Tensile Test of Human Lumbar Ligamentum Flavum: Age-Related Changes of Stiffness
Atsushi Mihara, Norihiro Nishida, Fei Jiang, Junji OHGI, Yasuaki Imajo, Hidenori Suzuki, Masahiro Funaba, Hiroki Yamagata, Xian Chen, Takashi Sakai
Abstract
The most common cause of lumbar spinal canal stenosis is age-related degenerative changes. The ligamentum flavum is said to become thicker and stiffer with age, based on several histological and cadaver studies. However, there are no studies determining the age-related changes of the mechanical properties of the ligamentum flavum in live patients. We examined the mechanical properties of the ligamentum flavum of live patients and evaluated the age-related changes. A total of 44 patients undergoing decompression surgery due to lumbar disease at our institute were included. The ligamentum flavum was harvested from the decompression site as a part of a necessary procedure for decompression. The tensile test was performed for the harvested ligamentum flavum within 24 h of harvest. Age-related changes in the stiffness of the ligamentum flavum were evaluated. Age was the only factor that showed a significant correlation with stiffness on multiple regression analysis. We demonstrated that the mechanical properties of the ligamentum flavum change with age.