Magnetic resonance imaging characteristics of patients with low back pain and those with sciatica

Shobeiri E, Khalatbari MR, Taheri MS, Tofighirad N, Moharamzad Y
Correspondence: Dr Yashar Moharamzad, yasharpop@hotmail.com

ABSTRACT
Introduction This study aimed to compare the characteristics of magnetic resonance (MR) imaging in patients with low back pain (LBP) and those with sciatica.
Methods Clinical examination and MR imaging were performed on 100 sciatic and 100 LBP patients who were matched by age and gender. Different findings, including spinal canal stenosis, spondylolisthesis, the degree of disc herniation (bulge, protrusion, and extrusion) and nerve root compression, were documented. MR imaging findings were compared using the chi-square and Mann-Whitney U tests.
Results 11 percent of LBP patients and 37 percent of sciatic patients had spinal canal stenosis (p-value is less than 0.001). Spondylolisthesis was found in 12 percent of LBP patients and 14 percent of sciatic patients (p-value is 0.6). Disc extrusion was more common in patients with sciatica as compared to LBP patients at the L4–L5 level (29 percent vs. 4 percent; p-value is less than 0.001) and at the L5–S1 level (24 percent vs. 3 percent; p-value is less than 0.001). Nerve root compression was also more common in sciatic patients in the thecal sac (58 percent vs. 20 percent; p-value is less than 0.001) and in the lateral recess (73 percent vs. 19 percent; p-value is less than 0.001) than in LBP patients.
Conclusion Patients with sciatica were more likely to have spinal canal stenosis, disc extrusion (at L4–L5 and L5–S1 levels) and nerve root compression in the thecal sac and lateral recess.

Keywords: disc extrusion, low back pain, magnetic resonance imaging, nerve root compression, sciatica, spinal canal stenosis
Singapore Med J 2009; 50(1): 87-93