Presentation of Diabetic foot assessment and orthopaedic treatment

1. DIABETIC FOOT
CHAPTER 85 CAMPBELLS

2. HISTORY AND PHYSICAL EXAMINATION
The physician should inquire about :
 any episodes of ulceration
 prior amputations
 known neuropathic arthropathy
 impaired vision
 renal history
 presence of paresthesias or numbness
 any symptoms of claudication
 patients may deny any history of trauma or pain before the development of a foot ulcer

3.  A difference in skin temperature of the foot may indicate the presence of a
vascular disease

4.  Diminished or absent pulses require further testing with a Doppler examination

5.  The ankle-brachial index (ABI) is a useful noninvasive screening tool that is
predictive of wound healing. A normal ABI is 0.9 to 1.2 while values over 1.3
suggest noncompressible vessels due to calcification.
 An ABI of less than 0.5 suggests that an ulcer is unlikely to heal without vascular
intervention

6.  A difference in ABI of more than 0.15 between extremities is a significant finding
and should be further investigated.

7.  Absolute toe pressures should be higher than 70 mmHg, and a normal
toe/brachial index of more than 0.7 is normal.
 Toe pressures of more than 40 mmHg are associated with wound healing.

8.  A neurologic examination evaluates for the presence or absence of peripheral
neuropathy.

9. Semmes-Weinstein monofilament
 The inability to feel the 10 g of pressure from this monofilament is one of the
most predictive risk factors for development of foot morbidity.
 Typical screening involves 10 g monofilament testing of 10 sites on the foot

11.  equivalent results can be obtained more quickly using a 4.5 g monofilament
beneath both first metatarsal heads.
 Decreased perception of the vibration of a 128 Hz tuning fork at the tip of the
great toe also is used in clinical practice.

12. ULCER CLASSIFICATION
 Ince et al. found that of 410 diabetic foot ulcers, 96% of those less than 1-2 cm in
dimension eventually healed without any form of amputation, while only 72% of
ulcers larger than 2-3 cm did so

20. LABORATORY EVALUATION
 Patients with hemoglobin A1c levels higher than 7% or preoperative glucose levels
of more than 200 mg/dL before ankle or hindfoot arthrodesis have a higher rate of
complications, including nonunion, infection, and wound healing problems.

21. If infection is suspected clinically:
 complete blood count(CBC)
 erythrocyte sedimentation rate (ESR)
 C-reactive protein (CRP)

23. TREATMENT
The primary goals of treatment of diabetic foot ulcers are :
 healing of the ulcer
 prevention of secondary infection
 recurrence
 avoidance of amputation

24. The most standard treatments are debridement and off-loading of the
affected area

25. Because of the complexities of treating diabetic feet, including :
impaired blood supply
osteoporotic bone
neuropathy
a multidisciplinary approach is most beneficial

26. Expertise often is needed from subspecialists in orthopaedics, vascular
Surgery , infectious disease , endocrinology, and wound nursing.

27.  Vascular consultation should be considered when rest pain , claudication , or
ischemic ulcers are present.

28.  Endocrinology may assist if blood glucose levels cannot be controlled by the
primary care practitioner or if the patient shows unusual response to standard
glycemic control measures.

29.  Infectious disease consultation may be helpful when a patient fails to respond to
empiric antibiotic therapy.

30.  Systemic factors, including glucose control , smoking, and diet, should be
controlled to optimize the wound-healing environment

31. Using the Wagner classification of foot ulcers:
 grade 0 ulcers should be treated with serial examinations, patient education,
accommodative footwear.
 Grade I ulcers can be treated with debridement in the clinic and off-loading
total contact cast, walking brace, or other custom footwear.

32. Grade II ulcers require
 surgical debridement
 culture-specific antibiotics
 off-loading with total anesthetic.

33.  Grade III ulcers require
surgical debridement or partial amputation with off-loading and culture specific
antibiotics.

34.  Grades IV and V ulcers require local or larger amputation based on the extent of
infection.

35.  In the ischemic classification of Brodsky et al :
 type B ischemia should be considered for noninvasive vascular testing and
reconstruction with bypass or angioplasty.

36.  Type C involvement may require reconstructive vascular surgery with partial
amputation

37.  while type D requires thorough vascular evaluation and likely major extremity
amputation.

38.  Negative pressure wound therapy(NPWT) devices are another option to assist in
ulcer healing.
 The exact mechanism of action of NPWT is unknown;however, studies have shown
that it may increase local blood flow, decrease edema, and increase the
concentration of growth factors in the local wound fluid

39.  Cultures of the ulcer generally are not recommended because the sensitivity in
isolating the causative organism is low

40.  Most ulcers are colonized with bacteria that has not invaded the deep tissue and
do not require antibiotics.
 When wound cultures are obtained , this should be done after thorough
debridement of the wound

41.  Harsh chemicals such as hydrogen peroxide and betadine should not be
applied because these can damage the viable tissue in the ulcer and further delay
healing.

42.  Routine nail care may be provided by the physician or nurse if the patient is
unable to do so.
 A straight nail clipper should be used to transversely cut the nail to avoid any skin
overgrowth at the medial and lateral borders, which may increase the chance of
developing an ingrown nail.

43.  Hyperbaric oxygen (HBO) has been used as a treatment for diabetic foot ulcers,
and randomized trials have shown 54% healing using HBO compared with 25%
for standard methods.

44. PATIENT EDUCATION
 Patient education for diabetic patients has been shown to be cost-effective,
improve patient quality of life, and reduce the risk of lower extremity amputation
by 50% to 85%.

45.  Patients should be reminded to wear shoes at all times.
 Feet should be inspected daily, and any signs of erythema, ulceration, or nail
problems should be brought to the attention of the care provider.

46.  Feet should be bathed daily with mild soap and a soft brush for the areas around
the nails.

47.  When drying the feet, attention should be paid to the web spaces because these
areas often trap moisture.
 If the web spaces remain overly moist, lamb’s wool may be placed in between the
toes to avoid maceration.

48. TOTAL CONTACT CASTING
 Reducing pressure on plantar ulcers is crucial to aid healing.
 Forefoot pressures can be reduced with prefabricated shoes more easily than
midfoot or hindfoot ulcers.

49.  Total contact casting is more effective than prefabricated shoes for the midfoot
and hindfoot (Fig. 85-11).

52.  A total contact cast redistributes forces from the plantar surface of the foot to
the leg , which reduces the force on the foot even with weight- Bearing activity.

53.  Total contact casting also is beneficial in that it reduces edema in the extremity,
which is why the cast must be changed regularly to prevent loosening that can
lead to further ulceration.

54.  Total contact casting for plantar ulcers showed significantly better healing (89.5%)
than removable prefabricated walking boots (65%) or shoes (58%).

56.  This is similar to the 88% healing rate reported at 41 days with total contact
casting alone in a study comparing casting alone to casting with percutaneous
Achilles lengthening.

57.  Patients have been shown to decrease their activity over the course of a day in a
total contact cast, which reduces the stress on the foot.

58.  Total contact casting is not a benign treatment, however; it has been shown to
have a 6% to 17% occurrence of new ulcer formation and a 0.25% rate of
permanent sequelae

59. Contraindications of Total contact cast
 absolute:
 active or acute deep infection,gangrene(wagner grade 3-5)
 deep tissue infection
 osteomyelitis
 exposed tendone , joint and bone
 arterial insufficiency/gangrene

60.  Relative:
 severe obesity
 ulcer depth greater than ulcer width
 fragile skin
 fluctuating edema
 patient unwilling to have cast on limb
 patient unable to comply with follow up visit
 Doppler ABI less than ./4

61. SURGICAL MANAGEMENT
 Indications for surgical management are grossly contaminated wounds,
unbraceable deformity, gastrocnemius contracture, underlying bone prominence
that impedes wound healing, and failure of conservative management.

62. Prophylactic surgery may be considered in patients who are at risk for
wound breakdown because of joint instability or bony prominence.

63.  Flexor tenotomy as treatment for isolated toe ulcerations showed over 90%
healing rates in a mean of 40 days, with a 12% recurrence rate at 2-year follow up.

64.  Ulcerations at the medial interphalangeal joint of the hallux can be treated by
resection of the medial condyles of the proximal and distal phalanges.

65.  Plantar metatarsophalangeal joint ulcerations are common, difficult to heal, and
associated with a high risk of amputation.

66.  Achilles tendon lengthening and/or gastrocnemius recession should be
considered for patients with forefoot ulcers in whom conservative management
has failed and contractures have developed.

68.  Exostectomy may be required in patients with bony deformity and ulceration.
 A sufficient period of off-loading with total contact casting should be completed
before surgery.

69.  For patients in whom other surgical management fails , who have non
reconstructable vascular disease, or in whom infection is uncontrollable,
amputation is the last surgical option.

70.  The National Diabetes Advisory Board estimates that approximately 5% to 15% of
diabetic patients will require a lower-extremity amputation in their lifetime.

71.  The level of amputation depends on the location of infection and likelihood of
healing of the surgical wound.

72.  One-year mortality after transtibial amputation is 20%, with a 5-year mortality
of 65%.
 Preservation of a portion of the foot gives the patient an end-bearing limb that
facilitates ambulation without a prosthesis and improves Functional outcome.

73.  In the forefoot, ray resection or transmetatarsal amputation may be sufficient
in a patient with palpable pulses; however, the same wound in a patient with
vascular pathology may require transtibial amputation

74.  In the midfoot,a talonavicular-calcaneocuboid disarticulation (Chopart) or syme
amputation may allow ambulation without prosthesis.
 A viable heel pad is required for a Syme amputation

76. Lisfranc Amputation

77. Chopart amputation

78. Syme Amputation

81. Boyd Amputation

82.  The single most important factor predicting success of a partial foot amputation
is the hemoglobin A1C level at time of surgery, with some authors
recommending no elective or trauma surgery for a diabetic patient with an A1C
level of more than 8% unless necessary to save life or limb.

83. CHARCOT ARTHROPATHY
 Diabetes is the most common cause of Charcot arthropathy today, but other
etiologies include syphilis, heavy metal poisoning, alcoholic or congenital
neuropathy, leprosy, rheumatoid arthritis, and idiopathic causes

84.  The neurovascular, or French, theory was first proposed by Charcot and suggests
that neurologic damage precedes and is responsible for the destructive changes.
It proposes that damage to the nervous system causes autonomic dysfunction,
which increases local blood flow due to arteriovenous shunting and leads to bone
resorption

85.  The neurotraumatic, or German, theory supported by Virchow and Volkman
suggests that repetitive microtrauma causes the bony changes due to absent
protective mechanisms.

86. CLASSIFICATION
 Type 1 involving the tarsometatarsal and naviculocuneiform joints is most
common (60%). Midfoot involvement, specifically the tarsometatarsal joints
characterized by hindfoot valgus as a result of forefoot abduction with a
contracted gastrocsoleus complex

87.  Type 2 is the second most common type (25%) and primarily involves the
hindfoot, including the subtalar, talonavicular, and calcaneocuboid joints, and may
also progress to a rocker-bottom deformity

89.  Type 3A (10%) involves the ankle and often results in ulcerations over the
prominent malleoli. Ankle involvement generally requires operative intervention
because of marked instability.
 Type 3B (5%) presents as a pathologic fracture of the calcaneal tuberosity from
avulsion

92. TREATMENT
 Stage 1 disease is treated with a total contact cast, which offloads the involved
region and provides stability and alignment through the healing phases.

93.  stage 2 , patients can be transitioned into a prefabricated boot or a custom-
molded ankle-foot-orthosis.

94.  When consolidation is complete and swelling resolves completely (stage 3)
intensive treatment, up to 50% may require surgical intervention

95.  Vitamin D supplementation should be considered for all patients because research
has shown frequent hypovitaminosis D in diabetic patients and clarified its role in
the pathogenesis and treatment of Charcot arthropathy.

96.  The primary goals of surgical intervention are to prevent ulceration, infection,
and amputation by decreasing sites of underlying pressure and improving
alignment and stability of the foot.

97.  Exostectomy is most beneficial in Brodsky type 1 deformities in which
tarsometatarsal destruction leads to rockerbottom deformity and increased
midfoot plantar pressures

98.  Patients with instability and resultant pain or ulceration may be best treated with
arthrodesis

99.  Type 1 deformities generally require midfoot arthrodesis, while type 2
deformities require triple arthrodesis

100.  In patients with uncontrollable infection or failed operative treatment, amputation
preserving as much length as possible may be the best option

101.  An estimated 2% to 3% of patients with Charcot arthropathy have amputations