Amputation (upper limb, above-knee, below knee)

Question 1

What is the most common cause of non-traumatic limb amputation?

Answer 1

Diabetes

Question 2

What are the indications for amputation?

Answer 2

3 D’s i.e. when tissue is:
* Dead or dying - peripheral vascular disease, severe trauma, burns or frostbite
* Dangerous - limb harbours a malignant tumour, lethal sepsis i.e. gas gangrene or because of a possible crush syndrome
* Damn nuisance - pain, gross malformation, severe loss of function, recurrent sepsis

Question 3

How is a suitable level of amputation determined?

Answer 3

Site of vessel occlusion
Fitting of prosthesis e.g. preservation of knee

Question 4

How is an above knee amuptation done?

Answer 4

• 22-25cm below the greater trochanter
• myoplastic flap is used
• bone amputated at the level proximal to that of the muscle and skin
• muscle is sutured over exposed bone
• skin flaps are then closed over the muscle

Question 5

How is a below knee amputation done?

Answer 5

• 10-12cm below the tibial tuberosity
• long posterior flap of muscle and skin is wrapped forward over the amputated bone and sutured in place

Question 6

How is a foot/mid foot amputation done?

Answer 6

Foot (Syme’s amputation) - malleoli are cut level with the inferior surface of the tibia, skin pad is from the heel pad to create a weight bearing stump

Mid-foot- the amputation is made at mid-tarsal level

Question 7

How is a toe amputation done?

Answer 7

Toe is removed with all or part of the proximal phalanx
Dorsal or ventral skin flaps are sutured together over the bone

Question 8

What are the complications of amputation?

Answer 8

Early
* breakdown of skin due to ischaemia or tight suturing
* gas gangrene - in high above knee amputations

Late
* poor circulation -> blue stump -> ulceration -> reamputation
* cut nerves causing painful tender nerve bulbs
* phantom limb sensations - eventually disappear