Blood supply of the peroneal tendons: injection and immunohistochemical studies of cadaver tendons.

We studied the vascular pattern of human peroneal tendons with injection techniques and immunohistochemically by using antibodies against laminin The main blood supply arises from the peroneal artery. The distal part of the peroneus longus tendon is supplied by branches of the medial tarsal artery. Blood vessels enter the peritenon of both tendons via a mesotenon from the posterior aspect. From the peritenon, the blood vessels penetrate the peroneus brevis and peroneus longus tendons and anastomose with a longitudinally-oriented intratendinous network. The amount of vessels in the tendon substance is consistently less than in the surrounding peritenon. The distribution of blood vessels in the peroneal tendons is not homogeneous. In the region where the peroneus brevis tendon passes through the fibular groove, the longitudinally-oriented intratendinous vascular network is interrupted and the tendon is almost avascular. In this region, the tendon is squeezed between the peroneus longus tendon and the bony slide bearing of the lateral malleolus. The peroneus longus tendon has two avascular zones. In the region where the peroneus longus tendon curves around the lateral malleolus and the peroneal trochlea of the calcaneus, the anterior part of the tendon which is directed towards the pulley is avascular. A second avascular zone is located more distally in the region where the tendon changes direction and wraps around the cuboid.