Prevalence and Association Factors of Posterior Longitudinal Ligament in Patients with Spondyloarthropathies

Objective: To investigate prevalence of ossification of posterior longitudinal ligament (OPLL) in Korean patients with Spondyloarthropathies (SpA), and the associations between OPLL and clinical, radiologic findings of SpA. Method: A cross-sectional radiological review was performed in patients diagnosed with SpA from 2000 to 2007. Each of two physiatrists and musculoskeletal radiologists screened the cervical (lateral) and pelvis (anterior-posterior) radiographs of these patients separately, then confirmed presence of OPLL. Bath ankylosing spondylitis radiology index (BASRI) of the cervical spine and grade of sacroiliitis were also measured. A review of the medical records and laboratory findings was conducted to investigate the association between the clinical, laboratory findings and the OPLL. Results: Among 172 patients with SpA, OPLL was found in 16 patients (9.3%; 95% CI 5.0, 13.6). There were significant associations between OPLL and old age (p=0.043), symptoms and signs of myeloradiculopathy (p=0.030), and diabetes mellitus (DM) (p=0.022). Conclusion: The prevalence of OPLL in Korean patients with SpA is 9.3%. OPLL in patients with SpA is associated with old age, symptoms and signs of myeloradiculopathy, and diabetes. However, no factors specific characteristics of SpA were associated with OPLL.