Wound coverage considerations for defects of the lower third of the leg

Abstract

Anatomical features of the lower third of the leg like subcutaneous bone surrounded by tendons with no muscles, vessels in isolated compartments with little intercommunication between them make the coverage of the wounds in the region a challenging problem. Free flaps continue to be the gold standard for the coverage of lower third leg wounds because of their ability to cover large defects with high success rates and feasibility of using it in acute situations by choosing distant recipient vessels. Reverse flow flaps are more useful for the coverage of the ankle and foot defects than lower third leg defects. The perforators in the lower third leg on which these flaps are based are often damaged during the injury. In medium-sized defects of less than 50 cm(2) size, local transposition flaps, perforator flaps, or propeller flaps can be used. Preoperative identification by the Doppler is essential before embarking on these flaps. Of the muscle flaps, the peroneus brevis flap can be used in selected cases with small defects. In spite of all recent developments, cross-leg flaps continue to remain as a useful technique. In rare occasions when other flaps are not possible or when other options fail it can be a life boat. In the author's practice free flaps continue to be the first choice for coverage of wounds in the lower third leg with gracilis muscle flap for small and medium defects, latissimus dorsi muscle flap for large defects and anterolateral thigh flap when a skin flap is preferred.

Keywords: Free flaps; lower leg defects; perforator flaps.

Figure 1

(a) A wound at the lower third of the leg, showing the fracture dislocation of the ankle joint. (b) The real extent of displacement that would have occurred at the time of the accident, in which even the lateral side of the ankle would have been directly exposed to the contaminants. This may escape the scrutiny of debridement predisposing to infection

Figure 2

(a and b) A patient with bilateral lower third leg open fracture with soft tissue loss, (c) both sides covered by gracilis free flap and (d) the result at 5 weeks with complete healing of the wounds

Figure 3

(a) The defect in the lower third leg exposing the fracture site, (b) covered by a reverse flow sural artery flap and (c) shows the obvious donor site

Figure 4

(a) An open fracture dislocation of the ankle which after reduction left a transverse defect which could not be primarily closed, (b) covered by a local transposition flap

Figure 5

(a) A major crush injury of the lower third of the leg, (b) the defect after debridement and the Doppler examination showed good audible signals at X, and a flap marked, (c) the proposed flap elevated on one side and the perforator visualized before the whole flap is raised, (d) the flap raised and rotated through 180 degrees to cover the critical area and (e) a well-settled flap and the healed donor area

Figure 6

(a) A defect on the lateral side of the lower third of the leg and (b) the distally based peroneus brevis muscle raised retaining the last perforator. The clamp is on the proximal perforator to confirm the viability of the muscle with the distal perforator, (c) the muscle turned over to cover the defect and (d) the healed wound with a primarily closed donor defect

Figure 7

(a) Exposed bone in the lower third leg with graft all around in a major crush injury leg with no good proximal recipient vessels. (b) Distally based cross leg flap, where the proximal edge attaches to the length of the defect (c) after completion of reconstruction