Association between clinically diagnosed lumbar intervertebral disc prolapse and magnetic resonance image findings

Abstract

There are contradictory reports on the findings of magnetic resonance image (MRI) in lumbar intervertebral disc prolapse. A study was conducted on 54 patients using 3 of 4 clinical criteria (low back pain with radiation down to the lower limbs, radicular pain along specific dermatomes, positive straight leg raising test, presence of neurological symptoms and signs e.g. motor or sensory deficit and MRI of lumbosacral spine of the respondent). Evaluation of MRI of lumbosacral spine was done based on extent of disc prolapse, disc degeneration, nerve root compression neural foramen compromise. The logistic regression analysis between the findings of MRI and the clinical features show that there was a significant association in the neural foramen or lateral recess (Odd's ratio 7.106, p<0.05), the root compression (p<0.01) as well as the disc extrusion (p<0.05). There was no statistical association between clinical levels and other MRI findings like disc protrusion and disc bulge (p value 0.21 and 0.14, respectively). The strength of agreement between clinical and MRI diagnosis level of disc prolapse was calculated using kappa statistics (k-value). The test revealed a very good agreement for L3/4 (k-value = 0.812) and good agreement for L4/5 and L5/SI  level (k-value 0.75 and 0.75 respectively) between these two procedures, suggesting that level of disc prolapse could be correctly  diagnosed without MRI findings.  In conclusion, clinically diagnosed levels associate well with MRI levels, but all MRI abnormalities do not have any clinical significance.