Prevalence of “Congenital Lumbar Spinal Stenosis” in Patients with Chronic Low Back Pain in Mombasa

Abstract

Background: Chronic low back pain is one of the commonest maladies of man. There are multiple causes of chronic low back pain that will include degenerative, inflammatory and mechanical causes. Developmental lumbar spinal stenosis is known to cause symptoms of axial back pain with or without leg pain in the young adult. These symptoms become severer when patients with developmental stenosis acquire degenerative changes as the severity of theca sac and foramina compression increases. We hypothesized that developmental lumbar spinal stenosis is a major predisposing factor for chronic low back pain in adult population.
Objective: The purpose of this study was to evaluate the prevalence of developmental lumbar spinal stenosis in a group of individuals suffering from chronic low back pain. This prevalence was compared with another group of asymptomatic individuals (without low back pain). Both Computed Tomography (CT)and Magnetic Resonance Imaging (MRI) images were used for this analysis.
Design: This was a prospective, case-control, radiographic study.
Subjects: Radiological materials from 118 individuals undergoing MRI scans for chronic low back pain with or without leg pain were analyzed to obtain the AP diameters of the lumbar vertebral body and vertebral canals at L4 and L5 levels. Ninety six patients were enrolled in this study. Abdominal CT scans of 96 patients without back pain were obtained from radiological archives for use as controls.
Methods: Using simple statistical methods the association between developmental lumbar spinal stenosis and chronic low back pain was examined.
Results: In the study group, 26% of the participants had canal stenosis (AP diameter <12mm) at the distal lumbar canal compared to 8% in the control group; 38% had moderate sized canal (12-14mm) in the study group (31% in control) while only 36% had a normal canal (66% in control group). The differences were found to be statistically significant (95% CI 0.4-1 P=0.0000023). In this study 64% of the patients had a canal diameter below the mean. The presence of a narrow canal is prevalent in these patients with chronic low back pain (Odds ratio 0.3). There was weak correlation between size of the body and size of the canal (Pearson’s r = 0.4).
Conclusion: There is significant association between developmental distal lumbar canal stenosis and chronic low back pain in adults.