Can Great Toe Pedicle Flaps Have An Impact For Complicated DFUs?
Diabetic ulcers, particularly those located in the forefoot region, pose an interesting challenge for the foot surgeon. When these ulcers occur in the neuropathic patient with adequate circulation, the pedicle flap of the great toe can serve as a useful tool for ulcer management.
Frequently, ulcerations located on the plantar aspect can be difficult to treat because of their late clinical presentation. The presentation often involves large skin and soft tissue defects, extension to bone and insufficient local tissue for closure. Often, local simple treatment options have failed.
Full thickness soft tissue defects can lead to exposure of deep structures including the flexor tendon, plantar plate or the metatarsophalangeal joint (MPJ). When left exposed for a period of time, these structures can become desiccated or infected. Often, the wounds have not responded to a trial of offloading or have healed with an unstable scar and are now subject to recurrent ulceration due to being on a weightbearing surface. For that reason, plantar wounds that have received split thickness skin grafts have the tendency to break down.
Therefore, reconstructive options for midfoot and forefoot ulcerations should be reliable in terms of withstanding weightbearing forces. Since further delay results in worsening of the ulcer, the use of the pedicle flap of the great toe has become an interest over the last few years for soft tissue coverage of diabetic ulcerations of the forefoot.
Key Advantages Of The Great Toe Pedicle Flap
The use of the great toe pedicle flap has several advantages. The primary advantages include tissue based on a known and reliable vascular supply, increased mobility as opposed to a local flap, and avoidance of microvascular anastomosis.1
Given that the flap is based on a known vascular supply, there are a couple of flap design options. It can be a peninsular axial or island-based flap. A peninsular axial flap is one in which the skin covers the pedicle. An island flap affords greater mobility because its pedicle solely consists of the supplying blood vessels. One can use this surgical procedure for smaller defects of the sole, generally defects that are 3.5 cm in diameter or smaller.
Another consideration with flap procedures is donor site morbidity. With the great toe pedicle flap, the donor defect is from a non-weightbearing surface, which does not significantly alter the structure or function of the foot. The donor tissue is more durable, which is beneficial for plantar defects. Since the sole typically consists of sensate glabrous skin with fibro-fatty subcutaneous padding, the selected procedure, when healed, should withstand the plantar and shear pressures associated with weightbearing.
Another advantage is the increased mobility of these flaps due to their defined circulation, which can be based upon the dorsal, plantar or both neurovascular bundles. As a result, they can be proximally or distally based.
Contraindications to performing the great toe pedicle flap include vascular insufficiency, infection, poor quality skin, edema and non-adherence.
Emphasizing The Importance Of Preoperative Vascular Assessment
Due to variation in vascularity, appropriate preoperative vascular assessment with Doppler examination is crucial. In a pedicle flap, blood supply moves through an intact base or stalk. In preparation for selecting a graft, one should perform mapping of the digital arteries to the great toe with a handheld Doppler.