Diabetic foot complications are a major source of morbidity and health care costs. They result from a complex interplay of ischemia, ulceration, infection, and Charcot's joint due to diabetes-related changes. Hyperglycemia leads to nonenzymatic glycosylation of proteins and tissues, formation of advanced glycosylation end products, and accelerated atherosclerosis. This causes peripheral vascular disease, neuropathy, and foot deformities which impair sensation and blood flow, making the feet susceptible to infection, ulceration, and gangrene. Charcot's joint is a destructive foot arthropathy caused by loss of sensation from diabetic neuropathy.

1. Diabetic Foot

3. Pathogenesis of Chronic Complication of diabetes mellitus

4. Hyperglyceamia Nonenzymatic glycosylation of collagen and other proteins in interstitial tissue and blood vessel wall Formation of irreversible advanced glycosylation end products ( AGES ) ‏ Cause cross link between polypeptides Trap plasma and interstitial proteins including LDL Promote the deposition of cholesterol in the blood vessel intima Accelerated the process of atherogenesis Formation of atherosclerotic plaque Atherosclerosis

5. Glucose Sorbitol Fructose NADPH + H + NADP + NAD + NADH + H + Aldose reductase Polyol dehydrogenase Disturbance in polyol pathway GSH (reduced) GSSG (oxidized) Glutathione reductase

6. Hyperglycaemia  stimulate polyol pathway   accumulation sorbitol + fructose in Schwann cells Increase IC osmolality  influx of water  osmotic cell injury  damage schwann cell (demyelination )  axon degeneration irreversibly  disrupt neural function  Diabetic neuropathy

8. a) Predisposing peripheral vascular disease Atherosclerosis (medium-sized vessels below the knee) Compromised blood supply Coagulative necrosis Dry gangrene Infection Wet gangrene Ischemia Ulcer

9. Predisposing peripheral vascular disease Artheroma plaque narrowing the arterial lumen Ischaemic toes due to artherosclerosis

10. b) Neuropathy Neuropathy Motor Sensory Autonomic ↓ nociception ↓ Proprioception, Unawareness of foot position Reduced sweating Dry skin Fissures and cracks Muscle wasting Foot weakness Postural deviation Deformities, stress and shear pressures Trauma Stress on bones & joints Plantar pressure Callus formation Infection Ulcer

12. Claw toe Severe atrophy of the intrinsic foot muscles (lumbrical & interossei) ‏ d/t motor neuropathy resulted in imbalance of foot muscles & cocked-up toes.

18. Clinical presentation of diabetic foot

19. Diffentiation of Ischaemic and Neuropathy Ulcer Painless Sites of pressures (metatarsal heads, heels) Painful At the distal and over bony prominences Ulceration Warm palpable pulses Cold Pulseless Palpation High arch + clawing of toes No trophic changes Surrounded by callus Dependent rubor Trophic changes Gangrenous digits Inspection Usually painless Or painful neuropathy Claudication Rest pain Symptoms Neuropathy Ischaemia

20. Ischemic foot ulcer

21. Neuropathic foot ulcer Callus formation on its surrounding ulcer lesion.

23. Charcot Joint Rocker bottom charcot foot