Subfascial Directionality of Perforators of the Distal Lower Extremity An Anatomic Study Regarding Selection of Perforators for 180-Degree Propeller Flaps

Background: The 180-degree propeller flaps allow closure of soft-tissue defects of the distal lower extremity. In addition to twist, the pedicle is often subject to additional kinking which increases proportionally to the angle at which the perforator pierces through the fascia. This study evaluates the directionality of the perforators at the fascial level to guide in the selection process of the best perforator. Material and Methods: Perforators were identified in the lower extremities of 16 fresh cadavers. The angle of fascial perforation was measured. Perforators were grouped according to source vessel and location. Results were analyzed statistically regarding angle of fascial perforation along the source vessel and region. Results: A total of 324 perforators were identified. Distal perforators pierced the fascia at a significantly greater angle than in the proximal and middle segment of the peroneal and anterior tibial vessels (P < 0.005). Perforators originating from the posterior tibial artery pierced the fascia at less acute angles distally. When grouped according to the region of the perforators, no significant difference was found between perforators from all source vessels in the proximal region of the distal lower extremity. Even distally, perforators from the posterior tibial artery traveled almost perpendicular (P < 0.005). Conclusion: Perforators traveling in a near perpendicular manner are ideal to serve as a pedicle for 180-degree propeller flaps as solely the twist has to be distributed along the vessel. The posterior tibial artery was the source to perforators with the most constant, near-perpendicular course, predisposing them for use in 180-degree propeller flaps.