AIM: To histopathologically evaluate and compare bone morphogenetic protein (BMP)-2, vascular endothelial growth factor (VEGF), and vitamin D receptor (VDR) levels in the ligamentum flavum (LF) of patients with lumbar spinal stenosis (LSS) and lumbar disc herniation (LDH).

MATERIAL and METHODS: Surgical specimens of the LF in 25 patients who underwent surgery for LDH and 25 patients who underwent surgery for LSS were examined histopathologically. The prevalence and severity of BMP-2, VEGF, and VDR immunoreactivity were evaluated to create histoscores (prevalence × severity), which were compared between groups.

RESULTS: The mean BMP-2 histoscore was similar in both groups. In the LSS group, the mean VEGF histoscore was significantly higher and the mean VDR histoscore was significantly lower.

CONCLUSION: Elevated VEGF and decreased VDR levels in the LF in LSS are associated with more intense inflammation and chronic process of the disease. The prominent expression of BMP-2 in the LF in both diseases suggests that BMP-2 might be affected by inflammation regardless of chronic pressure and degeneration.