Simplified soft tissue coverage of the distal lower extremity: The reverse sural flap

Abstract

Soft tissue defects involving the distal lower extremity present challenging problems for orthopaedic surgeons to manage. Historically, wounds not amenable to primary closure have necessitated assistance from multidisciplinary teams using plastic surgeons to obtain adequate soft tissue coverage through rotational flap or free tissue transfer procedures. Techniques related to soft tissue rearrangement and local rotational flap coverage have advanced over the years with a growing knowledge of local anatomy and vasculature. The reverse sural flap may be performed to cover soft tissue defects within 10 cm of the foot or ankle region, negating the need for microvascular intervention. The simplistic nature of the reverse sural flap is appealing to orthopaedic surgeons as a means to provide timely patient care without additional support because it does not require microvasculature work or the need for intraoperative microscopes and has been popularized among orthopaedic trauma surgeons as a necessary tool to possess. Here, we discuss the reverse sural flap to include history, relevant anatomy, clinical indications, and a description of the technique for application.

Keywords: coverage; flap; reverse; rotational; soft; sural; tissue.

FIGURE 1.

A 31-year-old man undergoing limb salvage through plate-assisted bone segment transport to an ankle arthrodesis after sustaining a left type IIIB open pilon fracture with significant bone and articular cartilage loss. A, Anteromedial ankle wound with skin necrosis at the traumatic wound site. Patient positioning: Supine. B, Wound appearance after debridement and irrigation. No signs of infection were encountered, and the wound was deemed appropriate for coverage. The patient was indicated for reverse sural flap given exposed tendon and bone. Patient positioning: Prone.

FIGURE 2.

Determination of pedicle length. A, A sterile flexible ruler is used to template the necessary pedicle length for rotation of the desired flap. Appropriate slack must remain in the pedicle to negate kinking of the vascular supply originating from the lateral ankle. B, Donor site planning. Pedicle dissection should begin at a minimum of 5 cm above the tip of the fibula to avoid injury to the lateral perforators. Pedicle width is drawn to 4 cm and marked proximally to the previously determined length. Flap paddle (arrow) dimensions are traced using the paper template at the proximal extent of the pedicle.

FIGURE 3.

Skin is incised (A) longitudinally along the central aspect of the pedicle with (B) subsequent elevation of subdermal skin flaps using a knife.

FIGURE 4.

Flap dissection. A, The flap paddle is elevated subfascially taking care to remain within the fascial plane. B, The proximal sural neurovascular bundle (arrow) enters along the superomedial aspect of the flap paddle and is transected. C, Subfascial dissection is continued distally along the pedicle, maintaining a 4-cm pedicle width. D, Vascular branch of the peroneal perforator (arrow) visualized laterally at the distal extent of the pedicle.

FIGURE 5.

Rotation of reverse sural flap after completed dissection. (A) Appearance of donor site and flap after completed dissection. (B–C) The flap paddle and pedicle are tunneled medially under a skin bridge and placed over the wound bed. Tunneling should be avoided in the event undue tension is placed across the pedicle, in which case the skin should be incised to preserve the vascular supply.

FIGURE 6.

Final appearance of wound after reverse sural flap placement. A, The flap paddle is secured in place over the wound bed using a combination of 3-0 nylon and 3-0 chromic suture. B, Skin amenable to primary closure is closed using suture. Split thickness skin graft is harvested to provide coverage over the flap paddle donor site and distal pedicle. A wound vacuum dressing is applied over the flap and donor site.