Magnetic resonance imaging findings of young adults with low back pain at Nsambya hospital

Abstract

Background: LBP is a common health problem with a global prevalence of 20%(1). The annual prevalence of LBP in Africa is 57%, whereas in Uganda is 20%(2). It peaks between age 35 and 55 years(3). Inspite of the high burden of low back pain among young adults, there is paucity of information on correlation of MRI findings to the clinical complaint in Uganda. For every 10 patients presenting with low back pain to orthopedic clinic in Nsambya hospital, at least three (03) will be young adults. Objectives: The study aimed at determining the MRI findings and their correlation to clinical features. Methods: This was a descriptive cross sectional study design that was carried out in Nsambya hospital, targeting young adults with LBP who presented for MR evaluation from June 2019- Jan 2020. One hundred and fifty-seven patients in the 18 - 39year age group underwent MRI lumbar spine evaluation. Lumbar-sacral spine images in sagittal, axial and coronal planes were obtained using 1.5Tesla MRI machine (Siemens, model-, Town -, County -) and respective scanning protocols. Structured data collection tool was used. STATA version 13.0 was used for data analysis. Correlation was assessed by Pearson chi square tests (Fisher’s exact test) and p-values reported at 0.05 level of significance. MR image patterns were described and grouped into frequencies and percentages. Utility: This study was aimed at describing MRI findings among young adults with LBP in our setting and providing a basis for creation of clinical guidelines for identification and management of LBP. Results: Of the 157 participants, 97 (61.7%) were female, 82 (52.2%) were professionals, 94 (79%) participants were involved in activities that resulted to severe pain. The most affected age group was 24 – 33years with 78 (50%) participants. Eighty-seven (55.4%) participants had pain of gradual onset and 116 (73.9%) had pain of burning nature. The mean duration of pain was four xi weeks. 141 (89.8%) participants had their pain relieved by lying down. 153 (97.5%) had features of degenerative disc disease. Chi square test shows statistical association between age group of 25-34years (AOR=11.42, 95% CI=2.159-60.447 p=0.004) and 35-40 years (AOR=2.42, 95%CI=1.097-5.347 p=0.024); and disc desiccation. There is association between distribution of pain and occurrence of disc desiccation (AOR=1.23 95% CI=0.169-0.885 p=0.024). This study also shows an association between duration of pain and developing marginal osteophytes (AOR=0.07, 95% CI=0.008-0.525 p=0.001); and an association between limb weakness and marginal osteophytes development (AOR=0.707 95% CI=0.323-1.535 p=0.39). Conclusion: Age and pain distribution are predictors of developing disc desiccation. Recommendation: Since disc bulge is the most common MRI finding in this study and can’t be demonstrated on plain x-ray, MRI should be considered as the modality of choice. Young adults who present with acute LBP of burning nature may be recommended for MRI evaluation because they are at a high risk of developing disc desiccation, disc bulge and osteophytes. Patients with severe LBP which radiates to the lower limbs may be recommended for MRI spine evaluation because they have a high chance of having spinal canal stenosis and nerve root compression.