Clinical Risk Factors for Thoracic Ossification of the Ligamentum Flavum: A Cross-Sectional Study Based on Spinal Thoracic Three-Dimensional Computerized Tomography

BACKGROUND: Inconsistent results of the clinical risk factors associated with thoracic ossification of the ligamentum flavum (TOLF) have been reported in limited previous studies. PURPOSE: This retrospective study aimed to investigate the potential risk factors for TOLF by a retrospective cross-sectional study, which may provide valuable experience for further clinical and pathophysiological research. METHODS: A total of 2247 asymptomatic participants, who underwent spinal thoracic three-dimensional computerized tomography (3D-CT) scans at our institution from January 2016 to December 2019, were enrolled in this study according to the screening criteria. Demographic information such as age, sex, height, weight, body mass index (BMI), smoking and drinking history, diastolic blood pressure (DBP), systolic blood pressure (SBP), and pulse pressure (PP) were recorded. Laboratory results included serum low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), triglyceride (TG), uric acid (UA), creatinine (Cr), calcium, and phosphorus. Participants were divided into TOLF group and non-TOLF group in accordance with the thoracic 3D-CT manifestation. RESULTS: TOLF was observed in 153 (6.81%) asymptomatic participants. Comparison of demographic data and laboratory examinations between the two groups showed that participants in the TOLF group were older, had a higher BMI, as well as higher levels of DBP. In addition, there was no significant difference in sex, drinking, tobacco use, SBP, TC, TG, PP, and levels of LDL-C, HDL-C, sUA, sCr, calcium, and phosphorus between the two groups. Furthermore, dichotomous logistic regression analyses revealed that age (OR = 1.018, p = 0.041) and BMI (OR = 1.090, p < 0.001) were risk factors for TOLF. CONCLUSION: Our study reveals that age and BMI are clinical risk factors for the development of TOLF, while age cannot be identified as an independent risk factor for female in subgroup analysis.