Magnetic resonance imaging (MRI) patterns among patients with low back pain attending MRI centres in Eldoret, Kenya

Abstract

Background -Low back pain (LBP) is the most prevalent musculoskeletal condition and one of the most common causes of disability. Patients presenting with LBP require diagnostic imaging to determine the cause. Plain spine x-ray examinations are readily available, but have a low yield of findings, necessitating evaluation by MRI. The aim of this study is to find out MRI patterns in LBP a practice that is well established in developing countries, but is not well documented in the developing world due to the high cost of MRI and its unavailability Objective: To determine the MRI patterns among patients with low back pain attending MRI centres in Eldoret, Kenya. Setting: The Radiology and Imaging departments of the Eldoret and Mediheal Hospitals in Eldoret, Kenya. Study Design: This was a cross-sectional study. Subjects: Adult patients with LBP referred for lumbar spine MRI. Methods: 185 patients with LBP, who met the inclusion criteria, underwent MRI from October 2011 to April 2012. Sampling was done using Fischer’s formula and adjusted for finite population taking into account the number of MRIs done in a month. Data was analyzed using STATA version 10. Descriptive statistics were carried out for continuous variables using mean, median, standard deviation and inter-quartile range. Frequency tables were generated for categorical variables. The chi square test and Fishers’ exact test were used to test for associations. A p-value < 0.05 was considered statistically significant. Results: The median age was 47 years and mean age was 47.32 ±14 years. LBP was seen in 50.81% men and 49.19%. M: F was1: 0.97. The main presenting complaints were LBP in 65.95%, radiating LBP in 30.81% and LBP with inability to walk in 3.24%. The median duration was 1 year and the mean was 3.79±5.82 years. 79.46% had no history of trauma. Predominant occupations were 36.22% office workers, 17.30% farmer, 4.32% student, 12.97% housewife and 18.38% laborers. The patterns identified on MRI included: 80% degenerative disc disease, 23.78% lumbar spondylosis, 4.86% infections, 9.73% neoplasms and 15.68% other anomalies. 65.41% bulges and 23.24% herniations (62.79% broad based, 6.98% extrusions, 30.23% protrusions) were reported. The most common site for degenerative findings was L4/L5 followed by L5/S1. Nerve root compression was the most common complication. No association between lumbar disc degeneration (LDD) and sociodemographic factors was found. Conclusion: MRI is useful in detecting LDD which is common in the lower lumbar regions of both sexes.