Amputations

Indications

  • Dead: ischaemia (atherosclerosis), gangrene, infection (clostridium), trauma
  • Deadly: tumours of bone (osteosarcoma) / soft tissue (malignant melanoma)
  • Dead weight (excess fingers/toes)

Aim is to produce most practical/functional limb for prosthetics - therefore through knee (Gritti-stokes) are not favoured.
Through knee - when previous orthopaedic surgery precludes it (ie, long intramedullary femoral nail)

 

Can be performed under GA / LA
Double check side of operation
Isolate areas of gangrene
Generous flaps can be trimmed later
If tissue does not bleed (it will not heal properly) - therefore move proximally with amputation
Mobilise early to avoid contractures

 

Workup

  1. Patient
    • Condition and mobility of patient (AKA more easy to transfer bed-bound patient)
    • Ability for patient to be rehabilitated
    • Psychological counselling
  2. Disease
    • Pathology / severity of disease
    • Viability of flaps
  3. Health-care related
    • OT / Physiotherapy
    • Limb fitting / prosthetics (end-bearing amputation may be suitable to allow simple prosthesis)

Deciding level of amputation

  1. Joint contractures - AKA
  2. Severely reduced mobility - AKA affords better transfer, less risk of stump pressure sores
  3. Knee OA - AKA
  4. Infection
  5. Viability of distal limb 

Types of Amputation

  1. Upper limb
    • Upper arm
    • Supracondylar (above elbow)
    • Extraarticulation (thorugh elbow)
    • Proximal forearm (below elbow)
    • Distal forearm
    • Wrist
    • Metacarpophalangeal
    • Proximal interphalangeal
    • Distal interphalangeal
  2. Lower limb
    • Hindquarter
    • Above knee - equal anterior-posterior flap
    • Supracondylar
    • Through knee (Gritti-stokes)
    • Below knee - long posterior flap
    • Symes (Tibia/Talus)
    • Chopart (Talus/Navicular)
    • Lisfranc (Navicular/Metatarsal) - posterior plantar flap
    • Transmetatarsal
    • Ray

Above knee amputation

  • One hand's breadth (8-10cm) above upper border or patella: site of femur division
  • Equal length flaps
  1. Divide skin + tissues along planned lines
  2. Divide soft tissue
    • Ligate veins using2/O absorbable suture
    • Deepen incision to bone
    • Divide quadriceps tendon (to patella)
    • Divide hamstrings posteriorly
    • Double-Ligate femoral artery
    • Apply tension to nerves before ligating so they retract (femoral/sciatic)
    • Retract thigh muscles
  3. Divide Bone
    • Divide femur, remove lower leg, place clean towel under stsump
    • Smooth edges of femur using a rasp + bone wax (stop bleeding)
  4. Close defect
    • Bring anterior-posterior muscles together using 1/O interrupted sutures
    • Place suction drain under muscle layer
    • Place second layer of sutures in superfical muscles
    • Suture skin edges with interrupted 2/O sutures
  5. Cover stump with gauze + crepe bandage

 

Below knee amputation

  • 14cm from tibial plateau: tibial division / 12cm from tibial plateau: fibular division 2cm proximal
  • Burgess Long posterior myocutaneous gastrocnemius flap (extending down to achilles tendon)
  • Robinson skew flap when posterior flap area compromised
  1. Incise along marked lines
  2. Divide soft tissue
    • Divide achilles tendon posteriorly
    • Divide posterior muscles
    • Ligate vessels, divide (ie. don't tie them) nerves
  3. Divide Bone
    • Cut fibula obliquely (with Gigli saw) + divide tibia 2cm distal to this
    • Clear muscle off bone with periosteal elevator
  4. Close defects
    • Oppose muscle flaps + suture
    • Unite skin edges with 2/O interrupted
    • Trim edges
  5. Apply crepe/cotton-wool bandaging

Allows for pressure to be put on stump with smaller risk of dehiscence

 

Complications

  1. Early
    • Haematoma
    • Wound infection
    • Dehiscence, flap necrosis
    • DVT / PE
    • Phantom limb pain
  2. Late
    • Neuroma
    • Bone spurs
    • Stump ulceration
    • Psychological distress