Progression of Ossification of Posterior Longitudinal Ligament After Anterior Cervical Discectomy and Fusion in Military Patients Exposed to Minor Trauma

• Published in: Korean journal of neurotrauma 2022-10, Vol.18 (2), p.254-267
• Main Authors: Koo, Jungmyung, Hwang, SungHwan, Yoon, Sang Hoon, Shin, Hyung Jin, Cho, Byung-Kyu
• Format: Article
• Language: English
• Subjects: Current Issue
• ISSN: 2234-8999; 2288-2243
• DOI: 10.13004/kjnt.2022.18.e55

Ossification of the posterior longitudinal ligament (OPLL) can progress even after cervical spine surgery and may cause neurological injury as a result of minor trauma. The purpose of this study was to investigate the preventive factors associated with OPLL progression after anterior cervical discectomy and fusion (ACDF), a procedure commonly performed in clinical practice. We retrospectively investigated 295 male soldiers who underwent ACDF surgery between 2012 and 2017. Patients who were followed up for >12 months using dynamic radiography and computed tomography (CT) were included in the study. Radiological parameters investigated included OPLL progression, C2-C7 angles on dynamic radiography, segmental angles, C2-C7 cervical sagittal vertical axis (C2-C7 SVA), and the T1 slope. These parameters were measured preoperatively and 1 year postoperatively. A total of 49 patients were enrolled, and 10 patients were confirmed to have OPLL progression. Comparison between the OPLL progression and non-progression groups showed no statistically significant differences in pre- and postoperative cervical range of motion. However, statistically significant differences were observed in the postoperative neutral C2-C7 angle (progression -3.9°±6.4° vs. non-progression -13.4°±7.9°, =0.001) and the SVA change (progression 5.8±7.9 mm vs. non-progression -3.7±6.3 mm, =0.00). The cutoff values were -8.01° for the postoperative neutral C2-C7 angle and 1.4 mm for SVA changes. Increased SVA (>1.4 mm) and a small postoperative neutral C2-C7 angle (>-8.01°) 1 year after ACDF were associated with OPLL progression. It is important to be mindful of these factors during follow-up after ACDF, because additional surgical treatment may be necessary for OPLL progression due to neurological injury caused by minor trauma.