59: Lower Extremity Amputations - Bennett

Question 1

considerations for successful limb salvage

Answer 1

1. ensure good blood flow
2. control infection
3. aim for good biomechanical result
4. create a stable soft tissue envelope (healing and protection)

Question 2

timing of surgery after vascular intervention

Answer 2

4-10 days after a bypass

10-30 days after an angioplasty

Question 3

should you stop plavix, etc ?

Answer 3

typically keep patients on (after bypass, angioplasty)

also depends on level of amputation

Question 4

what is an angiosome?

how many in the foot?

Answer 4

• Angiosomes: composite vascular territories providing blood supply to skin, nerves, muscle, tendon, and bone
• foot is divided into 6 angiosomes (40 total in body)
  
  • post tib a. = 3 angiosomes
    
    • calcaneal branchsupplies the medial ankle and lateral plantar heel
    • medial branch that feeds the medial plantar instep
    • lateral branch that supplies the lateral forefoot, plantar midfoot, and entire plantar forefoot
  • ant tib a = 1 angiosome
  • peroneal a = 2 angiosome
    
    • supplies the lateral ankle and plantar heel via the calcaneal branch and the anterior upper ankle via an anterior branch

Question 5

if the pt is not ambulatory, what amputation might be better?

Answer 5

BKA or AKA

but even if pt not ambulatory, maintaining limb can be advantageous for transfers

Question 6

anesthesiology class 1-5 patients

Answer 6

Class 1 patients have no medical problems, other than the pathologic condition associated with the surgery, no diabetic patient will fit this category.

Class 2 patients have a stable, chronic medical problem that is well controlled such as stable diabetes.

Class 3 patients are more seriously ill, with unstable medical problems, and are more likely to need intensive, or at least close, medical supervision in the perioperative period.

Class 4 patients are very seriously ill, perhaps at risk for septic shock, or other major cardiovascular complications and definitely require intensive perioperative care.

Class 5 patients are not expected to survive surgery or the perioperative period.

Question 7

where is toe amputation performed?

Answer 7

• through the base of proximal phalanx
• trying to maintain intrinsic musculature
• resection at proximal metaphysis allows for closure over raw cancellous bone - area that is better vascularized than the cartilage of the met head
• skin incisions made with medial and lateral flaps fashioned around base of digit “fish mouth”

Question 8

define ray resection

Answer 8

amputation of a digit and most, or all, of its associated metatarsal

• excellent procedure for drainage of an acute infection
• pefromed in presence of abscess or osteomyelitis of toe and MTP jt
• extensive necrosis of skin, soft tissue, or bone in the involved digit may necessitate ray resection to obtain adequate viable skin for closure

Question 9

indications for metatarsal amputation

Answer 9

• Gangrene of one or more toes, provided the gangrene has stabilized and does not involve the dorsal or plantar aspect of the foot
• Stabilized infection or open wound of the distal portion of the foot
• An open infected lesion in a neuropathic foot
• Extension of an infectious process to the web space or plantar aspect of the foot is an indication for an open transmetatarsal amputation. (This may be closed at a later time or allowed to heal by second intention.)
• This amputation maybe performed at any level of the metatarsals, provided the insertion of the tibialis anterior tendon is preserved.
• Preservation of the tendon cannot be overemphasized as loss of function will result in an equinus deformity. (also do gastroc resection w/ amputation)

Question 10

what is a lisfranc’s disarticulation?

Answer 10

amputation at the tarsometatarsal joint

Question 11

disarticulation at talonavicular and calcaneal cuboid jt

Answer 11

choparts amputation

Question 12

boyd’s amputation

Answer 12

tibial calcaneal fusion

modified boyd’s = use talus as interposition bone graft if viable

Question 13

pirogoff amputation

Answer 13

tibial calcaneal fusion

calcaneus is positioned vertical to help alleviate LL discrepancy

Question 14

full ankle disarticulation

Answer 14

symes amputation

Question 15

how much blood should you have prepared for amputation pt?

Answer 15

at least 2 untis of blood available

check hemaglobin and hematocrit

expect blood loss

do not use tourniquet

Question 16

calcanectomy

Answer 16

• partial or complete removal of calcaneus
• advantageous for lg heel ulcers with calcaneal osteomyelitis and stable midfoot and forefoot