RESUMEN
OBJECTIVE: The purpose of this study was to examine the clinical significance of magnetic resonance(MR) image findings according to the lumbar spine instability of patients with lower back pain. METHOD: Total 35 patients with lower back pain underwent lateral flexion and extension radiographs of the lumbar spine as well as MR image. The L3-4, L4-L5, and L5-S1 levels were examined. Horizontal and angular displacements in dynamic radiograph of lumbar spine were used to assess the instability of lumbar spine. MR images were used to evaluate the abnormalities of intervertebral disc, change of adjacent bone marrow, annular tear, disc herniation, and presence of osteophyte. RESULTS: Of the 105 segments, 64 (61.0%) were unstable. Among the 64 unstable segments, 28 were at the L5-S1 level and 21 were at the L4-5 level, respectively. These unstable segments showed higher degree of disc degeneration and more traction osteophyte than the stable segments. No correlation was found between segmental lumbar instability and other findings of MR image. CONCLUSION: For the assessment of lumbar spine instability, dynamic radiographs should be considered in patients with higher degree of disc degeneration or presence of traction osteophyte seen in MR image.