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 ulcersLancet 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.
Sensory Joint Motor Autonomic PAD
Neuropathy Mobility Neuropathy Neuropathy
Protective Muscle atrophy and Sweating Ischemia
sensation 2° foot deformities 2° dry skin
Foot pressure Foot pressure Fissure HealingMinor trauma esp. over recognition bony prominences
Callus Pre-ulcer ULCER Infection AMPUTATION
Minor Trauma: Interdigital Maceration
Mechanical (Moisture, Fungus)
Chemical
Thermal
PATHOGENESIS OF DIABETIC FOOT ULCER AND AMPUTATION
©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 % Causal Pathways
NEUROPATHY Neuropathy: 78%
Minor trauma: 79%
DEFORMITY Deformity: 63%
Behavioral issues ?
MINOR TRAUMA
- Mechanical (shoes) POOR SELF-
- Thermal FOOT CARE
- Chemical
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 pathologyArch Intern Med 1998; 158:157
©2006. American College of Physicians. All Rights Reserved.
RISK STRATIFY FOR FOOT ULCERATION
Foot Ulcer, % Office PatientsRisk Level %/yr (diabetes clinics)3: prior amputation 28.1% 7% prior ulcer 18.6%
2: insensate 6.3% 10% and
foot deformity or
absent pedal pulses
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 EXAMS2000 Behavioral Risk Factor Surveillance System, CDC
Total
Private
Insurance
Medicaid-
Medicare VA Uninsured
% with foot
exam in
past year
63 64 65 84* 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
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©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.
(After Pompogelli and Campbell, 2002)
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
HX TO DETECT PAD IN DIABETES
©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
ABINormal 0.91-1.30Mild obstruction 0.71-0.90
*Moderate obstruction 0.41-0.70 *Severe obstruction 0.40
**Poorly compressible >1.30 2° to medial Ca++
*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.
From Levin and Pfeifer, The Uncomplicated Guide to Diabetes Complications, 2002
• Hammer Toes
• Claw Toes
©2006. American College of Physicians. All Rights Reserved.
From Levin and Pfeifer, The Uncomplicated Guide to Diabetes Complications, 2002
Hallux Valgus
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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 50%
Walk barefoot/stockings 62%
Seldom/never test water temp. 40%
Trim callus with sharp object 48%
Not know to call ASAP for foot ulcer 58%
Not know how to select footwear 57%
From GE Reiber, 2003©2006. American College of Physicians. All Rights Reserved.
BASIC FOOTWEAR EDUCATION
Avoid:
Pointed-toes
Slip-ons
Open-toes
High heels
Plastic
Black color
Too small
Favor:Broad-round toesAdjustable (laces, buckles,
Velcro)Athletic shoes, walking shoesLeather, canvasWhite/light colors½” 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 decreases ulcers 50-75%
• 2 RCTs 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:
Total Amount Amount Covered by Allowed Medicare
Extra Depth shoes $132.00 $105.60Custom-made shoes $396.00 $316.00Diabetic Pre-fab Insoles $67.00 $53.60Diabetic Custom Insoles $67.00 $53.60
1 pair extra-depth shoes 3 pair insoles/y, or1 pair extra-depth shoes with modification 2 pair insoles/y, or1 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.