Amputation

• Patients with nonviable extremities should undergo prompt amputation.
• Site of amputation depends on extent of viable tissue capable of healing

• Prefer below-knee amputation – because better mobility after surgery
• Above-knee amputation→better stump healing, but poorer mobility

• Delays in amputation of a nonviable extremity can result in infection, myoglobinuria, acute renal failure, and hyperkalemia
• In pts with chronic critical limb ischaemia:

• 5% pts require amputation as initial therapy
• majority require amputation within 5 years
• Intermittent claudication – amputation in 5% pts within 5 years, 10 % within 10 years

• Indications 

1. Vascular(PVD, Burgers, AV fistulae)
2. Infection(Osteomyelitis, Gas gangrene, Nec Fasciitis)
3. Trauma(burns, frostbite)
4. Malignancy

• Complications:

1. Operation mortality is 20%
2. On year survival is 50%
3. Can be divided into specific/general; immediate/late

Specific early

1. Psychological and social implications
2. Haematoma and wound infections
3. DVT and PE
4. Phantom limb pain – due to sensory cortex believing the limb is still present
5. Skin necrosis (due to poor perfusion of the stump)

Specific late:

1. Osteomyelitis(infection transmitted through the stump)
2. Stump ulceration – can be caused by pressure from prosthesis
3. Stump neuroma – swelling of the distal nerve as it tries to regrow following division
4. Fixed flexioin deformity of the knew
5. Difficulty in mobilizing
6. Spurs and osteophytes in underlying bone