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
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
Timing
Al-Hourani et al, J Orthop Trauma 2023
- retrospective review 373 type IIIB open tibias
- >2d between fix and flap increased infection rates by 55%
- >5d increased rates 64%