Skin Cover Options

Basic Concepts

 

Proximal tibia

- gastrocnemius local muscle flap

- gracilis free muscle flap if gastroc damaged

 

Middle tibia

- soleus local muscle flap

- gracilis free muscle flap

 

Distal tibia

- posterior tibial fasciocutaneous local flap

- gracilis free muscle flap

 

Distal Tibia Skin Graft

 

Hip / Thigh

- TFL musculocutaneous local flap

 

Heel

- FHB / Abductor Hallucis Longus

- dorsalis pedis fasciocutaneous local island flap

- gracilis free muscle flap

 

Types of coverage

 

1.  Split skin grafts

 

2.  Local flaps

- muscle (gastrocneumius / soleus / T Anterior / EDB)

- musculocutaneous (gastroc / TFL)

- fasciocutaneous (dorsalis pedis /

 

3.  Free flaps

- muscle

- fasciocutaneous

 

1.  SSG

 

Indication

- on bed of healthy muscle

- must not be infected

 

Technique

- graft taken with harvestor

- set desired thickness

- usually from anterior thigh

- meshing increase coverage

- stitched to rim of wound

- pressure dressing applied

- takes 5 - 7 days to take

 

2.  Local Flaps

 

A.  Muscle Flaps 

 

Advantage 

- high blood supply 

- deliver ABx to fight infection

- excellent bulk for eliminating dead space

 

Types

 

Type 1 

- single pedicle, easiest to transfer

- tensor fascia lata, gastrocnemius

 

Type 2 

- one or more dominant pedicles, plus minor pedicles

- soleus

 

Type 3 

- 2 dominant pedicles

 

Concepts

 

The muscle flap mobilises about the vascular pedicle, not the muscle itself

 

Preserving the neuro pedicle can be disadvantageous

- muscle twitching can compromise the flap

- however this can be advantageous i.e. in bracial plexus surgery

 

These never have an independent blood supply and are always dependent on the pedicle

- can raise the flap

- must be aware of and preserve pedicle

- check old notes

- plastics review

- ultrasound

 

Gastrocnemius flaps

 

Types

 

Lateral and medial

- Workhorse of the leg

- Cover between the knee prox tibia

- Need to check sufficient muscle bulk and that muscle has not been damaged in accident

 

Medial 

- most commonly used

- close to anterior tibia & larger

 

Lateral 

- can use, but must remove fibula and tunnel under anterior compartment

- putts pedicle at risk

 

Blood supply

- each head is supplied by a single sural artery 

- branch of the popliteal artery just below the joint line

- need only do angio if severe trauma, knee dislocation or previous vascular procedure

 

Soleus

 

Type 2 flap

- Useful for the middle third of the tibia

- More difficult to raise as must beware the posterior tibial artery

- Muscles can easily be damaged by the tibia in high velocity trauma

 

Tibialis Anterior 

 

Occasionally used if not too damaged

 

EDB

 

Local to ankle

 

B.  Musculocutaneous flap

 

Definition

- skin is taken also to extend the flap

- SSG used to cover skin defect of donor site

- Gastrocenumius / TLF

 

TFL

- TFL, skin and deep fascia

- Pedicle is branch of lateral femoral circumflex

- Used for hip and thigh

- Need SSG to skin defect

 

C.  Fasciocutaneous flap

 

These have independent blood supply after 2 weeks

 

Posterior tibial artery flap

- Distal Tibia but greater than 10 cm from ankle

- Based on Great saphenous vein for drainage

 

Dorsalis Pedis Island Flap

- Used to cover heel

 

Sural artery flap

 

3.  Free Flaps
 

Concept

- taking tissue with vascular pedicle 

- transferring it to a distal site and re-anastomosing it

- select flaps that have a long pedicle for ease of reimplantation and positioning

 

Results

- 95 - 98% success with good surgeons

- Nil evidence that smoking or age affect flap

- CRF / DM / atherosclerosis do

 

A. Muscle

 

For when muscle is required to bony cover or to fill dead space

 

Gracilis

- For defects 10 - 15 cm

- Based on medial circumflex artery

- Reasonable thin

 

Latissmus dorsi

- Workhorse

- For larger defects up to 25 x 40 cm 

- Based on thoracodorsal artery

 

Rectus Abdominus

- Less commonly used as hernias are a problem

 

Serratus anterior

- Used for small defects

 

B. Fasciocutaneous

 

For when skin cover only is required, not muscle bulk i.e. over ankle joint

 

Radial free flap

- Workhorse flap