Knee reconstruction using a distally based anterolateral thigh flap: an anatomical cadaveric study

Objective: To study the vascular territory of the descending branch of the lateral circumflex femoral artery and its anastomosis around the knee and to identify the cutaneous perforator supply to the distally-based or reverse flow anterolateral thigh (dbALT) flap. In particular, the distance of the first perforator branch arising from the knee and above region, as well as the number of branches and position of each perforator, beneficial for effective flap design, are also examined. Method: Fresh cadaveric lower limbs were dissected and the distance of the first perforator branch arising from the knee and above regions, which are vascular supplies for flaps, as well as the number of branches and position of each perforator are described. Results: A total of 54 thigh cadavers had at least two cutaneous perforator branches above the knee 10cm from the superior border of the lateral patella. The mean (+/- standard deviation) of the first perforator distance was 2.57 +/- 0.93cm above the superior-lateral border of the patella. All perforating branches were 4 +/- 2cm, 93% were 10 +/- 2cm from the superior lateral border of patella, and 100% were at 20 +/- 3cm (mid-thigh length) which were the traditional anterolateral thigh flap. Conclusion: The dbALT flap technique resulted in constant and reliable references about perforator sites. Thus, this type of flap is a viable option in patients who present with soft tissue defects around the knee and upper third of the leg.