The longitudinal assessment of imaging and disability of the back (LAIDBack) study - Baseline data

Study Design. Prospective cohort study of randomly selected Veterans Affair s (VA) outpatients. Objective. To determine the prevalence of magnetic resonance imaging (MRI) findings in the lumbar spine among persons without current low back pain or sciatica and to examine which findings are related to age or previous back symptoms. Summary of Background Information. Previous studies of patients without low back pain have not explored the possible association of various MRI findin gs to past symptoms. Methods. We randomly selected an age-stratified sample of subjects without low beck pain in the past 4 months from clinics at a VA hospital. We collec ted information on demographics, comorbidity, functional status, and qualit y of life. MR images were obtained using a standardized protocol through ea ch of the five lumbar disc levels. Results. Of 148 subjects, 69 (46%) had never experienced low back pain. The re were 123 subjects (83%) with moderate to severe desiccation of one or mo re discs, 95 (64%) with one or more bulging discs, and 83 (56%) with loss o f disc height. Forty-eight subjects (32%) had at least one disc protrusion and 9 (6%) had one or more disc extrusions. Conclusion. Many MR imaging findings have a high prevalence in subjects wit hout low back pain. These findings are therefore of limited diagnostic use. The less common findings of moderate or severe central stenosis, root comp ression, and extrusions are likely to be diagnostically and clinically rele vant.