Chapter 111 - Lower extremity amputations - introduction

Question 1

What percentage of amputations as associated with diabetes

Answer 1

25-90%

Question 2

Risk of amputation in diabetes

Answer 2

8x 1) neuropathy 2) infection 3) PAD

Question 3

association in number of vascular surgeon and amputations

Answer 3

0.3 increase per 10000 = 1.6% reduction in amputation

Question 4

Indication for amputation

Answer 4

1) acute ischemia 2) chronic ischemia 3) foot infection 4) trauma 5) malignancy

Question 5

Indications for amputation by vascular surgeon

Answer 5

1) CLI with failed revasc 39% 2) extensive pedal gangrene 15% 3) non-reconstructable anatomy 11% 4) overwhelming pedal sepsis 9% 5) excessive surgical risk 9% 6) nonviable acute ischemia 8% 7) nonambulatory status 8%

Question 6

WIfI scoring system categories

Answer 6

Wound Infection foot Ischemia

Question 7

Delay to vascular surgery consultation for pedal tissue loss and rest pain

Answer 7

Tissue loss 73 days Rest pain 27 days

Question 8

Current practice predictors for choosing amputation over revasc for CLTI

Answer 8

1) dm 2) esrd 3) tissue loss 4) poor functional status

Question 9

5 perioperative stages to an amputation

Answer 9

Stage 1: pre-op decision to amputate; pre-op workup; surgeon in charge Stage 2: acute post-op 3-10 days; transition of care to rehab Stage 3: immediate post acute hospital; 4-8 weeks after surgery, recovery, wound heal, early rehab Stage 4: intermediate recovery; transition to first formal prosthetic device, begin ambulation; 4-6 months from healing date Stage 5: transition to stable stage; healing continues for 12-18 months after initial healing; visit prosthetist until 1 year of stability; move towards social reintegration

Question 10

Mortality of major amputation

Answer 10

8% AKA may have double that of BKA

Question 11

Complications following major amputation

Answer 11

1) stump complication 10% 2) CAD, VTE, CVA 0.5-2.1%

Question 12

% of amputation-related death caused by PE

Answer 12

17%

Question 13

Urgent amputation options

Answer 13

1) guillotine amputation 2) cryoamputation

Question 14

Techniques of cryoamputation

Answer 14

1) dry ice 2) plastic bag 3) umbilical tape as tourniquet 4) towel blanket adhesive tape 5) heating pad can be maintained for weeks

Question 15

Goals of amputation

Answer 15

1) eliminate infected, necrotic and painful tissue 2) to achieve uncomplicated wound healing 3) to have appropriate remnant stump to accommodate prosthesis

Question 16

Extra energy expenditure required to ambulate after unilateral BKA and AKA

Answer 16

BKA 10-40% AKA 50-70% TABLE 111.3

Question 17

Prosthetic use rate after BKA and AKA

Answer 17

BKA 50-100% AKA 10-30%

Question 18

Rate of revising BKA to AKA

Answer 18

15-25%

Question 19

Mortality in revising BKA to AKA

Answer 19

5%

Question 20

Healing rate of BKA

Answer 20

80%

Question 21

Healing rate of AKA

Answer 21

90%

Question 22

Healing rate of BKA with palpable popliteal

Answer 22

~100%

Question 23

Skin temperature to predict amputation heal rate

Answer 23

Amputation level skin > 90F has 80-90% chance of healing

Question 24

Absolute ankle pressure to predict healing of BKA

Answer 24

ankle pressure > 60 = 50-90% healing of BKA

Question 25

risk of needing amputation with an ABI > or < 0.5 in CLTI with wound

Answer 25

< 0.5: 28% 6 month, 34% 1 year > 0.5: 10% 6 month, 15% 1 year

Question 26

Toe pressure that predict failure of minor amputation in diabetics

Answer 26

< 38 mmHg

Question 27

Other methods of assessing amputatin healing likelihood

Answer 27

1) radioisotope scan 2) scintigraphy 3) skin perfusion presure 4) transcutaneous oxygen measurement (best)

Question 28

Accuracy of transcutaneous oxygen

Answer 28

87-100% at prediction of wound healing failure when tcPO2 < 30 mmHg

Question 29

Prediction of wound healing by non-invasive vascular studies

Answer 29

TABLE 111.2

Question 30

Factors associated with poor ambulation postop

Answer 30

1) poor preop ambulation 2) age > 70 3) dementia 4) ESRD 5) CAD

Question 31

Dressing types after BKA

Answer 31

1) soft gauze dressing with elastic wrap 2) thigh level rigid plaster 3) thigh level plaster with immediate postop prosthesis (IPOP) 4) short removable rigid plaster 5) prefabricated pneumatic IPOP IPOP may reduce rehab time not clear about post-op complication

Question 32

Timing of NWB on stump after BKA

Answer 32

4-6 weeks

Question 33

Types of AKA prosthetics

Answer 33

1) standard 2) intelligent prostheses with microprocessor

Question 34

BKA prosthetics

Answer 34

1) standard passive ankle 2) energy conserving ankle 3) open type socket

Question 35

Predictors of death: patients with AKA who were not ambulating pre-op

Answer 35

10x no prosthesis 2x mortality at 1 year

Question 36

through knee amputation key points

Answer 36

1) need adequate residual skin and subcutaneous tissue 2) higher normal and max walking speed with lower energy expenditure than AKA 3) earlier weight bearing status with lower risk of wound complication than BKA

Question 37

ambulation status for age < 60 and well-controlled comorbidities

Answer 37

if walking before post op ambulation 70% survival 80% independent living 90% at 1 year

Question 38

Chance of controlateral limb amputation in 5 years in diabetic

Answer 38

15-35% higher risk if ESRD