PREVENTION OF DIABETIC FOOT ULCERS
AND LOWER EXTREMITY AMPUTATION
Barry Stults, M.D.
Scott Clark, D.P.M
Thomas Miller, M.D.
University of Utah Medical Center
©2006. American College of Physicians. All Rights Reserved.
CASE: Mr. M.C.
• 64 yr-old obese white male, not seen x 12 mo
• Type 2 DM (15 yrs)
BP 
(18 yrs)
Dyslipidemia (18 yrs)
CABG
(10 yrs ago)
Claudication (today; 25 yds)
• Insulin/Metformin/Statin/ARB/Hctz/CCB/ASA
• “Sore on my left foot, Doc”
©2006. American College of Physicians. All Rights Reserved.
CASE: Mr. M.C.
• Clinical evaluation of heel ulcer:
– Probe reached bone
– Extensive subcutaneous abscess
• MRI: extensive osteomyelitis
• ABI: 0.2
• Angiography: severe infrapopliteal, suprapopliteal obstruction
– Not amenable to revascularization
• Uncontrolled infection despite antibiotics/drainage
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
AMPUTATIONS IN DIABETES
Common:
• Worldwide – amputation 2 to diabetes q 30 sec.
• U.S.A. – 80,000 amputations/y (2002)
– Higher rates in men, racial/ethnic minorities
Costly:
• $60,000/amputation
• $2 billion/y total costs
Lancet 2005; 366:1719
Diabetes Care 2004; 27:1598
Diabetes Care 2003;
26:495
©2006. American College of Physicians. All Rights Reserved.
AMPUTATIONS IN DIABETES
Tragic: “Rule of 50”
• 50% of amputations
transfemoral/transtibial level
• 50% of patients
2nd amputation in  5y
• 50% of patients
Die in  5y
Clinical Care of the Diabetic Foot, 2005
©2006. American College of Physicians. All Rights Reserved.
FOOT ULCERS IN DIABETES
Precipitate 85% of amputations: “Rule of 15”
• 15% of diabetes patients
Foot ulcer in lifetime
• 15% of foot ulcers
Osteomyelitis
• 15% of foot ulcers
Amputation
Clinical Care of the Diabetic Foot, 2005
©2006. American College of Physicians. All Rights Reserved.
FOOT ULCERS IN DIABETES
Costly:
• $30,000/ulcer
• $9 billion/y total costs
Tragic:
• Quality of life: ulcer patient  amputation patient
– Burden of non-weight-bearing as ulcer heals
– Lifetime behavioral adaptations to prevent recurrence
– Fear of recurrent ulcer/amputation
• 70% ulcer recurrence in  3y
Foot Ankle Int 2005; 26:32, 128
Clin Infect Dis 2004; 39(Suppl 2):S129
©2006. American College of Physicians. All Rights Reserved.
TEAM CARE REDUCES ULCERS/AMPUTATIONS
Five clinical trials:
• Format: integrated, risk-stratified interventions
– ID high-risk patients with exam:
•
•
•
•
Frequent follow-up to detect early problems
Educate/motivate self-care behaviors
Prophylactic nail/skin care by podiatry
Therapeutic footwear, if needed
– Prompt, multidisciplinary Rx of ulcers
Lancet 2005; 366:1676
©2006. American College of Physicians. All Rights Reserved.
TEAM CARE REDUCES ULCERS/AMPUTATIONS
Efficacy of team care:
– 50-80% reductions in ulcers/amputations
• Economic modeling studies of team care:
– Cost-effective if 25-40% reduction in ulcer rate
– Cost-saving if > 40% reduction in ulcer rate
Applicable only to high-risk patients
Lancet 2005; 366:1719
Diabetes Care 2004; 27:901
©2006. American College of Physicians. All Rights Reserved.
PATHOGENESIS OF DIABETIC FOOT ULCER AND AMPUTATION
Sensory
 Joint
Neuropathy Mobility
Motor
Neuropathy
Autonomic
Neuropathy
Protective
sensation
Muscle atrophy and
2° foot deformities
 Sweating
2° dry skin
Ischemia
Foot pressure
Minor trauma
recognition
 Foot pressure
esp. over
bony prominences
Fissure
 Healing
Callus
Pre-ulcer
ULCER
Minor Trauma:
Mechanical
Chemical
Thermal
PAD
Infection
AMPUTATION
Interdigital Maceration
(Moisture, Fungus)
©2006. American College of Physicians. All Rights Reserved.
OTHER RISKS FOR ULCER/AMPUTATION
Failure to adequately care for the feet:
– Inadequate patient education
– Inadequate patient motivation
• Depression, anxiety, anger more common in diabetes
– Physical disability
• Cannot see feet 2 to retinopathy
• Cannot reach feet 2 to obesity, age (?50% of patients)
– Limited access to podiatry services
Age Ageing 1992; 21:333
Diabetes Care 2003; 29:495
Diab Metab Res Rev 2004; 20(Suppl 1):S13
©2006. American College of Physicians. All Rights Reserved.
CAUSAL PATHWAYS FOR FOOT ULCERS
NEUROPATHY

DEFORMITY

MINOR TRAUMA
- Mechanical (shoes)
- Thermal
- Chemical
% Causal Pathways
Neuropathy:
78%
Minor trauma:
79%
Deformity:
63%
Behavioral issues
?
POOR SELFFOOT CARE
ULCER
Diabetes Care 1999; 22:157
©2006. American College of Physicians. All Rights Reserved.
DETECTING FEET-AT-RISK
• History:
– Prior amputation
– Prior foot ulcer
– PAD: known or claudication at < 1 block
• Exam:
– Insensate to 5.07/10g monofilament
– Major foot deformities
– PAD
• Absent DP and PT pulses
• Prolonged venous filling time
• Reduced Ankle-Brachial Index (ABI)
– Pre-ulcerative cutaneous pathology
Arch Intern Med 1998; 158:157
©2006. American College of Physicians. All Rights Reserved.
RISK STRATIFY FOR FOOT ULCERATION
Foot Ulcer,
%/yr
28.1%
18.6%
Risk Level
3: prior amputation
prior ulcer
% Office Patients
(diabetes clinics)
7%
2: insensate
and
foot deformity
or
absent pedal pulses
6.3%
10%
1: insensate
4.8%
17 - 30%
0: all normal
1.7%
66%
Diabetes Care 2001; 24:1442
Diabetes Metab 2003; 29:261
©2006. American College of Physicians. All Rights Reserved.
ANNUAL DIABETIC FOOT EXAMS
2000 Behavioral Risk Factor Surveillance System, CDC
% with foot
exam in
past year
Total
63
Private MedicaidInsurance Medicare
64
65
VA
84*
Uninsured
48*
*p < 0.01
Health Services Research 2005; 40:361
©2006. American College of Physicians. All Rights Reserved.
PHYSICAL EXAMINATION OF THE FEET
IN PERSONS WITH DIABETES
©2006. American College of Physicians. All Rights Reserved.
SENSORY NEUROPATHY IN DIABETES
• Loss of protective sensation in feet
– Sensory loss sufficient to allow painless skin injury
• Major risk factor for foot ulcer in diabetes
• Detect with 5.07/10g Semmes-Weinstein monofilament
– Prevalence of insensate feet to 10g monofilament:
• Age > 40y: 30% of diabetic patients
• Age > 60y: 50% of diabetic patients
• Up to 50% have no neuropathic symptoms
Diabetes Care 2006; 29(Suppl 1):S24
Diabetes Care 2004; 27:1591
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
UTILITY OF MONOFILAMENT TESTING
Predicts ulcer/amputation in 5 prospective studies:
• NPV (normal sensing) = 90-98%
PPV (fail to sense) = 18-36%
• Prospective 32 mo observational study:
– 80% of ulcers/100% of amputations in insensate feet
• Superior predictive value to other tests:
– Pin prick, cotton wisp, symptoms
– ? 128 Hz tuning fork?
• ADA recommendation, 2006: also test vibration
Diabetes Care 2006; 29(Suppl 1):S25
J Fam Pract 2000; 49:S30
Diabetes Care 1992; 15:1386
©2006. American College of Physicians. All Rights Reserved.
USING THE 5.07/10gm MF (Tool-Kit)
• Demonstrate sensation on
the forearm or hand
• Place monofilament
perpendicular to test site
• Bow into C-shape for one
second
• Test four sites/foot: Predicts
95% of ulcer formers vs. 8
sites
• Heel testing does not
discriminate ulcer formers
• Avoid calluses, scars, and
ulcers
©2006. American College of Physicians. All Rights Reserved.
USING THE 5.07/10g MF (Tool-Kit)
• Minimize bias:
– Test sites in random sequences
– Test each site X3, sham test as 1 of 3
•
•
•
•
•
•
Do you feel it? Yes or No?
Retest site if patient fails (misses 2/3 responses)
Insensate at 1 site = insensate feet
Falsely insensate with edema, cold feet
Test annually when sensation normal
Use < 100x/d; replace if bent; replace q 3 mo.
• Purchase calibrated MF (See Tool-Kit)
©2006. American College of Physicians. All Rights Reserved.
PAD IN DIABETES
• Prevalence (ABI < 0.9): 20-30%
– 10-20% in type 2 diabetes at Dx
– 30% in diabetics  age 50y
– 40-60% in diabetics with foot ulcer
• Complications:
– Claudication and functional disability
– Increases risk for concurrent CAD and CVD
– Delays ulcer healing
• Increases amputation risk
• Not increase foot ulcer risk
JACC 2006; 47:921
Diabet Med 2005; 22:1310
Diabetes Care 2003; 26:3333
©2006. American College of Physicians. All Rights Reserved.
HX TO DETECT PAD IN DIABETES
• Claudication at < 1 block suggests severe ischemia
Vascular Level
Site of Pain
Aorto-iliac
Buttocks/Thigh
Femoral
Calf
Tibioperoneal
Foot/Ankle
• Rest pain indicates critical ischemia
– Toes and forefoot
– Difficult to distinguish from neuropathic pain
©2006. American College of Physicians. All Rights Reserved.
HX TO DETECT PAD IN DIABETES
Ischemic Rest Pain
Unilateral (usually)
Continuous;  hs
 With dependency
Absent DP/PT pulses
Neuropathic Pain
Bilateral (usually)
Wax/wane
No change with dependency
Variable DP/PT pulses
(After Pompogelli and Campbell, 2002)
©2006. American College of Physicians. All Rights Reserved.
HX TO DETECT PAD IN DIABETES
• Asymptomatic, severe PAD common in diabetes
– Tibio-peroneal disease predominance:
• Unrecognized ankle/foot claudication
• No claudication
– Sensory neuropathy blunts/eliminates pain sensation of
claudication and rest pain
Diabetes Care 2003; 26:3333
©2006. American College of Physicians. All Rights Reserved.
EXAM TO DETECT PAD IN DIABETES
• Pedal pulse exam:
– Absent DP and PT: LR = 3.0-3.8 for severe PAD
– Absent DP or PT not predict PAD
• Non-palpable DP (8%) or PT (3%) in normals
– Present DP and PT not R/O PAD!
• 30% with PAD have one palpable pulse (collaterals)
• High PAD suspicion  vascular testing
– Claudication, foot ulcer
JAMA 2006; 295:536
Arch Intern Med 1998; 158:1357
Diabetes Care 2003; 26:3333
©2006. American College of Physicians. All Rights Reserved.
EXAM TO DETECT PAD IN DIABETES
• Venous filling time
– Technique:
• Sitting: ID pedal vein bulging above skin
• Supine: Elevate leg to 45° for 1 min
• Sitting:  time to pedal vein bulging above skin
J Clin Epidemiol 1997; 50:659
Arch Intern Med 1998; 158:1357
©2006. American College of Physicians. All Rights Reserved.
EXAM TO DETECT PAD IN DIABETES
• Venous filling time
– Filling time > 20 sec predicts ABI < 0.5
• Sensitivity = 22%; Specificity = 94%; LR = 3.9
J Clin Epidemiol 1997; 50:659
Arch Intern Med 1998; 158:1357
©2006. American College of Physicians. All Rights Reserved.
OTHER EXAM FINDINGS FOR PAD
• Helpful:
– Femoral bruit (LR = 4.7–5.7)
– Unilateral cool extremity
• Not predictive of PAD:
– Atrophic skin
– Hair loss
– Capillary refill > 5 sec
Diabetes Med 2005; 22:1310 Arch Intern Med 1998; 158:1357
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
VASCULAR LAB TO DETECT PAD
• Ankle/Brachial BP Index or ABI Testing
– Screening: 2004 ADA recommendation
• “Consider” at age 50 and q 5 yr
• Screen earlier if multiple CVD risks
– Diagnosis:
• Claudication, absent DP/PT pulses, foot ulcer
– Limitations:
• Underestimate severity if medial artery Ca++
• Consider pulse volume recording, systolic toe BP, vascular
consultation if uncertain about PAD
Diabetes Care 2005; 28:2206
Diabetes Care 2004; 27(Suppl 1): S15-S35
©2006. American College of Physicians. All Rights Reserved.
INTERPRETATION OF THE ABI
Normal
Mild obstruction
*Moderate obstruction
*Severe obstruction
**Poorly compressible
2° to medial Ca++
ABI
0.91-1.30
0.71-0.90
0.41-0.70
 0.40
>1.30
*Poor ulcer healing with ABI  0.50
**Further vascular evaluation needed
©2006. American College of Physicians. All Rights Reserved.
MOTOR NEUROPATHY AND FOOT DEFORMITIES
• Hammer toes
• Claw toes
• Prominent metatarsal heads
• Hallux valgus
• Collapsed plantar arch
©2006. American College of Physicians. All Rights Reserved.
•
Hammer
Toes
•
Claw Toes
From Levin and Pfeifer, The Uncomplicated Guide
to Diabetes Complications, 2002
©2006. American College of Physicians. All Rights Reserved.
Hallux
Valgus
From Levin and Pfeifer, The Uncomplicated
Guide to Diabetes Complications, 2002
©2006. American College of Physicians. All Rights Reserved.
From Boulton, et al Diabetic Medicine 1998, 15:508
©2006. American College of Physicians. All Rights Reserved.
PRE-ULCER CUTANEOUS PATHOLOGY
Neuropathy  inappropriate footwear:
– Persistent erythema after shoe removal
– Callus
– Callus with subcutaneous hemorrhage: “pre-ulcer”
Autonomic neuropathy and secondary dry skin:
– Fissure  ulceration
– Augment callus formation
Poor self-care of the feet:
– Interdigital maceration with fungal infection
– Nail pathology
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
RISK-STRATIFIED FOOTCARE
MANAGEMENT FOR DIABETES PATIENTS
©2006. American College of Physicians. All Rights Reserved.
LOW RISK: CATEGORY 0 PATIENTS
• Annual comprehensive foot examination
– Questionnaire completed by patient in waiting room
– Examination form with decision-support
(See Tool-Kit)
• Every visit visual inspection if higher risk
– Racial/ethnic minorities; alcoholism; homeless
• Basic education: self-management, appropriate
footwear
– Brief counseling
– Written handout
JAMA 2005; 293:217
©2006. American College of Physicians. All Rights Reserved.
HIGH RISK: CATEGORY 1-3 PATIENTS
• Annual comprehensive foot exam
• Inspect feet at every office visit
• Podiatry care stratified to risk level
• Intensive patient education
• Detect/manage barriers to foot care
• Therapeutic footwear, if needed
©2006. American College of Physicians. All Rights Reserved.
HIGH RISK: CATEGORY 1-3 PATIENTS
Nursing tasks to facilitate foot exams:
– “High Risk Feet” stickers to each chart (Tool-Kit)
– Remove patient’s shoes/socks
• Increases % of foot exams in observational studies
– Determine that patient can reach/see soles of feet
– Stock 10g monofilament in each room
• Consider training to perform 10g monofilament exam
– Provide patient education forms
• Literacy/language appropriate
Diabetes Care 1983; 6:499
J Gen Intern Med 2003; 18:258
©2006. American College of Physicians. All Rights Reserved.
www.ndep.nih.gov/diabetes/pubs/feet_kit_Eng.pdf
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
HIGH RISK: CATEGORY 1-3 PATIENTS
Regular prophylactic podiatry care:
–
–
–
–
Provide nail and skin care
Assess footwear needs
RCT: 48% RRR for recurrent ulceration
Optimal visit frequency not evidence-based:
Category 1  q 3-6 mo
Category 2  q 2-3 mo
Category 3  q 1-2 mo
Diabetes Care 2003; 26:1691
J Fam Practice 2000; 49(Suppl):S30
©2006. American College of Physicians. All Rights Reserved.
HIGH RISK: CATEGORY 1-3 PATIENTS
Intensive patient education:
– 1 care clinician, podiatrist, educator contribute
– Reinforce frequently – low retention documented
– Patient to demonstrate self-care knowledge
• Questionnaires, tests are available (see Tool-Kit)
– Utility:
• ? Reduced foot ulcer/amputation rates?
Cochrane Database Syst Rev 2005 Jan 25;(1)CD001488
Foot Ankle Int 2005; 26:38
©2006. American College of Physicians. All Rights Reserved.
BASIC FOOT CARE CONCEPTS
• Daily foot inspection
– May require mirror, magnification, or caregiver
– Educate patient to recognize/report ASAP:
• Persistent erythema
• Enlarging callus
• Pre-ulcer (callus with hemorrhage)
©2006. American College of Physicians. All Rights Reserved.
BASIC FOOT CARE CONCEPTS
• Commitment to self-care:
– Wash/dry daily
• Avoid hot water; dry thoroughly between toes
– Lubricate daily (not between toes)
– Debride callus/corn to reduce plantar pressure 25%
• Avoid sharp instruments, corn plasters
– No self-cutting of nails if:
• Neuropathy, PAD, poor vision
©2006. American College of Physicians. All Rights Reserved.
BASIC FOOT CARE CONCEPTS
• Protective behaviors:
– Avoid temperature extremes
– No walking barefoot/stocking-footed
– Appropriate exercise if sensory neuropathy
• Bicycle/swim > walking/treadmill
– Inspect shoes for foreign objects
– Optimal footwear at all times
©2006. American College of Physicians. All Rights Reserved.
FOOT CARE EDUCATION TOOLS
• “Prevent diabetes problems: Keep your feet and skin healthy”
 Cartoons – minimal text – still simple
 www.niddk.nih.gov or [email protected]
• “Take Care of Your Feet For a Lifetime” – booklet
 Few cartoons – more advanced
 http://ndep.nih.gov/materials/pubs/feet/brochure/index.htm
• “Take Care of Your Feet For a Lifetime” – 1 page summary
 www.ndep.nih.gov/diabetes/pubs/FootTips.pdf
©2006. American College of Physicians. All Rights Reserved.
FOOT CARE EDUCATION TOOLS
“Diabetic Foot Care”
– American Orthopedic Foot and Ankle Society
– Multilingual translation
• Available in 20 languages
– Reference:
Trepman E, et al. Foot and Ankle International
2005; 26:64-107.
©2006. American College of Physicians. All Rights Reserved.
EDUCATIONAL DEFICIENCIES:
HIGH RISK PATIENTS
• 558 high risk patients:
Deficiency
% Deficient
Not inspect feet regularly
Walk barefoot/stockings
Seldom/never test water temp.
Trim callus with sharp object
Not know to call ASAP for foot ulcer
Not know how to select footwear
From GE Reiber, 2003
©2006. American College of Physicians. All Rights Reserved.
50%
62%
40%
48%
58%
57%
BASIC FOOTWEAR EDUCATION
Avoid:
Pointed-toes
Slip-ons
Open-toes
High heels
Plastic
Black color
Too small
Favor:
Broad-round toes
Adjustable (laces, buckles,
Velcro)
Athletic shoes, walking shoes
Leather, canvas
White/light colors
½” between longest toe and
end of shoe
Diabetes Self-Management 2005; 22:33
©2006. American College of Physicians. All Rights Reserved.
THERAPEUTIC FOOTWEAR: GOALS
• Inappropriate footwear:
– Contributes to 21-76% of ulcers/amputations
• Optimal footwear should:
–
–
–
–
Protect feet from external injury
Reduce plantar pressure, shock and shear forces
Accommodate, stabilize, support deformities
Suitable for occupation, home, leisure
Diabetes Care 2004; 27:1832
Diab Metab Res Rev 2004; 20(Suppl1):S51
©2006. American College of Physicians. All Rights Reserved.
THERAPEUTIC FOOTWEAR: COMPONENTS
• Padded socks (eg. CoolMax, Duraspun, others)
– Cushion metatarsal heads, heels, and decrease plantar
pressure
– White, seamless, absorbent acrylic fibers
• Shoe inserts/insoles (closed-cell foam, viscoelastic)
– Off-the-shelf
– Custom-molded
• Therapeutic shoes
– Extra-depth  extra-width
– Rigid rocker outsoles
– Custom-molded
©2006. American College of Physicians. All Rights Reserved.
FOOTWEAR RECOMMENDATIONS BY RISK LEVEL
Low Risk (0)
Proper style/fit, cushioned stock shoes
 Sensation (1)
Deep toe box shoes, cushioned insoles
Callosities, ulcer Hx Extra-depth stock shoes, custom-molded insole
Severe deformities
Custom-molded extra-depth shoes and insoles,
rigid rocker outsoles
Modified from The Foot in Diabetes, 2000, p.136
©2006. American College of Physicians. All Rights Reserved.
THERAPEUTIC FOOTWEAR: EFFICACY
• Decreases plantar pressure 50-70%
• Uncertain reduction in ulcer rate:
– 1 prevention: no data
– 2 prevention: controversial reduction of ulcer recurrence
• Analytic/descriptive studies
• 2 RCTs
decreases ulcers 50-75%
no benefit
• Benefits vary with footwear use, risk level?
– Severe foot deformity, prior toe/ray amputation?
Diabetes Care 2004; 27:1774
©2006. American College of Physicians. All Rights Reserved.
MEDICARE COVERAGE OF THERAPEUTIC FOOTWEAR
• Certify diabetic patient with foot-at-risk
– 1° care physician
• Prescribe therapeutic footwear
– D.P.M., D.O., M.D.
• Prepare/fit therapeutic footwear
– Pedorthist, orthotist, prosthetist, D.P.M.
• www.cpeds.org
Foot Ankle Int 2005; 26:42
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
MEDICARE COVERAGE OF THERAPEUTIC FOOTWEAR
• Medicare pays 80% of payment amount allowed:
Extra Depth shoes
Custom-made shoes
Diabetic Pre-fab Insoles
Diabetic Custom Insoles
Total Amount Amount Covered by
Allowed
Medicare
$132.00
$105.60
$396.00
$316.00
$67.00
$53.60
$67.00
$53.60
1 pair extra-depth shoes  3 pair insoles/y, or
1 pair extra-depth shoes with modification
 2 pair insoles/y, or
1 pair custom-molded shoes  2 pair insoles/y
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
©2006. American College of Physicians. All Rights Reserved.
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Diabetic Foot Ulcer: Screening and Prevention