Relative anatomy

Anterior = Extensor compartment
- Tibialis anterior, EHL, EDL
- Deep peroneal nerve
  - Lies on interosseous membrane lateral to ATA
  - Supplies the muscles above + a small area of skin at 1st web-space
- Anterior tibial artery
  - From popliteal bifurcation, via interosseous membrane at neck of fibula
  - Has two companion veins on either side
Lateral
- Peroneus longus, peroneus brevis
- Superficial peroneal nerve - Supplies those two muscles + sensation to dorsum of
- foot
Posterior Superficial
- Gastrocnemius , soleus (soleus deep)
Posterior Deep
- Tibialis posterior, FHL, FDL
- Tibial nerve
- Deep to soleus, PTA crosses from lateral to medial
  - Supplies all the muscles of flexor compartment
- Posterior tibial artery
  - Runs down on Tibialis posterior between the two flexor
  - Also has paired veins
  - Gives of the peroneal branch 2.5cm distal to popliteus

Key principles

This describes the Long Posterior Myocutaneous Flap (Burgess Technique)
- Longer posterior flap than Above knee amputation
- Alternative is the Skew Flap
Skin – thick, no tension
Muscle – good bone cover
Nerves – cut under tension
Bones – bevel & smooth
- Optimal tibial section is 1/3 of its length

GA/Spinal
Prep/ drape – leg free draped, foot wrapped
Incision
- Anterior skin incision 12cm below tuberosity – 1/3 calf circumference then
- Down vertical axis for about 1.5x the length of transverse incision
- Posterior flap the created with a transversely posterior incision
- Incise down through deep fascia ligating LSV
Anterior and lateral compartment
- Scalpel dissection to expose tibia and fibula at the same level as the anterior incision
  - Anterior
    - Anterior tibial artery and vein identified and ligated centrally in the anterior compartment
    - Deep peroneal nerve transected under tension
  - Lateral
    - Superficial perineal nerve
Bone
- Elevate periosteum
- Divide fibula as high as possible with bone cutters
  - Take fibula first – if take tibia first the fibula can shatter
- Divide tibial– bevel & smooth end
Posterior compartment
- Posterior compartment muscles are then divided obliquely to create a posterior muscle flap
- Ligate posterior tibial artery & vein
- Ligate & divide posterior tibial nerve under tension
- Ligate the peroneal artery
Flap
- Fashion posterior flap on fascia overlying gastrocnemius, debulk soleus medially and laterally
- Suture gastrocnemius fascia to pretibial fascia with 1/0 vicryl
Drain
Subcuticular monocryl
Softban & crepe bandage