ABSTRACT

The most common spinal disorder in adult patients is lumbar spinal canal stenosis (LSCS), causing lower back and leg pain and paresis. Canal stenosis partly results from hypertrophy of the ligamentum flavum. There are only a few studies about ligamentum flavum hypertrophy in the literature, and the exact pathomechanism of hypertrophy is still unknown. A multidisciplinary study involving both clinical and histological approaches was planned. Histological evaluation was performed on 22 ligamentum flavum samples which were collected during surgery for LSCS (12 patients) and lumbar disc hernia (10 patients).

Masson’s trichrome and Verhoeff-Van Gieson elastic stains were performed for each ligamentum flavum to understand the degree of fibrosis and elastic fiber status. There were no statistically significant differences in fibrosis and elastic fiber loss between the two groups. Considering the groups independently, histology showed that with age, ligamentum flavum fibrosis increased and the elastic fibers decreased. In conclusion, increased fibrosis with age is the main cause of ligamentum flavum hypertrophy.