Significance of spinal canal and dural sac dimensions in predicting treatment of lumbar disc herniation.

This retrospective study was performed to investigate the significance of quantitative MRI measurements of spinal canal and dural sac dimensions for treatment decisions and clinical outcome of lumbar disc herniation. 182 patients (111 nonsurgical patients and 71 surgical patients) were included, while 78 nonsurgical patients and 50 surgical patients were enrolled in the final follow-up. The initial JOA score in nonsurgical patients was significantly superior to surgical patients (t-test: p < 0.001), whereas the final JOA score and the rate of improvement were not significantly different between the two groups of patients (t-test: p > 0.05). 88.46% of nonsurgical patients and 90.00% of surgical patients had a good or excellent outcome (chi-square test: p > 0.05). However, if the 16 recurrent cases were included, the proportions dropped to 75.82% and 84.90% for nonsurgical and surgical patients, respectively. Compared with nonsurgical patients, quantitative parameters, such as midsagittal diameter and available diameter of spinal canal, lateral recess width and cross-sectional areas of spinal canal and dural sac, were significantly smaller in surgical patients (t-test: p < 0.001), and was reflected in the initial JOA score (128 cases; Spearman rank correlation coefficient: r 0.01 = 0.486, 0.499, 0.493, 0.507, 0.484; p < 0.001). The spinal canal and dural sac dimensions were important predictive factors for treatment selection of lumbar disc herniation.