentially useful techniques reported previously, complications remain difficult to treat. This study adds to our knowledge of the effects of two-level prophylactic balloon-assisted vertebroplasty (BVP) on the incidence of PJK/PJF.
Methods: Twenty-seven patients with adult spinal deformities underwent a combination of lateral lumbar interbody fusion (LLIF), long-segment posterior spinal fusion from the low thoracic spine to the pelvis, and two-level BVP. They were followed up for a minimum 3-year postoperatively. All patients had BVP at the uppermost instrumented vertebra (UIV) and the supra-adjacent vertebra (UIV+1).
Results: Lumbar lordosis (LL), pelvic incidence minus LL (PI-LL), pelvic tilt (PT), the sagittal vertical axis (SVA), and Cobb angle significantly improved after surgery but tended to worsen over time. The cumulative incidences of PJK and PJF after surgery reached 25.9% and 11.1% after 1 year, 40.7% and 18.5% after 2 years, and 48.1% and 22.2% after 3 years.
Five (18.5%) patients required emergency surgery with proximal extension of the fusion for impaired spinal cord function caused by PJF between the UIV and UIV+1 within 2 years after the initial surgery.
Conclusions: Two-level prophylactic BVP did not prevent PJK and PJF but rather carried the risk of acute spinal cord impairment as a trade-off between rigid UIV fixation and increased mechanical stress at the proximal junction.
