Answer:
There are 4 fasciocutaneous flaps in the leg: anterior tibial artery flap, the peroneal artery flap, the posterior tibial artery flap, and the sural artery flap.
The anterior tibial artery flap: located along the anterolateral aspect of the leg between the knee and lateral malleolus, type B type circulation. The dominant pedicle is the septocutaneous branches of the anterior tibial artery and venae comitantes. The standard flap is proximally based and will provide tibial coverage to the upper, middle, or lower third of the leg. The reverse flap can be used to cover the middle third of the leg, or for malleolar and foot coverage. Precautions concerning these flaps include: a) lower extremity venous insufficiency is a relative contraindication to reverse or distally based flaps; despite a normal LE venous system, vascular insufficiency in the reverse flap is a potential problem; b) preoperative arteriogram or Doppler studies to determine the vascular anatomy are recommended because the anterior tibial artery may be absent or occluded from trauma or disease.
The peroneal artery flap: involves the skin located over the lateral leg centered over the fibula, between the lateral head of the gastrocnemius and the lateral border of the tibialis anterior. It is a type B flap, with the dominant pedicle being the 5-6 segmental septocutaneous arteries and venae commitantes of the peroneal artery. The minor pedicle includes musculocutaneous perforating vessels from the peroneus longus, peroneus brevis, FHL, lateral gastroc, EDL, and EHL muscles. The flap can be elevated from the lower third of the lateral leg to the level of the middle third of the fibula, or can be distally based and rotated inferiorly. The precautions here are similar as for the anterior tibial flap. Reverse flap designs are often unreliable because of inadequate reverse flow in the peroneal artery due to distal vascular injury or disease.
The posterior tibial artery flap: involves the medial aspect of the leg extending from the knee to medial malleolus. It is a type B flap, with the dominant pedicle being the septocutaneous perforators of the PT artery. The standard flap can be used to cover the middle or lower third of the leg, as can the distally based flap. Precautions include: the PT artery needs to be palpable in the distal leg in order for safe flap elevation to be possible; the posterior tibial nerve is subject to injury during flap elevation.
The sural artery flap: is located between the popliteal fossa and the middle leg, centered over the midline raphe between the heads of the gastrocnemius. The flap has type A circulation with the dominant pedicle being the direct cutaneous artery (sural artery branch) and lesser saphenous vein of the popliteal artery and vein. The standard flap can be used to cover the upper third of the posterior leg, or swung anteriorly to cover the anterior knee.