Elevated plasma fibronectin concentrations in patients with ossification of the posterior longitudinal ligament and ossification of the ligamentum flavum.

Fibronectin is a glycoprotein involved in a wide variety of cellular activities, including the development of bone tissues. To study the relevance of fibronectin to the development of ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligamentum flavum (OLF), plasma fibronectin concentrations in 30 consecutive patients with OPLL or OLF and 20 age-and-sex-matched control subjects were measured with an immunonephelometric method. Plasma fibronectin concentrations were significantly elevated in the patients with OPLL or OLF, independently of associated endocrinologic abnormalities, when compared with the control subjects. Because fibronectin is one of the essential factors in endochondral ossification, it is probable that the higher fibronectin concentration in plasma acts as a promoter of the development of OPLL and OLF.