MRI manifestations and pathologic significance of interspinous ligaments in degenerative lumbar spinal diseases

    WANG Yi, GONG Shuiª²Gen, ZHANG Weiª²Guo, CHEN Jinª²Hua, TAN Yong

    Department of Radiology, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042, China

    ¡¾Abstract¡¿ AIM: To explore the magnetic resonance imaging (MRI) features and their pathologic significance of the interspinous ligaments in degenerative lumbar spinal diseases. METHODS: Thirty healthy volunteers (normal group) and 30 patients with degenerative lumbar spinal diseases (study group) underwent examinations of functional radiography and MRI. The MRI features of the interspinous ligaments L1ª²S1 were classified as five categories according to their signal intensities: type 1A, 1B, 2, 3 and 4. Ten interspinous ligament specimens were selected for the histological examination. RESULTS: In the normal group, 94% interspinous ligaments were classified as type 1A, while in the study group interspinous ligaments were 60 type 1A, 31 type 1B, 18 type 2, 16 type 3 and 25 type 4. The average age and the disc degeneration grade of the patients with type 1B were significantly higher than those of other types. Instability was found to be associated with type 2 rather than types 1A and 1B. The histological examination showed that the ossification and necrosis of fiber bundle predominated over type 1B, proliferation of inflammatory cells over type 2 and fatty degeneration over type 3. CONCLUSION: Lumbar spinal MRI is helpful in identifying normal and various kinds of pathological changes in the interspinous ligaments. ......