Enlarged perforating branch of peroneal artery and extra crural fascia in close relationship with the tibiofibular syndesmosis.

We found an extremely large perforating branch of peroneal artery in an 89-year-old female cadaver's left ankle. The anterior tibial artery could not reach to supply the ankle and dorsum of the foot. The perforating branch of peroneal artery continued as the dorsalis pedis after giving off an anterior lateral malleolar artery branch. The posterior tibial artery was thinner than usual. On the anterior side of the ankle, there was an extra crural fascia in addition to the regular crural fascia, under the anterior crural muscles. This strong fascia was tightly overlying the perforating branch of peroneal artery and anterior tibiofibular ligament. It is important to know the relationship of these vessels to the surrounding structures. Surgeons must be careful while dissecting this area since the perforating branch of peroneal artery might be anomalously enlarged as well as crossing in front of the tibiofibular syndesmosis in order to prevent vascular injury.