1. The document provides an algorithm for selecting appropriate flaps to reconstruct lower extremity defects, discussing various options from primary closure to free flaps. 2. It begins by covering primary and secondary wound closure, then skin grafts including split-thickness and full-thickness grafts. 3. Next it discusses flaps in general and provides classifications. It then details various local, regional, and free flap options for reconstruction, including musculocutaneous flaps like the gastrocnemius and latissimus dorsi flaps.

1. Algorithm to approach the lower
extremity defect and to select
appropriate flaps for reconstruction:
from lecture to practical
Dr. Tran Phuoc Binh

2. Content
1. Primary and secondary wound closure
2. Skin grafts
3. Flaps in general
4. Local flaps
5. Regional flaps
6. Free flaps

4. 1. Primary and secondary wound closure
1.Primary wound closure:
• Once the wound has been debrided and irrigated, the physician must
determine whether it is amenable to closure based on the time since injury,
location, availability of tissue for a tension-free suture as well as the level of
contamination.

5. Systemic factors and associated conditions must also be
taken into consideration when deciding whether to close
a wound primarily or not . These include:
• history and mechanism of injury
• associated injuries
• patient age
• vascular status and/or diabetes mellitus
• immune function
• coagulation status.

6. Absolute contraindications Relative contraindications
Heavily contaminated wounds (stagnant
water, farmyard, etc
Wounds older than ~12 hours
Large soft-tissue defects (high-energy
weapons, shotgun)
Animal or human bites (except facial
bites)
Closure requiring excessive tension Underlying fractures (controversial)
Puncture wounds Acute fasciotomy wounds
Absolute and relative contraindications for primary wound closure.

7. • Too much tension on the wound edges is the greatest enemy of primary
wound closure. If in doubt, it is often better to leave the wound open and
only close it secondarily
• An important factor to include in the decision for primary closure is the
time interval since the injury.
• The wound debridement and irrigation should occur within 6–8 hours,
although some would consider 12 hours to be acceptable

9. 1. Primary and secondary wound closure
2. Secondary wound closure:
• When primary closure is not immediately possible, delayed primary closure
may be considered.
• The disadvantages of secondary closure are:
• prolonged length of time for closure (up to several weeks)
• risk of infection
• much larger scar
• necessity for continued wound care while handling

10. 2. Skin graft
1.Split-thickness skin grafts
Definition Split-thickness skin grafts (STSGs) are composed of epidermis,
including the basal membrane, and a variable thickness of dermis.
Split-thickness skin grafts may be subdivided into:
• thin (0.008–0.012 mm)
• medium (0.012–0.018 mm)
• thick (0.018–0.030 mm) grafts.

11. 1.Split-thickness skin grafts
Indication
Split-thickness skin grafts are most commonly used :
• The defect needing to be covered is of substantial size.
• Precluding the use of a full-thickness skin graft
• Cosmetic concerns are not essential.

12. 1.Split-thickness skin grafts
Advantages
• The coverage of large wounds (including lining of cavities),
• Resurfacing of soft-tissue defects,
• Coverage of muscle flaps
• Closure of flap donor sites.
• The donor sites of split-thickness skin grafts heal spontaneously within 7–14 days
• Donor sites usually allow for reharvesting once healing is complete.
• However, with each increase in thickness of the graft, healing time will be prolonged.

13. 1.Split-thickness skin grafts
Disadvantages
• Split-thickness skin grafts are rather vulnerable
• They appear to be smoother and shinier than normal skin because the appendices
of normal skin are missing.
• They often show inhomogeneous pigmentation, ie, hypo- or hyperpigmentation,
particularly in darker-skinned individuals.
• The thinness, smooth texture, and lack of hair growth render these grafts rather
more functional than cosmetically attractive.
• Last but not least, the wound created at the donor site is often more painful than
the recipient site

15. 2. Skin graft
2.Full-thickness skin grafts
Full-thickness skin grafts (FTSGs) are composed of epidermis and the entire
dermis.
The thicker the dermis, the better the nature of normal skin will be achieved after
grafting.

16. 2. Full-thickness skin grafts
Indication
1. The use of full-thickness skin grafts is indicated in defects, in which the
adjacent tissues are rather immobile or scarce.
2. Full-thickness skin grafts are ideal for exposed areas of the face that are not
suitable or accessible to local flaps.
3. Specific locations that lend themselves well to full-thickness skin grafts in
the face are:
• nasal tip
• eyelids
• forehead
• ears.

17. 2. Full-thickness skin grafts
Disadvantages
• The application of full-thickness skin grafts is limited to relatively small,
uncontaminated, well-vascularized wounds.
• Full-thickness skin grafts require more favorable wound bed conditions for
engraftment and survival, because of the thicker amount of tissue requiring
revascularization.
• Donor sites must be closed primarily or, more rarely, first resurfaced with a split-
thickness graft from another site

19. 3. Flaps
• A flap is a unit of one or more tissues that maintains its own blood
perfusion through a vascular pedicle, while being transferred from a donor
site of the body to a recipient site, where it is needed.
• Flaps are required in order to cover tissue defects that have poor vascularity
or which expose foreign bodies such as implant material.
• Flaps range from a simple advancement of skin and subcutaneous tissue to
so-called composite units that may consist of any type of tissue including
skin, subcutaneous tissue, muscle, bone, fascia or even nerve.

20. 3. Flaps
Classification of flaps
• Type and anatomy of vascular supply (ie, source vessel)
• Method of tissue transfer (ie, technique of flap elevation and
movement)
• Flap composition (ie, tissues that constitute the flap).

21. 3. Flaps
Classification according to the type of transfer
Local skin flaps:
• Advancement: advances along the long axis of the flap, from the base towards
the defect. (V-Y advancement is a modification of the advancement flap).
• Rotation: rotation about a pivot point into the defect
• Transposition: rotation about a pivot point into the defect with lateral
movement
• Interpolation: rotation about a pivot point into the defect that is nearby but
not directly adjacent to the donor site, so that its pedicle must pass over or
under the intervening tissues.

22. 3. Flaps
Classification according to the type of transfer
Regional flaps have the base of their pedicle in contiguity with the defect and
the skin on the same extremity .If the pedicle consists of the vascular bundle
only, without subcutaneous tissue and skin, the flaps are called island flaps.
Distant flaps are required when the recipient site or tissue defect is not in
close vicinity to the donor site or because there is no healthy soft tissue
adjacent to the wound. They are divided into two categories:
• attached direct distant flaps
• free flaps

23. 3. Flaps
Classification according to tissue composition
• Cutaneous
• Fasciocutaneous
• Musculocutaneous
• Muscle
• Osteocutaneous
• Osteomusculocutaneous
• Omentum/Bowel

24. 3. Flaps
Accoding blood supply
• Type 1: a single major pedicle
• Type 2: one major pedicle and minor pedicles
• Type 3: two major pedicles
• Type 4: several segmental pedicles of approximately the same size
• Type 5: one dominant pedicle and secondary segmental pedicles.

27. 4. Local flap
• Advancement flaps of variable design
are moved or advanced in the direction
of their long axis directly into the
neighboring defect by simply stretching
the skin.
• There is no rotational or lateral
movement.
• direct wound closure after
subcutaneous mobilization
• single-pedicle advancement flap
• V-Y advancement flap

28. 4. Local flap
• Rotation flaps are semicircular in
design and rotate about a pivot point
into the adjacent defect needing to
be closed

29. 4. Local flap
• A transposition flap is transferred
about a pivot point in a lateral direction
into the adjacent defect.
• The flap must be planned larger and
longer than the defect needing to be
covered.
• The resulting tissue defect at the donor
site may be closed by direct suture. In
case of extensive tension, this defect
may also be covered by skin graft.

30. 5. Regional flap
• Regional flaps are characterized by a pedicle that remains in continuity with the
tissue defect while the transferred tissue originates from the same extremity
• The following factors will strongly influence the outcome of the flap:
❑The general condition of the patient (age, health risks, comorbidities, etc)
❑The local vascular status of the patient (comorbidities, etc)
❑The mechanism and energy of the trauma, ie, the visible extent of the injury as
well as the invisible zone of injury, which is usually less evident or even hidden
❑A careful clinical evaluation of the regional vascular perfusion in the area of
interest using different imaging techniques

31. 5. Regional flap : Fasciocutaneous flaps
Distally based sural flap
Anatomy and blood supply:
The superficial sural artery and the fibular artery.
Indication and landmarks
The distally based sural flap has a wide arc of
rotation that easily reaches:
• the distal third of the lower leg
• both malleoli
• the posterior aspect and the weight-bearing area
of the heel
• the dorsum of the foot

33. Distally based sural flap

34. Distally based sural flap
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35. Distally based sural flap

36. Distally based sural flap

37. 5. Regional flap : Fasciocutaneous flaps
Lateral supramalleolar flap
Anatomy and blood supply:
The fibular and the anterior tibial artery
Indication and landmarks
The reach of the flap includes the
anteromedial aspect of the lower leg and
the medial malleolus (transposition flap),
the dorsum, the medial and the lateral
aspect of the foot as well as the area of the
Achilles tendon and the heel (island flap)

38. Lateral supramalleolar flap

39. Lateral supramalleolar flap

40. 5. Regional flap : Muscle flap
Muscle flaps Gastrocnemius flap—medial head
Anatomy and blood supply:
Gastrocnemius myocutaneous flap was originally described in 1977,3 for providing
coverage over the knee region.
The medial head is longer and, thus, more often used as a flap than the lateral head.
The corresponding skin territory covering the muscles is ~23 cm long and 10 cm wide
.The medial head is about 15–20 cm long, 8 cm wide and 2–3 cm thick.
The medial sural artery (4–5 cm long; 2–2.5 mm in diameter) arises from the popliteal
artery 1–2 cm proximal to the knee joint.
Venous drainage is provided by paired concomitant veins that travel with the artery and
drain into the popliteal vein.

41. 5. Regional flap : Muscle flap
Muscle flaps Gastrocnemius flap—
medial head
Indication and landmarks
The anterior and medial aspect of the
knee.
The proximal third of the lower leg,
and the popliteal fossa

44. 5. Regional flap : Muscle flap
Muscle flaps Gastrocnemius flap—lateral head
Anatomy and blood supply:
The lateral head of the gastrocnemius muscle originates at the lateral condyle of
the femur. It is 12–17 cm long, 6 cm wide, and 2–3 cm thick.
The lateral sural artery (4–5 cm in length; 2–2.5 mm in diameter) arises from the
popliteal artery 1–2 cm proximal to the knee joint
Venous drainage is provided by paired concomitant veins that run with the artery
and drain into the popliteal vein.

45. 5. Regional flap : Muscle flap
•Muscle flaps Gastrocnemius
flap—lateral head
•Indication and landmarks
•The area of the popliteal fossa
•The anterolateral aspect of the
proximal third of the lower leg.

46. 6. Free flap
A free flap is a piece of tissue that is disconnected from its’ original blood supply,
and is moved a significant distance to be reconnected to a new blood supply.
Customized free flaps are more versatile and can be optimally adapted to a defect in
comparison to local or regional pedicled flaps if available at all.
Whether it is preferable to use fasciocutaneous tissue instead of muscular tissue,
particularly in regard to contaminated or infected traumatic wounds, is still a matter
of debate.

47. 6. Free flap - ALT
ALT:

48. 6. Free flap - musculocutaneous latissimus dorsi

49. The lower limb can be divided into 5 zones to facilitate choosing the best method
for coverage: thigh, knee, middle leg, lower leg, and foot and ankle.
Classic reconstructive armamentarium suggests the use of local muscle flap for the
upper two-third of the leg and free tissue transfers for the distal leg and foot.
ALGORITHM FOR LOWER LIMB DEFECTS