Skin grafts and flaps to close foot wounds

Closing a wound with your own skin

Steady wound care and offloading are the foundation, and many foot wounds close with them. Some become clean and healthy but are too large, or shrink too slowly, to finish on their own. For those, a skin graft or flap can close the gap with surgery. Many studies have shown grafting to be an effective way to cover diabetic ulcers quickly.⁠^[7]

Surgeons picture these choices as a reconstructive ladder, from letting a wound heal from its base, through stitches and grafts, up to flaps. It is a planning tool, not rungs you must climb one at a time.⁠^[2]

Dr. Efe Ozturk, a Foot and Ankle Surgeon who is board certified in wound care (FAPWH), performs split-thickness skin grafts and local flaps for the wounds that need them. He chooses the simplest option that will close your wound and hold up.

How a graft differs from a flap

A split-thickness skin graft takes the outer layer of skin and part of the layer beneath it from a donor site, often the outer thigh. It can be meshed with rows of small slits so it covers a larger area and lets fluid drain.⁠^[1] With no blood supply of its own, a graft relies on the wound bed until new vessels grow in.⁠^[1]

A flap, unlike a graft, brings its own blood supply.⁠^[1] A local flap uses skin right beside the wound, draws blood from the fine network of vessels just under the skin and suits smaller wounds. Larger wounds may need a regional flap, carried on a named artery from elsewhere on the same limb, or a free flap, moved from a distant part of the body with its vessels reconnected by microsurgery.⁠^[2]

Grafts can also be made from donated human tissue, animal tissue or engineered products.⁠^[1] Dr. Ozturk applies these skin substitutes in the office when a wound needs one.

When a graft or flap is considered

When wound care and offloading have not closed a diabetic foot wound, surgeons may consider a local flap for definitive closure, chosen by the wound’s size, location and type.⁠^[8] Grafting has been proposed mainly for infection-free diabetic wounds on the leg and the top of the foot,⁠^[3] but grafts have also been used on the sole⁠^[7] and to close wounds at the site of an earlier partial foot amputation.⁠^[5]

Before closing a wound, we want four things in place:

• A clean wound bed. Dead tissue and infection are cleared first, with debridement in the office or, for a deep infection, surgery for diabetic foot infection. An infection-free base helps a graft take.⁠^[1]
• Enough blood flow. We check circulation with noninvasive testing at our practice and, if it is reduced, refer you to a vascular specialist to restore it first. See circulation tests for foot wounds.
• A plan for pressure. Grafts on the sole can give lasting closure when patients are chosen carefully and the foot is offloaded after surgery.⁠^[7] If a bony prominence or tight tendon caused the ulcer, surgery that takes pressure off may be part of the plan.
• No smoking. In 83 people with diabetes, a current or past smoking habit was linked to graft complications.⁠^[5] Read why smoking and diabetes slow surgical healing (external site).

How the operation is done

The wound bed is cleaned back to healthy tissue. For a graft, a thin sheet of skin is taken from the donor site, usually with an instrument called a dermatome, then laid onto the wound and secured.⁠^[1] A dressing holds it in place.

Negative-pressure wound therapy can serve as that dressing. In a review of 10 randomized trials with 488 people, grafts covered with it took better, people went home sooner and fewer needed another operation. Side effects did not rise, though data on them were limited, and the trials covered skin grafts in general, not only on the foot.⁠^[9] We use negative-pressure wound therapy for the wounds that need it.

For a local flap, the skin beside the wound is freed while staying attached at its base, then advanced, rotated or swung across the gap. The spot it came from is closed in the same repair.⁠^[2]

What the results show

• Grafts in people with diabetes. Across 11 studies, 85.5% of grafted ulcers healed, taking about 5.4 weeks on average, with about two years of follow-up; 4.2% recurred and 12.1% needed regrafting. The authors called for wider use of grafting for clean, hard-to-heal ulcers of the leg and top of the foot.⁠^[3]
• A surgical series. Of 83 people with diabetes, 65% healed without problems and 28% needed regrafting; every wound was closed by final follow-up.⁠^[5]
• Chronic wounds in high-risk patients. Of 94 people with chronic leg and foot wounds, 66 of them with diabetes, 69.1% healed with full graft take and 19.1% needed a revision. Healing was similar with and without diabetes, and on the sole versus elsewhere.⁠^[6]
• The sole of the foot. In a study of 182 people, grafted wounds on the sole were less often healed at one year (38% versus 64% elsewhere), though time to full healing was similar. Wounds came back in 17% on the sole and 10% elsewhere, not a significant difference.⁠^[7]
• Local flaps. Across 25 studies covering 204 local flaps in 199 people, 75.5% had a closed wound at last follow-up. Most studies were retrospective case series of generally low quality, so the authors advised caution.⁠^[4]

These are results in selected patients, not a promise for every wound.

Recovery

Until the graft has taken, the area is protected and you keep weight off it. For a graft or flap on the bottom of the foot, we fit an offloading device and show you how to get around safely. The donor site is a shallow wound that can resurface within two to three weeks.⁠^[1]

We usually see you every week or two while it heals, measuring the wound each visit. See recovery after limb salvage surgery.

Grafted skin often looks smoother and paler than the skin around it, and a meshed graft is more easily injured and has less feeling.⁠^[1] Daily foot checks and our therapeutic shoes and inserts help protect it; see keeping your foot in remission.

Risks and limits

• Partial take and infection. Part of a graft may not attach, and that area may need regrafting. Infection affected 4.4% of grafted ulcers, and donor-site infection was reported in about 1.7%.⁠^[3]
• Kidney disease. In one study, people on dialysis needed graft revision about three times as often (46.2% versus 14.8%), though over time their wounds healed at a similar rate.⁠^[6] See foot wounds with kidney disease.

A graft covers the wound but doesn’t remove the pressure that caused it, so offloading continues. Any operation also carries the risks of anesthesia and blood clots. If a graft or flap doesn’t take, the reconstructive ladder offers other ways to close the wound.⁠^[2] See limb salvage surgery for the wider plan, and if you’ve been told a wound means losing part of your foot, consider a second opinion before amputation.

Questions to ask

• Is my wound clean, and is my blood flow good enough?
• Would a graft or a flap suit my wound better, and why?
• How long will I keep weight off the foot?
• What will keep this wound from coming back?

When to seek care

See us within a day or two for any foot wound that isn’t healing, especially if you have diabetes. If you have diabetes or poor circulation, call us the same day if you think a wound may be infected, such as a red, hot, swollen foot, or if you have new foot pain at rest or at night.