In short. How skin grafts and flaps work, what each needs in order to survive, and how surgeons choose between them when a wound has to be closed surgically.
Key points
- Ask what is at the bottom of the wound.
- A clean, granulating surface with good circulation takes a graft well.
- Exposed bone, tendon, cartilage, or joint needs a flap, because those structures cannot support a graft.
When a wound cannot close on its own and cannot be sutured, two families of operation restore cover. A skin graft takes skin from one part of the body and lays it on the wound, where it must grow a new blood supply. A flap moves tissue with its own blood vessels intact, so it arrives already alive. The choice between them follows from what lies in the wound and how healthy the surrounding tissue is.
Skin grafts
A split-thickness graft takes the epidermis and part of the dermis; a full-thickness graft takes the whole dermis and gives better colour, texture, and contraction behaviour at the cost of a more demanding donor site. Grafts are straightforward and reliable, and they can cover large areas quickly. Their requirement is absolute: the wound bed must be clean, uninfected, and well perfused, because a graft survives first by absorbing nutrients from the bed and only later by growing into it. Grafts bring no bulk, they cannot cover exposed bone or tendon without a vascularised bed beneath, and they tend to contract, which matters across joints. The donor site becomes a second wound that must itself heal.
Graft or flap?
Ask what is at the bottom of the wound. A clean, granulating surface with good circulation takes a graft well. Exposed bone, tendon, cartilage, or joint needs a flap, because those structures cannot support a graft. So does a wound over a weight-bearing area of the foot, where a graft would be thin, fragile, and quick to break down. Flaps are larger operations with their own donor-site cost, and they are chosen when a graft would predictably fail.
Flaps
A flap carries skin, fat, and sometimes muscle or bone with a blood supply that is either kept attached as a pedicled flap or reconnected under the microscope as a free flap. Local flaps borrow neighbouring tissue and are ideal for small defects with a good colour match. Muscle flaps bring blood and infection resistance into a contaminated or deep wound, and are commonly used for pressure ulcers and deep foot defects. A free flap can reconstruct almost any defect, but it is a long operation with a small risk of total failure, and it requires close monitoring afterwards.
What recovery involves
Grafts are usually immobilised for about five days while they take, then mobilised gradually. Flaps need monitoring of colour, temperature, and bleeding for several days, and both leave a donor site with its own scar. Sensation in grafted skin is permanently reduced, and flap skin never regains normal sensation. Appearance is secondary to durable cover, but it is still discussed honestly before surgery.
Seek urgent review if
- A graft or flap turns dark, purple, or black, or becomes cold and swollen.
- Bleeding or discharge increases, or a foul odour develops.
- Fever, spreading redness, or worsening pain appears in the operated area.
Frequently asked questions
When is a flap needed instead of a skin graft?
Ask what lies at the bottom of the wound. A clean, granulating surface with good circulation takes a graft. Exposed bone, tendon, cartilage or joint needs a flap, because those structures cannot support a graft. So does a weight-bearing area of the foot.
Do skin grafts and flaps regain normal sensation?
No. Sensation in grafted skin is permanently reduced, and flap skin never regains normal sensation. Appearance is secondary to durable cover, but it is still discussed honestly before surgery, along with the donor site that becomes a second wound with its own scar.
How long are grafts and flaps kept still after surgery?
Grafts are usually immobilised for about five days while they take, then mobilised gradually. Flaps need monitoring of colour, temperature and bleeding for several days. Both leave a donor site with its own scar and a period of reduced sensation.
Risks & Limitations
- Chronic wounds heal over months, not weeks. A wound that closes in three to six months of consistent care is a good result.
- Recurrence is common. Both diabetic foot wounds and venous leg ulcers frequently return, which is why protective footwear and compression continue after healing.
- Partial or complete failure of a skin graft or flap, which may require further surgery.
- Infection and biofilm, which delay healing by weeks and can spread deeply or into bone.
- Amputation risk in diabetes and vascular disease, which is reduced but never abolished by treatment.
- Prolonged dressings and repeated clinic visits. Offloading, compression, and follow-up are demanding and take months.
- Donor-site scarring and discomfort where a graft or flap was taken.
- Reduced or absent sensation in grafted and flap tissue, and around a healed diabetic foot wound.
When to Seek Care
- A wound that is enlarging or deepening, or that begins to expose bone, tendon, or joint.
- Black, grey, or dead tissue appearing in or around the wound.
- Spreading redness, warmth, or swelling around the wound.
- Fever, shivering, or feeling generally very unwell.
- Foul odour or pus from the wound.
- New or severe pain, including pain in the leg or foot at rest or at night.
- A toe or foot that turns black, cold, or blue.
- Loss of sensation in a foot or toe, or a new wound or blister you cannot feel.
References & Further Reading
- World Health Organization (WHO) — chronic wound and diabetes care resources
- NICE (National Institute for Health and Care Excellence) — guidance on wound care, diabetic foot problems, and pressure ulcers
- Wounds International — international consensus documents on wound infection, biofilm, and compression therapy
- American Society of Plastic Surgeons (ASPS) — plastic surgery guidance on wound closure
- Cochrane Library — systematic reviews in wound care and wound closure
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.