Diabetic foot

Diabetic Foot

1. Diabetic Foot Grand Round Dr. V Singh Chauhan Mmed Orthopedics Dr. V. Singh Chauhan

2. Forlee M. What is Diabetic Foot?, ajol:2010 Dr. V. Singh Chauhan

3. What is Diabetic Foot Group of Syndromes where neuropathy / ischemia & Infxn leads to tissue breakdown Morbidity Amputation Infra- malleolar infxn (with DM) Dr. V. Singh Chauhan

4. Why is Diabetic Foot worth the interest? Amputations Awori KO, Atinga J. Lower Limb Amputations at KNH. East Afr Med J. 2007 Mar; 84(3) Pvd 55.3% Tumors 24.3% Trauma 18.9% Diabetic Gangrene 17.5% Dr. V. Singh Chauhan

5. Why is Diabetic Foot worth the interest? Amputations Chalya , Mabulo , Dass . Major Limb Amputations – Tertiary hospital experience in north western Tanzania. Journal of orthopedics research & Sx . 2012;7:18 Diabetic Foot 41.9% Trauma 38.4% Vascular Disease 8.0% Dr. V. Singh Chauhan

6. Why is Diabetic Foot worth the interest? Mortality Dr. V. Singh Chauhan

7. Why is Diabetic Foot worth the interest? Morbidity Wound care Ambulation Quality of life Dr. V. Singh Chauhan

8. Pathophysio of Diabetic Foot Multi-factorial, Complex and still poorly understood Neuropathy Vasculopathy Immune dysfunction Infection Prolonged Hyperglycemia contributes to all the above factors through different mechanisms Dr. V. Singh Chauhan

9. Pathophysiology Dr. V. Singh Chauhan

10. Dr. V. Singh Chauhan

11. Peripheral Neuropathy Main Issue Nerve Death due to Metabolic Changes Vascular Histological Dr. V. Singh Chauhan

12. Metabolic Mechanisms of neuropathy Buildup of sorbitol + fructose with decrease in myo-inositol + Na + /K + ATPase Why? Increase tissue Glc m’lised by alternative pathway due to decrease in insulin = Decreased nerve fxn + disruption of membrane ass. Na+ pump = Demyelination /nerve injury = Death (Due to failure to maintain normal polarised state) Dr. V. Singh Chauhan

13. Metabolic mechanism of neuropathy Loss of small sensory fibers Decrease in pain + Temp Loss of Large sensory fibers Decrease in Light touch + Proprioception Dr. V. Singh Chauhan

14. Effects of Peripheral Neuropathy Affects Sensory Motor Autonomic Dr. V. Singh Chauhan

15. Sensory Decreased sensation Unable to detect trauma / discomfort = repeated insult to tissue + bone Wounds go unnoticed Areas of pressure progressively deteriorate Loss of protective sense in joints = excessive force applied to ligaments + cartilage Joint erosion / Dislocation / #s & Charcot joints Dr. V. Singh Chauhan

16. Motor Motor nerves to intrinsic muscle affected Imbalance between flexion / extension Foot deformity – abnormal pressure areas hence skin breakdown + ulcerations E.g. Claw toe deformity Common Peroneal nerve also affected Foot drop due to loss of tibialis anterior motor fxn Dr. V. Singh Chauhan

17. Hammer Toes Claw Toes Dr. V. Singh Chauhan

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19. Limited Joint Mobility Syndrome Can affect the hand/joints/foot Due to loss of foot sensation/ proprioception & intrinsic muscle fxn Leads to wide based gait for balance that progresses to claw toes / midfoot valgus & calcaneoequinovalgus + decreased subtalar /ankle mvt Hence flat/stiff/insensate foot prone to injury & ulcer formation Dr. V. Singh Chauhan

20. Autonomic Decreased fxn of sebaceous glands of foot – decreased sweat and oil secretion Dryness of skin = cracks and infxn Local blood flow regulation Abnormal dilatation of the Arteriovenous shunts (Mostly in the skin of soles & not dorsum) Shunts – dilate in cold weather to direct flow from skin to core part of body Abnormal dilatation = bypass of blood from the skin Decrease in integrity of skin = dryness + Breakdown Dr. V. Singh Chauhan

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22. Peripheral Vascular Disease 2 mechanisms Atherosclerosis Monkenberg’s Medial Sclerosis Calcification of media of artery = rigid vessels without narrowing of lumen Interferes with measurements of doppler pressures – false high readings Dr. V. Singh Chauhan

23. 20-40% of DM pts have PVD Level of glycemic control plays a part 26% increase in risk of PVD for every 1% increase in HbA1c Usual sympts (ischemic rest pain etc) may be absent due to peripheral neuropathy Dr. V. Singh Chauhan

24. Pattern of atherosclerosis in DM as compared to non DM pts Affects younger patients More Aggressive Progression is faster Affects distal vessels > prox Rapid progression overcomes rate of distal collateral revascularization Role of bypass?? Dr. V. Singh Chauhan

25. Infections and Diabetic Foot Immunology Poor response to infection seen because  Polymorphonuclear leukocyte migration  Phagocytosis  Intracellular killing  Chemotaxis Antibiotics may be subtherapeutic in ischemic tissues Decreased blood flow in swollen and infected tissues = large necrotic dead spaces Dr. V. Singh Chauhan

26. Infections and Diabetic foot Usually polymicrobial During acute infxn – Staph aureus commonest Chronic infxn Polymicrobial (>75% of pts) > G- ve isolates (51.2%), G+ve (32%) Spectrum moves from gram + ve to G- ve , anaerobics as the wagner classification progresses Khalifa B, Ahmed M. Study of Microbiology of diabetic foot infxns in a teaching hospital in Kuwait. 2012, Vol 5; issue 1 Dr. V. Singh Chauhan

27. Infections and Diabetic foot Gitau A, Nganga Z. Fungal infections among diabetic foot ulcer patients at Kenyatta National Hospital; 2011, AJOL Showed significant fungal aetiological agents > seen in callus formation (78%) Dr. V. Singh Chauhan

28. Infections and Diabetic Foot Osteomyelitis Bone infected in at least 20% of foot ulcers Majority – contiguous spread from adjacent soft tissue infxn (not conventional) Frequently missed or under diagnosed = Amputations Risk of amputation increases 4X Presence of OM requires longer duration of antibiotic therapy Dr. V. Singh Chauhan

29. Infections and Diabetic Foot Commonest site Forefoot (90%) Midfoot & Hind foot – 5% each Commonest bone affected Tripod of foot 1 st metatarsal 5 th metatarsal Calcaneus Dr. V. Singh Chauhan

30. Infections and Diabetic foot Clinical testing with Probe to bone test Controversial Some studies – sensitivity 98%, Specificity 79% Plain Radiography 30-50% bone destruction to show visible changes (2-3 wks to manifest) Bone biopsy is gold standard Dr. V. Singh Chauhan

31. ASSESSMENT Dr. V. Singh Chauhan

32. History Duration of D.M (>10yrs) Age (>60yrs) Glycemic control CVS, Renal, Eye evaluations Social habits Current medications Allergies Previous hospitalizations / surgeries Dr. V. Singh Chauhan

33. Foot Specific History Daily activity Foot wear Chemical exposure Callus formation Deformity Previous foot surgery Neuropathic / ischemic symptoms Dr. V. Singh Chauhan

34. Wound/Ulcer History Location Duration Inciting event / trauma Infection Wound care/ off loading methods Compliance on wound care Previous foot surgery / trauma Edema unilateral vs bilateral Dr. V. Singh Chauhan

35. Examination 1. General 2. Vascular examination Palpation of pulses Dorsalis pedis , posterior tibial , popliteal , femoral Venous filling time Colour changes Cyanosis , erythema Presence of edema Skin changes consistent with ischemia Skin atrophy Nail atrophy Abnormal wrinkling Decreased pedal hair Dr. V. Singh Chauhan

36. Vascular Assessment of peripheral pulses of paramount importance If any concern, vascular assessment ABI (n>0.45) Sclerotic vessels Toe pressures (n>40-50mmHg) TcO 2 >30 mmHg Expensive but helpful in amp. level Dr. V. Singh Chauhan

37. 3. Neurological examination Vibration perception -Tuning fork 128 cps Light pressure : Simmes – Weinstein 10 gram monofilament Light touch Two point discrimination Pain – pinprick Temperature perception: hot and cold Deep tendon reflexes Clonus , Babinki , rhombergs test. Dr. V. Singh Chauhan

38. Musculo -skeletal Examination Orthopaedic deformities: Hammer toes, flat feet Gait abnormalities Muscle group atrophy Plantar pressure assessment: computerized, Harris ink mat Dr. V. Singh Chauhan

39. Dermatological Examination Skin appearance: colour , texture, dry Calluses Fissures Nail appearance + Hair Tinea pedis Dr. V. Singh Chauhan

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41. Foot Wear Examination Type of shoe Fit Lining of shoe Foreign bodies in the shoe. Dr. V. Singh Chauhan

42. Diagnostic Workup FBS/RBS Glycosylated hemoglobin (HbA1C) FHG + ESR Wound and Blood cultures Serum Chemistry: CRP Urinalysis Dr. V. Singh Chauhan

43. Imaging Plain X-rays - Osteomyelitis , fractures - Soft tissue gas - Dislocations in neuropathic arthropathy CT Scan MRI Dr. V. Singh Chauhan

44. Classification Modifications to classification being done Commonest Meggit - Wagners University of Texas Dr. V. Singh Chauhan

45. Meggit - Wagners Classification 0 - Intact Skin (Impending ulcer/foot at risk) 1 - Superficial Ulcer 2 - Deep ulcer to bone/tendon/ligaments 3 - Osteomyelitis 4 - Localised Gangrene – toes/ forefoot 5 - Extensive Gangrene Dr. V. Singh Chauhan

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47. Advantages Simple Higher grades related to increased risk of amputation Provides a guide to planning treatment Disadvantages Location and size of ulcer not evaluated Neuropathy status not evaluated Doesn’t take into account ischaemia & infxn Dr. V. Singh Chauhan

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49. University of Texas Classification Used in many clinical trials & Diabetic foot centres Uses 4 grades each of which is modified Infxn Stage B Ischemia Stage C Both Stage D Dr. V. Singh Chauhan

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51. Advantages Shows greater association with outcome of an ulcer/healing/amputation compared to Wagners Provides a guide to Rx Disadvantages Location and size of ulcer not evaluated Neuropathy status not evaluated Dr. V. Singh Chauhan

52. Treatment Multidisciplinary Approach Careful Evaluation of Diabetic foot Patient Education & Good Glycemic Control Wound Care – Obtain closure ASAP Dr. V. Singh Chauhan

53. Cellulitis Mild cellulitis – oral antibiotics Re-evaluation needed in 24-48hrs (marker). If it worsens – Change antibiotic / hosp admission. Dr. V. Singh Chauhan

54. Ulcers Xtics of ulcer need to be recorded Location / Size / Color of wound / wound margin xtics (rimming, undermining) Xtics of exudate Type / Amount / color / consistency / adherance to ulcer bed Dr. V. Singh Chauhan

55. Deeper ulcers may need debridement Trt with IV antibiotics based on swab culture Non operative mx Shoe modification To px formation of ulcer – custom insoles / wide shoes Total Contact Cast Relief of pressure by distributing stresses over large area Dr. V. Singh Chauhan

56. Wound care Goals – Provide moist environ, absorb exudate , act as a barrier & offload pressure at ulcer Endogenous growth factors such as platelet derived GF, transforming GF B, Epidermal growth factors now being used to accelerate wound healing Recombinant Human Platelet derived growth factor now approved in spain Dr. V. Singh Chauhan

57. Operative Debridement Mechanical ( washing+Suction ) + Surgical Autolytic + enzymatic Various occlusive & Semi occlusive dressings Antibiotics Dr. V. Singh Chauhan

58. Abscess & Osteomyelitis IND and debride to remove necrotic & infective tissues May be followed by reconstruction. Amputation may be needed to remove a chronic nidus of infxn and to get to the level of protective sense for prosthesis Dr. V. Singh Chauhan

59. Abscess & Osteomyelitis Role of Antibiotics Syst antibiotics may be less effective for necrotic bone where biofilm formation impairs penetration However Acharya S, Soliman A. Conservative mx of diabetic foot osteomyelitis . Diabetic Res Clin Pract . 2013 Sep; 101(3) 66.9% healed with antibiotics alone (retrospective study) Senneville E, Lambert A. Outcome of diabetic foot osteomyelitis treated non surgically for OM of foot: A retrospective study. Diabetic care. 2008 Apr 31(4); 637-41 Bone culture based antibiotic therapy is a factor predictive of success in diabetics treated non surgically (Compared centres with facilities for bone biopsy against those without) Dr. V. Singh Chauhan

60. Gangrene Can present as dry / wet or necrotising fascitis Indications Uncontrolled infxn / sepsis Non ambulatory pt with fxionally useless limb Wet gangrene Patient’s request Dr. V. Singh Chauhan

61. Amputations need proper ix and pt counselling Avoid distal amputations if non invasive vascular studies show poor vasculature Ankle brachial index (>0.5) - n Absolute toe pressure (>45mmhg) - n Transcutaneous partial pressure of O2 (>30mmHg) Pts nutritional status needs evaluation Albumin > 2.5g/dl Total Protein >6g/dl Good lymphocyte count Wound closure depends on infection and adequacy of bleeding. If not sufficient – staged Dr. V. Singh Chauhan

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63. Types of minor amputations Dr. V. Singh Chauhan

64. Attempt minor amputation at 1 st sitting (if possible) When major amputation done, mortality rate increases Evans K et al. The importance of limb preservation in the diabetic population. J Diabetic Complications. 2011 Jul-Aug; 25(4) 227-31 80% of minor amputees alive after 2yrs, 73% of them preserving the limb, 64% fully ambulant In the BKA group – 52% died within 2yrs, 64% ambulant on prosthesis Dr. V. Singh Chauhan

65. Izumi Y et al. Mortality of 1 st time amputees in diabetes: a 10yr observation. Diabetes Res Clin Pract . 2009 Jan; 83 (1):126-31 Difference in mortality being 1.6 times > in major amputees compared to ray amputations Dr. V. Singh Chauhan

66. Do not forget Vascular Mx Single vessel angioplasty to multiple bypass arterial procedures Mx of deformities Charcots arthropathy Balancing of muscle forces e.g achilles tendon lengthening in tight heel cord Need for plastic surgeons Orthotics & Special shoes Neuropathy control Good glycemic control Analgesics & other neuropathy agents Dr. V. Singh Chauhan

67. ; Have a Diabetic feet free day Dr. V. Singh Chauhan