Blood supply of the tibialis anterior tendon.

Injection techniques and immunohistochemical methods (antibodies against laminin) were performed to uncover the vascular pattern of the human tibialis anterior tendon with regard to spontaneous rupture of this tendon. Proximally, the blood supply of the tibialis anterior tendon mainly arises from the anterior tibial artery. Distally, the tendon is supplied by branches of the medial tarsal artery. Blood vessels enter the peritenon via vinculae from the posterior side. From the peritenon, the blood vessels penetrate the tendon and anastomose with a longitudinally orientated intratendinous network. Compared with the surrounding peritenon, the number of vessels in the tendon substance is greatly reduced. The distribution of blood vessels within the anterior tibial tendon is not homogenous. The posterior part of the tendon has a complete vascular network that extends from the musculotendinous junction to the insertion at the bone. In the anterior half of the tendon, there is an avascular zone between 45 and 67 mm in length. The location of the avascular zone correlates well with the location of the most frequent site of spontaneous rupture of the tibialis anterior tendon reported in the literature. Hypovascularity has to be considered as an etiological cofactor for spontaneous rupture of the tibialis anterior tendon.