Different Risk Factors between Bony and Ligamentous Proximal Junctional Failure in Patients Undergoing Thoracolumbar Fusion to Pelvis for Adult Spinal Deformity

Se-Jun Park; Jin-Sung Park; Dong-Ho Kang; Minwook Kang; Kyunghun Jung; Chong-Suh Lee

doi:10.1097/BRS.0000000000005151

Different Risk Factors between Bony and Ligamentous Proximal Junctional Failure in Patients Undergoing Thoracolumbar Fusion to Pelvis for Adult Spinal Deformity

Spine (Phila Pa 1976). 2024 Sep 4. doi: 10.1097/BRS.0000000000005151. Online ahead of print.

Authors

Se-Jun Park¹, Jin-Sung Park¹, Dong-Ho Kang¹, Minwook Kang¹, Kyunghun Jung¹, Chong-Suh Lee²

Affiliations

¹ Department of Orthopedic Surgery, Spine Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
² Department of Orthopedic Surgery, Haeundae Bumin Hospital, Busan, South Korea.

PMID: 39231736
DOI: 10.1097/BRS.0000000000005151

Abstract

Study design: Retrospective study.

Objective: To analyze the risk factors for bony proximal junctional failure (B-PJF) and ligamentous PJF (L-PJF) separately after adult spinal deformity (ASD) surgery.

Summary of background data: Despite numerous studies about the risk factors of PJF, it remains unclear whether same risk factors can be applied to both B-PJF and L-PJF.

Methods: Patients who underwent corrective surgery from low thoracic level (T9-T12) to pelvis with minimum follow-up duration of two years were included in this study. Patients with PJF were divided into two groups according to the involvement of bony structure: B-PJF and L-PJF. The control group was created using patients who did not develop PJF for ≥2 years postoperatively (no-PJF group). Risk factors were analyzed by comparing various clinical and radiographic parameters between no PJF versus B-PJF group and between no PJF versus L-PJF groups.

Results: The final study cohort comprised 240 patients. The mean age was 68.7 years, and there were 205 women (85.4%). On average, 8.1 levels were fused. PJF developed in 103 patients, with 70 (68.0%) in the B-PJF group and 33 (32.0%) in the L-PJF group. Stepwise logistic regression analyses revealed that older age (odds ratio [OR]=1.088), higher body mass index (BMI) (OR=1.161), osteoporosis (OR=3.293), greater postoperative lumbar distribution index (OR=1.032), and overcorrection relative to the age-adjusted pelvic incidence - lumbar lordosis (OR=3.964) were significant risk factors for B-PJF. Meanwhile, no use of transverse process (TP) hook was the single risk factor for L-PJF (OR=4.724).

Conclusions: Understanding the difference in risk factors between B-PJF and L-PJF will facilitate the optimization of surgical outcome for patients with ASD. Appropriate correction of sagittal malalignment along with use of TP hook is advisable to mitigate both B-PJF and L-PJF development.