98. Influence of estrogen to the spinal ligament ossification: an in vitro study using cultured human spinal ligament cells

BACKGROUND CONTEXT: Previous studies suggest many factors (genetic factors, dietary habits, mechanical stress to the PLL, production of cytokines or growth factors in the PLL tissues etc.) for causation of OPLL, but etiology of this disease is still unknown. On the other hand, female sex steroid hormones, especially estrogen is known that has anabolic action in bone metabolism. And occurrence of this disease of the female-to-male ratio is estimated to be approximately 1:2. Hence, we hypothesize that estrogen might be one of causative factor for OPLL.