European Spine Journal - 2026-07-13 - Journal Article
Whole-spine CT predictors of lumbar surgery in patients with ossification of the posterior longitudinal ligament.
Koike Y, Endo T, Shimamura Y, Kanayama M, Fujita R, Hasegawa Y, Fukada S, Takahata M, Kadoya K, Sudo H, Yamada K, Terkawi MA, Xue H, Ishii M, Iwasaki N
Topics
Key Takeaway
In OPLL patients, lumbar OLF (OR 6.49) and lumbar IVD gas (OR 5.75) are independent CT predictors of requiring lumbar surgery, with 39.3% of the cohort ultimately undergoing lumbar intervention.
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Summary
This study asked which whole-spine CT findings predict lumbar surgery in OPLL patients by retrospectively comparing 70 surgical and 108 non-surgical patients across imaging parameters. Multivariable logistic regression identified lumbar OLF (OR 6.49, 95% CI 2.60–16.25) and lumbar IVD gas (OR 5.75, 95% CI 2.37–13.97) as independent predictors. The surgical cohort also showed higher prevalence of thoracolumbar ankylosis and a diffuse whole-spine ossification phenotype, with coexisting OPLL and OLF at the same level correlating with younger surgical age and greater neurological severity.
Key Limitation
The absence of standardized surgical thresholds means lumbar surgery indication varied by surgeon and institution across a 16-year span, limiting reproducibility of the risk model.
Original Abstract
PURPOSE
Patients with ossification of the posterior longitudinal ligament (OPLL) may require lumbar surgery due to ossified lesions and degenerative changes. However, risk stratification for lumbar intervention remains underexplored. We aimed to identify predictors of lumbar surgery in patients with OPLL.
METHODS
We retrospectively analyzed 178 OPLL patients who underwent whole-spine computed tomography (CT) (2007-2023). Patients were classified according to whether they underwent lumbar surgery. CT obtained prior to lumbar surgery or during conservative follow-up was reviewed. Imaging parameters, including ossification distribution and degenerative changes, were compared between groups and analyzed using multivariable logistic regression to identify independent predictors.
RESULTS
Lumbar surgery was performed in 70 (39.3%) patients. The surgery group exhibited higher body mass index and greater prevalence of thoracolumbar ankylosis, thoracic and lumbar OPLL, lumbar ossification of the ligamentum flavum (OLF), and intervertebral disc (IVD) gas. Multivariable analysis identified lumbar OLF (OR, 6.49; 95% CI, 2.60-16.25) and lumbar IVD gas (OR, 5.75; 95% CI, 2.37-13.97) as independent risk factors. Coexisting OPLL and OLF at the same level was associated with younger surgical age and greater neurological severity.
CONCLUSIONS
Using whole-spine CT, we demonstrated that patients requiring lumbar surgery frequently exhibited a diffuse whole-spine ossification phenotype, characterized by thoracolumbar OPLL and ankylosis. Lumbar OLF and IVD gas were identified as independent risk factors; notably, lumbar OLF reflects this generalized ossification tendency, whereas disc gas indicates mechanical stress and degeneration. These findings support whole-spine CT-based risk stratification and longitudinal monitoring in patients with OPLL.