Radiologic risk factors associated with development of myelopathy in patients with ossification of the posterior longitudinal ligament of the cervical spine

• Published in: Clinical neurology and neurosurgery Vol. 227; p. 107668
• Main Authors: Kwon, Woo-Keun, Ham, Chang Hwa, Moon, Hong Joo, Kim, Joo Han, Park, Youn-Kwan
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-04-2023; Elsevier Limited
• Subjects: Canals (anatomy); Central nervous system diseases; Cervical spine; Cervical Vertebrae - diagnostic imaging; Classification; Clinical significance; Coexistence; Comorbidity; Degeneration; Degenerative disc disease; Humans; Intervertebral discs; Ligaments; Longitudinal Ligaments; Multivariate analysis; Myelopathy; Neurology; OPLL; Ossification; Ossification of Posterior Longitudinal Ligament - complications; Ossification of Posterior Longitudinal Ligament - diagnostic imaging; Osteogenesis; Patients; Radiologic factor; Regression analysis; Retrospective Studies; Risk Factors; Spinal cord; Spinal Cord Diseases - complications; Spinal Cord Diseases - etiology; Spine (cervical); Statistical analysis; Treatment Outcome; Radiologic factor; Myelopathy; OPLL; Cervical spine
• ISSN: 0303-8467; 1872-6968
• DOI: 10.1016/j.clineuro.2023.107668

Retrospective Cohort Study
Myelopathy following ossification of the posterior longitudinal ligament (OPLL) is one of the devastating clinical features in these patients, while we still know little about which factors are associated with development of myelopathy. We evaluated the difference of radiologic measurements between OPLL patients with or without myelopathy and searched for the clinical significance with emphasis on the impact of dynamic motion.
305 patients diagnosed of OPLL were enrolled for retrospective review. They were divided into two groups according to the coexistence of radiographic evidence of myelopathy. Demographic data as well as radiologic measures including the presence of disc degeneration (DD), anterior-posterior diameter (APD) of central canal, canal compromise (CC) ratio, global and segmental range of motion (gROM and sROM), OPLL type (morphologic classification) and K-line were collected.
APD (odds ratio (OR); 0.411), CC ratio (OR; 1.100) and sROM (OR; 1.371) were significantly associated with the presence of myelopathy in the multivariate analysis. While the statistically significant factors were same in OPLLs with CC larger than 50%, presence of DD (OR; 4.509) and sROM (OR; 1.295) were significantly associated with myelopathy but not the CC itself in OPLLs with CC smaller than 50%.
We discovered that the APD, CC ratio and sROM had significant association with development of myelopathy in OPLLs. And the presence of dynamic factors had significant association with myelopathy in OPLLs with smaller CC ratios. This observation and its clinical significance on development of myelopathy might enhance our understanding of OPLL.
•Static measures as the diameter of central canal, or canal compromise ratio are related with myelopathy in cervical OPLL.•Myelopathy in OPLLs with large CC ratio (50% or more) are associated with these static factors.•In OPLLs with smaller CC ratio, dynamic factors such as sROM and coexisting disc degeneration contribute to myelopathy.•This study might enhance our understanding of myelopathy in OPLLs.