Demographic findings in patients with low back pain caused by lumbar spinal stenosis in Imam Khomeini Hospital of Tehran University (2003 - 2004)

Background: Low back pain (LBP) is one of the most common clinical problems with a high economic burden. Among the causes of LBP unresponsive to conservative management, is the lumbar spinal stenosis (LSS) that makes the lumbar spinal surgery inevitable. Objective: To determine the demographic findings in patients with low back pain caused by lumbar spinal stenosis based on their MRI performed in Imam Khomeini Hospital of Tehran University from June 2003 to September 2004. Methods: This was a cross-sectional descriptive study in which 200 patients with low back pain referred to imaging center of Imam Khomeini Hospital in Tehran were consecutively investigated from June 2003 to September 2004. The MRI system used was a 1.5T (General Electric) instrument and the images were interpreted by an expert radiologist. Findings: We had 200 patients (mean age: 41.29).There was a high incidence of lumbar canal stenosis (26.5%) 34% of whom were women and 66 % men (p> 0.005). Among the patients, 38.5% were with degenerative disc disorders and 26% with lumbar stenosis. Canal stenosis was found to be higher at lower ages in Iran. Furthermore, 49 % of patients with spinal stenosis weighed 75 kg or more, 62.3 % with a height less than 170 cm, and 58.5 % with occupations involved in lumbar spinal overuse. Mean age of patients with canal stenosis was 41 years old. Conclusion: There was no significant relationship between lumbar stenosis and obesity, short or tall stature, and occupation. Normal or slight bulging disc was more frequent in patients with no stenosis (66% to 49%) and the frequency of disc herniation in the stenotic group was higher than that of non-stenotic group (51% to 34%). Further investigations using large scale sampling are recommended.