Hypertrophy of the ligamentum flavum and expression of transforming growth factor beta

OBJECTIVE: To explore the relationship between cellular apoptosis and hypertrophy of the ligamentum flavum in the lumbar region. METHODS: Thirty patients with lumbar spinal stenosis were evaluated. Hypertrophy of the ligamentum flavum was present in 15 patients and absent in 15. Hematoxylin–eosin staining and transforming growth factor beta (TGF-β) immunohistochemical testing were applied to compare these two groups. RESULTS: Derangement of fibrous alignment, fibrocartilage changes, and infiltration of inflammatory cells were observed in the patients with hypertrophy of the ligamentum flavum, while fibrous alignment was normal and few inflammatory cells were observed in patients without hypertrophy. Immunohistochemical studies showed positive expression of TGF-β in patients with hypertrophy, while expression was negative in patients without hypertrophy. The integrated optical density was 2.6556708 in the hypertrophy group and 23104671 in the normal controls. CONCLUSIONS: Expression of TGF-β was closely related to hypertrophy of the ligamentum flavum. Appropriate application of the TGF-β expression level can be used to predict progression of hypertrophy of the ligamentum flavum.