Predictors of the Need for Surgery in Cervical Ossification of the Posterior Longitudinal Ligament: A Retrospective Cohort Longitudinal Study Using a Claims-based Database.

Abstract

Retrospective cohort study. The aim of this study was to determine predictors associated with the needfor cervical ossification of the posterior longitudinal ligament (cOPLL) surgery amongindividuals with cOPLL. cOPLL is a spinal disorder caused by ectopic ossification of the posterior longitudinal ligament. However, factors associated with a higher rate of surgery to treat the neurological symptoms of cOPLL are poorly understood. This retrospective population-based cohort study using a commercial administrative claims database from JMDC Inc. (Tokyo, Japan) enrolled patients newly diagnosed with cOPLL from April 2005 to October 2020 and followed to April 2021. A total of 1506 cOPLL patients aged 18 years or older with no history of cervical spine surgery and with a record of metabolic profiles obtained at general health checkups were included. Cox proportional hazards regression models identified patient characteristics and comorbidities associated with cOPLL surgery. Of 1506 patients with cOPLL with a median of 1.8 years of follow-up after initial cOPLL diagnosis, 439 (29.2%) received cOPLL surgery. The 1-year cumulative incidence (95% CI) was 26.0% (23.7-28.2). In multivariable Cox proportional regression analysis, male (hazard ratio: 1.68; 95% CI: 1.26-2.24; P < 0.001) and obesity (body mass index: ≥25) (hazard ratio: 1.45; 95% CI: 1.10-1.89; P = 0.007) were associated with an increased risk of cOPLL surgery. In this large claims-based study of adults newly diagnosed with cOPLL, males and obesity were associated with a higher risk of cOPLL surgery. These findings may help clinicians to predict the future course of cOPLL in patients, although further research is needed to elucidate the biological role of these progression-associated factors.