Quantification of Risk Factors for Cervical Ossification of the Posterior Longitudinal Ligament in Korean Populations

Study Design. Case-control study. Objective. To quantify risk factors for cervical ossification of the posterior longitudinal ligament (OPLL) using a large nationwide cohort in Korea, a country with a high prevalence of OPLL. Summary of Background Data. OPLL is a pathological calcification of the posterior longitudinal ligament of the spine. OPLL progression can cause spinal cord injury that results in disability. Considering neurologic deficits and disability caused by OPLL, identifying OPLL risk factors for early prediction have important health benefits. Methods. The nationwide population-based matched cohort study was conducted using the Korean National Health Insurance Service cohort data. We selected patients with a primary diagnosis of OPLL involving cervical lesion (International Classification of Diseases-10 code: M48.82, M48.83). A matched cohort without cervical OPLL was enrolled by randomly matching patients by sex, age, year of diagnosis, and residential area to the OPLL group with a ratio of 1:9. Logistic regression analyses were performed to identify risk associated with OPLL development using odds ratios (OR) and 95% confidence intervals (CI). Results. Comorbidities, such as hypertension (OR = 1.283, 95% CI 1.071–1.538), ischemic stroke (OR = 1.386, 95% CI 1.017–1.889), diabetes mellitus (OR = 1.331, 95% CI 1.098–1.615), hypothyroidism (OR = 1.562, 95% CI 1.165–2.094), and osteoporosis (OR = 1.456, 95% CI 1.151–1.842), were significantly associated with the prospective development of OPLL, with low predictive value. Conclusion. OPLL was significantly associated with comorbidities such as hypertension, ischemic stroke diabetes mellitus, hypothyroidism, and osteoporosis. Our findings can provide helpful information for OPLL prediction and offer important health benefits. Level of Evidence: 3