Background: Degenerative spine conditions are the most common cause of spinal cord injury in the elderly population and comprise degenerative disc disease, cervical spondylotic myelopathy, ossification, and hypertrophy of the spinal ligaments, which may result in cervical spinal canal stenosis. Dutch neurosurgeons working in Curaçao noticed a high incidence and more severe cases of cervical spinal canal stenosis (CSCS) compared to their practices in the Netherlands. Osseous narrowing of the spinal canal due to ossification of the flaval- and posterior longitudinal ligaments was also more frequently observed.
Objective: To assess the incidence and severity of CSCS, based on morphologic parameters of the spinal canal and spinal cord, in the population of Curaçao compared to literature. Additionally, the prevalence of ossification of the posterior longitudinal and flavum ligaments (OPLL/OLF) was calculated and compared to literature reports.
Methods: Retrospective descriptive study analyzing data gathered from patients with known symptomatic CSCS, as confirmed on MRI scans from 01-2017 until 12-2020. The anterio-posterior diameter, cross-sectional surface area of the spinal canal, spinal cord, and dural sac were measured at mid-vertebral and intervertebral disc levels on MRI scans. The degree of OPLL and OLF were assessed on CT scans. Additionally, the annual observed incidence of CSCS was calculated.
Results: 278 patients were recruited.The annual incidence of CSCS was 55.9/100 000 people, which is 13-fold higher compared to literature findings. In men and women, the narrowest spinal canal was at C4-C5, with a mean diameter of 8.2mm and 8.5mm, respectively. The mean diameter at non-stenotic levels was 12.9mm at mid-vertebral level and 11.8mm at disc level, consistently lower than the internationally accepted 13mm threshold defining normality versus stenosis. The prevalence of OPLL and OLF was 4.7%(n=13) and 2.5%(n=7), respectively, which is comparable with reports from Asia but higher compared to USA cohorts.
Conclusion: The annual incidence of CSCS in the population of Curaçao is substantially higher compared to reports originating from North America and Western Europe. Remarkably, the diameter of the non-stenotic cervical levels was consistently below 13mm, and the prevalence of OPLL/OLF findings was similar to Asians but higher compared to Caucasians. This study warrants future studies in cervical spinal stenosis to take the differences in morphologic parameters into account when selecting patients from various racial origins.