Anatomical study of perforators of posterior upper and middle third of leg to assess feasibility of combined gastrocnemius flaps

Abstract

A common problem seen in the plastic surgery referrals for management of fractures of the leg is the loss of tissue cover over the tibia. This is probably due to the fact that the anterior border of tibia is subcutaneous and prone to loss of tissue following road traffic accidents. To solve this problem a large amount of tissue is required which is mostly available on the posterior aspect of the leg. In order to move this tissue without risk of necrosis the flap must be supplied by an adequate number of perforator vessels. Therefore we decided to study the anatomy of perforators of the sural artery along with the posterior tibial and peroneal system so that the anatomical basis of a combined flap may be defined. : We performed cadaveric dissection in 20 legs to note the location of the proximal and distal most perforators arising from the sural, peroneal and posterior tibial arteries on the posterior aspect of the leg extending from the intercondylar line up to 8cm proximal to the medial an lateral malleolus. The area of medial belly of gastrocnemius with the adjacent posterior tibial perforators was designated as the medial flap and the area over lateral belly of gastrocnemius with adjacent peroneal perforators was designated as lateral flap. In the area defined as the medial flap we found an average of 2.5 perforators arising from the medial sural artery and 1.7 arising from the posterior tibial artery. In the medial flap the distal most perforator was the posterior tibial septocutaneous perforator, which was at an average 23.3cm from the intercondylar line, around 6.8 cm farther away from the distal most medial sural perforator. In the lateral flap region we found an average of 1.7 lateral sural perforators along with 1.5 peroneal perforators. In this flap the distal most perforator was the peroneal septocutaneous, at an average distance of 23.1cm distal to the intercondylar line and at an average of 7.3cm further away from the distal most lateral sural perforator. On examination of the anatomical basis of the combined medial and lateral flap it is possible to raise long flaps of around 25-30 cm, which would be ideal to resurface long defects on the anterior aspect of leg. Raising these flaps with the gastrocnemius muscle in the flap would help to increase the axis of rotation of the flap allowing the flap to move to the anterior aspect of leg and even for resurfacing large defects over the knee