2. Introduction
• Principles of etiology, treatment and
prevention established by pioneer work of
Paul Brand
• One of the commonest complications
• Major limb amputation – end point of foot
lesions in diabetes
• Classical triad – Neuropathy, Ischemia,
Infection
• Advanced diabetic foot is like
prothrombotic stage
3. Epidemiology
1. Foot Ulcers
• 15% of all diabetic individuals during their
life time
• 85% of amputations are preceded by
diabetic foot ulcers
• Most important risk factors are –
Peripheral sensory neuropathy followed by
PVD
• The proportions of neuropathic 54%,
neuroischemic 34%, purely ischemic 10%
in diabetics
4. Epidemiology
• 2. PVD
• Asians ( 3-6% ) Western ( 25-45%)
• Prevalence increases with advancing
age , increased duration of diabetes
• 3. Lower Extremity Amputation
• Rates increase with advanced age. Higher
in males than females
• Approx 50% of amputees undergo second
or contralateral amputation (leg) within 1-3
yrs
5. Epidemiology
• In western pts – mortality, contra limb
amputation, AKA is higher mainly because
of older age, generalized atherosclerosis
and multi-system involvement
• In west most common indication for major
limb amputation is neuro-ischemic foot
while in India it is neuropathic foot with
secondary infection mainly because of
incorrect or delayed treatment
6. Classification
I Into 3 types
Neuropathic Foot – Neuropathy dominates.
Fissures, bullae, neuropathic joints and
edema, digital necrosis.
Neuroischemic Foot – Occlusive vascular
disease main factor while neuropathy is
present. Rest pain, foot margin
ulceration, digital necrosis and
gangrene.
Non neuroischemic foot – No significant
neuropathy or ischemia. Secondary to
trauma. Infected because of
uncontrolled, often undetected diabetes
7. Classification
• II. Wagner’s Classification ( Grading )
Specific for neuropathic foot & secondary
infection
• Grade 0 - No ulceration in a high risk foot
• Grade 1 - Superficial ulceration
• Grade 2 - Deep ulceration up to tendon,
ligament, deep fascia, bone or joint
• Grade 3 - Osteomyelitis or deep abscess
• Grade 4 - Localized gangrene
• Grade 5 - Extensive gangrene requiring
major amputation
8. Risk Factors
1. Smoking
2. Hypertension
3. Hyperlipidaemia
4. Insulin resistance with compensatory
hyperinsulinaemia
5. Severity and duration of diabetes
6. Age
7. Genetic predisposition
9. Pathogenesis
1. Neuropathy
-Chronic sensitomotor peripheral
neuropathy is most common long term
complication
-Components of peripheral neuropathy are
sensory neuropathy, motor neuropathy,
autonomic neuropathy.
-Loss of sensation -> trauma -> ulceration
-Loss of proprioception -> foot deformities ->
ulceration
-Sympathetic dysfunction -> infection
10. Pathogenesis - Neuropathy
-The atrophy of intrinsic muscle of foot
predominantly plantar flexors of toes alters
flexor/extensor balance at MPJ-claw toes
and prominent metatarsal heads (due to
pushing forward of fibro-fatty metatarsal
cushions)
-Footshape alter- increases plantar pressure
-Majority of wounds-occur from continuous
pressure
-Callus acts as foreign body & increases
plantar pressure exacerbating the problem
12. Pathogenesis - Neuropathy
• Walking briskly-progressive hyperemia
over points of maximum stress
• Thermography outlines temperature
contrast of progressive inflammation from
such a process
• Insensitive feet-hyperemia at old scars site
• In shoe foot prints-points of persistent and
maximum stress on feet
13. Pathogenesis - Neuropathy
• Classical peripheral neuropathy – bilateral
and symmetrical
• Sensory component predominates –
subjective pain & paraesthesia, objective
examination blunting sensation of pain &
temperature “The painful painless leg”
• Sensory disturbance-distal portion lower
extremities eventually progressing to stock
and glove distribution
• Involvement of sensory & motor fibers
impairs light touch & proprioception
14. Foot ulcer vs. Neuropathy
C fiber dysfunction Large fiber
dysfunction
loss of pain & warm loss of vibration &
thermal perception position sensation
wasted interossei equinus
hammer toes warm feet
dry scaly feet osteopenia
decreased blood flow increased blood flow
16. Foot tests
• Pin prick test – use a disposable
instrument e.g. a disposable pin
• Light touch – use a consistent method,
ideally a cotton wisp
• Vibration test – use 128 Hz tuning fork,
initially on the big toe
• Pressure perception - 10g monofilament
absence of sensation in the foot
• Ankle reflex – compare it with knee reflex
17. Pathogenesis
2. Biochemical aspect
- The non - enzymatic glycosylation of
collagen leads to thickening and cross
linkage of collagen bundles, stiffness of
ligaments - restrictions in the range of
motions of the joints of foot particularly in
sub talar joint and ankle leading to
increased plantar pressure and alters
mechanism of walking
• Limited joint mobility also occurs in hands
18. Pathogenesis
3. Biomechanics
- Commonest sites of ulceration-in forefoot
- Ulcers occur at sites of high pressure on
either plantar or dorsal surface
- Ulcers caused by undue bony
prominences, ill fitting footwear and toe
deformities
- Foot deformities result from atrophy of
intrinsic muscles of foot
19. Pathogenesis - Biomechanics
• Altered foot architecture, loss of flexibility
and free joint movements – relatively rigid
and unstable foot with altered weight
bearing pressure areas
• Bony prominences push forward the fibro-
fatty shock absorbing pads exposing
condyles of metatarsal heads
• Combination of risk factors & neuropathy
increase plantar pressure on forefoot &
hallux, significantly increasing risk of foot
ulceration
20. Pathogenesis - Biomechanics
• Semi quantitative estimation of plantar
pressure – ink pad on which patient’s foot
leaves an impression in different shades.
Quite specific, not very sensitive
• Bare foot measurements – pts walk onto
platform, information from single foot
contact collected
• In-shoe measurements – matrix of
transducers manufactured into thin pliable
insole placed in shoe in direct contact with
foot, information from multiple steps
21. Pathogenesis - Biomechanics
-Normal peak plantar pressures 50-300 KPa
-Pressures lowest on mid foot region,
highest on heel, heads of first 3
metatarsals and hallux
-In diabetes peak plantar pressure-
increased 2-3 folds
-Elevated plantar pressure major factor in
pathogenesis of plantar ulcer
-In-shoe measurements refine footwear
prescription by defining exact degree of
pressure relief at high risk areas
22. Pathogenesis
4. Haemorrheology
- Macro vessel haemorrheology constituted
by Hct, plasma viscosity, platelet activity
and RBC aggregation
- Micro vessel haemorrheology involves
RBC and WBC deformability
- All these components are altered in
diabetics, accentuating ischaemic process
due to structural changes in large and
small blood vessels
23. Pathogenesis
5. Infection
- Frequent and severe infections in
diabetics due to vascular insufficiency
- In presence of infection increased blood
supply cannot be met. Skin breaks down
and tissue necrosis – nidus for organisms
- Bacteroids commonest
- Soft tissue gas formation by coliform
group (aerobic/anaerobic G –ve rods),
streptococci, staphylococci
24. Pathogenesis - Infection
-Non healing ulcer over bony prominence –
suspect osteomyelitis. It should be
differentiated from diabetic osteopathy
occurring as a result of denervation
-Radiological hallmark of diabetic
osteopathy “ peppermint stick sign “ –
pointed distal metatarsal
-Diabetic osteopathy distribution multifocal &
bilateral. Associated with normal WBC
count & ESR
25. Pathogenesis
6. Peripheral vascular disease
-Bilateral pathology, multi-segmental,
predilection for vessels below popliteal
artery
-collateral vessels are involved in diabetes
-Gangrene occur in patchy areas of foot &
toes
-Present with intermittent claudication,
nocturnal pain and rest pain
26. Features of ischemic foot
• Thin atrophic feet, thickened nails, sparse
hair
• Painful lesions: dry gangrene confined to
toe or heel, or extensive or superinfected
• Cold feet that become pale on elevation &
cyanosed on depression
• Weak/absent peripheral pulses
• Slow venous filling
• Vascular investigation – ischemia
• Normally/slightly reduced reflexes or
sensation
27. Features of neuropathic foot
• Disproportion between lesions and
absence of pain
• Keratosis, cracks, ulcers & plantar ulcers
• Deformity of foot & toes, amyotrophy
• Loss of sense of touch, pain, vibration &
tendon reflexes
• Warm dry feet, venous congestion, edema
• Pulses present, no evidence of ischemia
on investigation
28. Pathogenesis - PVD
• Ankle-toe pressures, ankle-brachial
systolic pressure ratio (ischaemic index),
pattern of flow – indices for assessment
• Normal ankles-brachial systolic BP is >1.0
and values <0.6 - significant arterial stenosis
• Doppler USG pulse wave in peripheral
vessels
• Ankle pressure <70 mmHg– poor healing,
>100 mmHg good prognosis
• Toe pressure <20 mmHg- increased
failure of distal amputation, >40 mmHg
good prognosis
29. Foot ulcer risk factors
• Risk factor
Neuropathy
• Screening method
Clinical examination, pressure & vibration
perception threshold
• Abnormal result/risk of foot ulceration
Absent ankle reflexes or sensory loss,
insensitivity to 10g monofilament on
plantar surface
Vibration >25 V at the greater toe
30. Foot ulcers risk factors
• Risk factor
PVD , previous foot lesion
• Screening method
Clinical examination, doppler pressures,
history
• Abnormal result/risk of foot ulceration
Less than 2/4 palpable foot/ankle pulses
Systolic ankle pressure<90% of brachial
pressure
History of ulcer or amputation
31. Pathogenesis - PVD
• Sophisticated techniques like skin blood
flow calculated from xenon-133 clearance,
a micro-invasive procedure &
transcutaneous oxymetry
• Cutaneous blood flow of >2.6ml/100g/min
associated with good healing
• However above indices cannot predict
healing accurately because state of local
wound dominates the outcome
• Neuropathy is starter, Vasculopathy is
chaser, Infection is perpetuator
32. Clinical evaluation
1. History
The inciting event may be cutting a toenail,
soaking the foot in a warm bath, or
applying a heating pad.
The duration of the ulcer- long-standing,
nonhealing ulcer is strongly suggestive of
ischemia heal with some further treatment,
whether it be offloading of weight-bearing
areas, treatment of infection, or correction
of arterial insufficiency.
33. Clinical evaluation -history
History of intermittent healing & relapse -
possibility of underlying untreated infection
(recurrent osteomyelitis) or uncorrected
architectural abnormality (bony/varus
deformity).
Type and duration of treatments for the
current problem - patient with an ischemic
ulceration may have completed several
different antibiotics courses without
success. It is also helpful to know which
treatments were not previously offered to
the patient and to look critically at why
they were not offered.
34. Clinical evaluation -history
Inquiries - previous foot and limb problems,
ulcers on the same foot that healed
spontaneously, duration of healing, foot
surgery on that side. History of previous
leg revascularization (including
percutaneous therapies) clue to underlying
arterial insufficiency. Predilection for mirror
image-atherosclerotic occlusive disease,
the contralateral leg must be considered
as well.
Other cardiovascular risk factors, such as
cigarette smoking and hyperlipidemia,
must also be taken into account
35. Clinical evaluation -history
The patient should be asked about
worsening hyperglycemia, recent blood
glucose control, and higher insulin
requirements. As a consequence of the
microvascular and neuropathic
abnormalities, classic symptoms of
infection (e.g., chills and pain) are often
absent, and hyperglycemia is often the
sole presenting symptom of undrained
infection. Faced with ongoing infection and
hyperglycemia, the surgeon should
strongly suspect impending ketoacidosis
or NKHOC, with symptoms of weakness,
confusion, and altered mental status
36. Clinical evaluation -history
Patients with a diabetic foot often need
some type of operative intervention -
history should include comprehensive
assessment of overall health status to
stratify perioperative risk e.g. previous
cardiac events (MI/revascularization) and
current cardiac status help determine
whether perioperative cardiac monitoring
or preoperative cardiac testing is indicated
Similarly, in patient with infection &
ischemia, h/o worsening renal function or
need for hemodialysis determine choice &
dosage of antibiotics & plan for contrast
37. Clinical evaluation
2. Physical examination
Fever and tachycardia- suggestive of deep
or undrained infection, with hypotension
being a late manifestation of ongoing
sepsis.
However, that these signs may be absent in
diabetic patients with impending or
progressive infection.
38. Clinical evaluation-Physical
examination
Evaluation of the diabetic foot ulcer should
include suspicion of infection and a
thorough search for it.
In a patient with cellulitis, the entire foot,
including the web spaces and the nail
beds, should be examined for any
potential portals of entry, such as a
puncture wound or an interdigital ulcer.
Encrusted and heavily calloused areas over
the ulceration should be unroofed and the
wound thoroughly inspected to determine
the extent of involvement.
39. Clinical evaluation-Physical
examination
A benign-appearing dry gangrenous eschar
often hides an undrained infectious
collection
Cultures should be taken from the base of
the ulcer; superficial swabs may yield only
colonizing organisms
Purulent discharge, crepitus, tenderness,
erythema, and sinus formation indicate
infection. With more advanced and deep
infection, edema may be present as a
result of elevated pressures within one or
more of the plantar compartments.If left
untreated,it may spread proximally along
tendon sheaths to involve ankle or calf.
40. Clinical evaluation-Physical
examination
Close inspection of the ulcer and the use of
a sterile probe confirms the presence of
osteomyelitis. If bone is detected with
gentle probing, osteomyelitis is presumed
present.
Neuropathy should be assessed by 10g
monofilament; inability to feel the
monofilament correlates with an increased
risk of foot ulceration. Advanced
sensorimotor neuropathy leads to claw
foot or Charcot degeneration -> abnormal
pressure points on the plantar
41. Clinical evaluation-Physical
examination
Physical examination must include a
systematic approach to the assessment of
arterial insufficiency.
Simple inspection of the leg, foot & ulcer,
provides suggestive clues e.g. distal
ulceration on the tip of a digit, ulceration
unassociated with an exostosis or a
weight-bearing area, and gangrene are
consistent with underlying ischemia
The presence of multiple ulcerations or
gangrenous areas on foot, absence of
granulation tissue, lack of bleeding with
42. Clinical evaluation-Physical
examination
Other signs- pallor with elevation, fissures
(particularly at the heel), absence of hair
growth, poor skin condition and
hyperkeratosis should be noted
The pulse examination, including of foot
pulses, is the most important component
of the physical examination. Absence of a
palpable pulse indicates ischemia.
43. Clinical evaluation-Physical
examination
The femoral pulse - palpated midway
between the ASIS and the pubic tubercle,
just below the inguinal ligament.
The popliteal pulse - palpated with both
hands and with the knee flexed no more
than 15°.
The dorsalis pedis is located between the
first and second metatarsal bones, just
lateral to the extensor hallucis longus
tendon, and its pulse is palpated with the
pads of the fingers as the hand is partially
wrapped around the foot . If the pulse
cannot be palpated, the fingers may be
moved a few millimeters in each direction
44. Clinical evaluation-Physical
examination
posterior tibial artery is located in the hollow
curve just behind the medial malleolus,
approximately halfway between the
malleolus and the Achilles tendon. The
examiner's hand should be contralateral to
the examined foot (i.e the right hand
should be used to palpate the left foot, and
vice versa), so that the curvature of the
hand naturally follows the contours of the
ankle
45. Assessment of clinical findings
Once the clinical evaluation is complete, the
next step is to assess the findings from
the history and the physical examination
This assessment is made at the bedside,
focusing on three main concerns:
1. The presence and severity of infection –
first priority in management of diabetic
foot
2. The salvageability of the limb
3. The presence of ischemia.
46. Infection
Infection in diabetic foot range from minimal
superficial infection to fulminant sepsis
with extensive necrosis tissue destruction
The microbiology varies according to the
depth and severity of the infection and the
nature of the patient's environment -
hospitalized or outpatient.
Mild localized and superficial ulcerations,
particularly in outpatients, are usually
caused by aerobic gram-positive cocci -
Staph aureus and streptococci.
47. Infection
Deeper ulcers and generalized limb-
threatening infections are usually
polymicrobial. Gram-positive cocci, gram-
negative bacilli - E coli, Klebsiella,
Enterobacter aerogenes, Proteus
mirabilis, and Pseudomonas aeruginosa,
and anaerobes - Bacteroides fragilis and
peptostreptococci.
Enterococci may also be isolated from the
wound, notably in hospitalized patients; in
the absence of other cultured virulent
organisms, they should probably be
considered pathogenic.
48. Infection
Currently, S. aureus (MRSA), are playing a
growing role in the development of skin and soft
tissue infections. Traditionally arising in patients
who had previously been hospitalized and those
who had previously received antibiotic therapy
Awareness of increasing prevalence of resistant
organisms is critical for management
In a compliant patient with a small ulcer and no
evidence of deep space involvement or systemic
infection, treatment may be delivered on an
outpatient basis.
49. Infection
A dual-antibiotic regimen (pending culture
results) typically consisting of a
cephalosporin or a betalactam antibiotic
(for activity against staphylococci and
streptococci) and vancomycin (for activity
against MRSA).
A dual regimen consisting of fluoroquinolone
and linezolid is an alternative that also
provides adequate coverage.
In addition, the patient is instructed to
offload weight from the involved extremity
and is taught appropriate methods for
changing wound dressings. Frequent
50. Infection
A more common presentation - patient with
ulceration/gangrene with deep infection
affecting tendon/bone and systemic
involvement - immediate hospitalization
indicated, bed rest, elevation of the foot,
correction of any systemic abnormalities,
and broad-spectrum I.V. antibiotic therapy
(which may be focused more tightly once
culture results are complete).
Because the clinical findings of impending
sepsis may be subtle, these patients
should undergo a complete laboratory
workup to detect and correct electrolyte
51. Infection
The choice of antibiotics and duration of
therapy are dependent on the extent of the
infection.
For patients with deep/chronic recurrent
ulcers, typically polymicrobial, or limb or
life-threatening infections, appropriate
empirical antibiotic options include
(1) vancomycin + betalactam antibiotic with
a betalactamase inhibitor (e.g.,
piperacillin-tazobactam)
(2) Vancomycin + metronidazole plus a
52. Infection
In the absence of osteomyelitis, antibiotics
should be continued until the wound
appears clean and all surrounding cellulitis
has resolved typically, 10 to 14 days
If osteomyelitis is present, treatment should
include both surgical debridement and a
prolonged (4-6 week) course of antibiotic
therapy (though the course may be
abbreviated if the entire infected bone has
been removed, as with digital or
transmetatarsal amputation)
53. Infection
Heel lesions often present with some degree
of calcaneal destruction & determination of
osteomyelitis may be made by clinical
examination either alone or in conjunction
with other radiographic tests MRI.
In the presence of an abscess/deep space
infection, immediate I &D of all infected
tissue planes is mandatory. Incisions
should be chosen with an eye to the
normal anatomy of the foot (including the
various compartments) and the need for
subsequent secondary (foot salvage)
procedures. Drainage should be complete,
with incisions placed for dependent
drainage, and all necrotic tissue debrided.
54. Infection
Drainage incisions on the dorsum of the foot
should be avoided.
Abscesses in the medial, central, or lateral
compartment should be drained via
longitudinal incisions made in the direction
of the neurovascular bundle and extending
the entire length of the abscess.
The medial and central compartments are
drained through a medial incision, and the
lateral compartment is drained through a
lateral incision; both of these incisions are
made just above the plantar surface of the
forefoot
55. Infection
Web space infections may be drained
similarly through the plantar aspect of the
foot.
A patient with an ongoing undrained
infection may present with an
unsalvageable foot and fulminant sepsis.
Such patients should undergo prompt
open (guillotine) below-the-knee
amputation
This type of amputation is usually performed
at the ankle level, with the aim of removing
the septic source while allowing for
revision and closure at a later date.
56. Infection
Administration of I.V. antibiotics, correction
of electrolyte abnormalities, continuous
cardiac monitoring are essential
throughout treatment
Once debrided,wound inspection and
management are essential. Ongoing
necrosis should raise the possibility of
undrained infection or untreated ischemia,
in which case further debridement and
treatment may be necessary.
Avoidance of weight-bearing should be
continued.
57. Medical stabilization
Hyperglycemia is almost always seen when
infection is present; it should be gradually
corrected. Serum concentrations of
electrolytes, magnesium, and creatinine
Dehydration is common in hyperglycemic
patients and should be corrected
A urinary catheter is mandatory to help
guide the response to fluid therapy; in
unstable patients
Continuous cardiac monitoring is essential
in patients with the hyperglycemic
hyperosmolar syndrome or ketoacidosis.
58. Salvageability of limb
Determined largely on the patient's
functional status and the degree of foot
destruction. For example, primary limb
amputation may be considered in a
nonambulatory, bedridden patient or in a
patient with severe Charcot degeneration,
for whom no further reconstructive foot
surgery is possible
Assessment of limb salvageability carried
out simultaneously with treatment of
infection because appropriate drainage
and antibiotics can dramatically change
the appearance and viability of the foot.
If limb salvage not possible, BKA or AKA
done
59. Ischaemia
Patients who might benefit from testing for
ischaemia include
• Those with absent foot pulses
• Who have a superficial ulcer with evidence
of healing or a previous history of a healed
foot ulcer
• Those without any foot lesions who are
scheduled to undergo elective foot
surgery.
Segmental Doppler waveforms and pulsed
volume recordings are unaffected by
medial calcification
60. Ischaemia
• Regional transcutaneous oximetry
measurements are also unaffected by
medial calcinosis, and this modality
appears to be reliable for predicting ulcer
healing and amputation levels
• However, measurements are actually
higher in patients with diabetics possibly
because of the effects of arteriovenous
shunting
61. Ischaemia
In evident ischemia, arteriography of the
entire lower extremity should be
performed. For a complete assessment,
the arteriogram should include the foot
vessels in both lateral and anterior views
62. Management
1. Revascularization
• approaches include endovascular
techniques (angioplasty and stenting)
• Bypass grafting (with autogenous or
prosthetic grafts)
• Combination of the two.
• In patients with isolated iliac artery
stenoses, angioplasty may be effective
by itself, but in patients with multilevel
disease, it may have to be combined
with an infrainguinal bypass
63. Revascularization
Arterial bypass grafting is required for
restoration of the foot pulse
Proximal bypass to either the popliteal,
tibial, peroneal arteries may restore foot
pulses
Restoration of pulsatile flow to the foot may
be accomplished with autogenous vein
bypass grafts to the paramalleolar or
inframalleolar arteries (e.g., the dorsalis
pedis)
The vein graft can be prepared as an in situ
graft, a reversed graft, or a nonreversed
64. Management
2. Wound care
Wounds should be kept moist - wet
dressings
Chemical enzymatic debriding agents
Growth factors
Hyperbaric oxygen therapy
Hyperglycemia and malnutrition correction
65. Management
3. Secondary foot procedures
Goals
(1) to remove infected bone (if present)
(2) to restore functional stability,
(3) to reduce risk of subsequent ulceration
In the forefoot- digital, ray, or
transmetatarsal amputation performed,
depending on the location of the ulcer.
66. Secondary foot procedures
Bony deformities corrected with hallux
arthroplasty, metatarsal head resection,
metatarsal osteotomy, or sesamoidectomy
Ulceration on a previous transmetatarsal
amputation may be the result of an
equinovarus deformity (from disrupted
tendons and a decrease in calcaneal
inclination). Treated with revision of the
transmetatarsal amputation (perhaps in
conjunction with ulcer excision) and
biomechanical correction (e.g., Achilles
tendon lengthening or, in more severe
cases, posterior tibial tendon release).
67. Secondary foot procedures
In heel lesions dry eschars with no evidence
of deep infection/abscess treated with
offloading alone in the fully revascularized
foot.
In patients with chronic ulceration or
osteomyelitis, partial calcanectomy may
be considered. adjunctive studies such as
MRI
Given the relatively fixed nature of the heel,
either secondary healing or some type of
flap coverage is usually indicated
68. 3. Preventive foot care
patient education, focusing on general
hygiene, daily inspection of the feet.
To avoid walking barefoot, employing heat
pads, wearing thong sandals
69. Foot wear prescription
• Outsole – should be tough to prevent
penetrating injuries, serrated, heel should
be 5 cm
• Shoe size – length of shoe should allow
1.25 cm b/w end of shoe & longest toe &
widest at 1st
MTP joint
• Countor
• Shoes with laces – adjustability needed for
edema and deformities
70. Foot wear prescription
• Shoe depth – extra depth to allow dorsal
deformities & removable insoles
• Toe box – rounded & high toe box to
accommodate dorsal deformity
• Uppers – soft inner lining to prevent
bunions
• Insoles - cushioning & allow distribution of
plantar pressures