Ossification of the Posterior Longitudinal Ligament in a Southern Level One Trauma Center

Introduction: Ossification of the posterior longitudinal ligament (OPLL) occurs most frequently in the cervical spine and may place patients at higher risk for spinal cord injury after trauma. Though the pathogenesis remains poorly understood, OPLL has been poorly characterized outside Asian populations. We examined the prevalence and characteristics of cervical spine OPLL at our Southern, public, Level 1 Trauma and Advanced Comprehensive Stroke Center.

Methods: We incorporated a novel free-text search methodology to identify patients with computed tomography (CT) reports including “ossification/calcification of the posterior longitudinal ligament” who presented to our institution between August 2020 and January 2023. We collected demographic, clinical, and radiological parameters, and we classified patients into circumscribed, segmental, mixed, and continuous OPLL groups. We measured spinal stenosis for the mixed and continuous OPLL groups.

Results: Of 17091 total CT scans performed in the emergency department, 412 (2.4%, 95% confidence interval 2.1-2.7%) patients met inclusion criteria. 254 (61.7%) were male. 200 (48.5%) were African-American. 191 (46.4%) were Caucasian, 6 (1.5%) were Asian, and 4 (1.0%) were Hispanic. There were 84 (20.4%) circumscribed, 200 (48.5%) segmental, 37 (9.0%) mixed, and 91 (22.1%) continuous OPLL patients. Mean minimal spinal canal diameter was 13.7mm with 7.3mm left for the spinal cord once accounting for OPLL (53.3% stenosis) for the mixed group and 13.5mm with 8.1mm left for the spinal cord (60.6% stenosis) for the continuous OPLL group.

Conclusion : We report prevalence of OPLL in a large, Southern, rural cohort, using a novel, nonselective methodology. To our knowledge, this prevalence has not been reported previously in non-Asian populations. Further investigation is needed to determine any novel associated genetic or environmental risk factors for OPLL due to the implications of a significant reported number of asymptomatic patients.