Risk stratification and pathophysiology: 1) IWGDF (International Working Group on Diabetic Foot) risk categories - Category 0: no neuropathy or PAD (annual screening); Category 1: neuropathy without deformity (6-monthly); Category 2: neuropathy with deformity or PAD (3-4 monthly); Category 3: history of ulcer or amputation (1-3 monthly); 2) Pathogenesis - peripheral neuropathy (sensory, motor, autonomic) leads to loss of protective sensation, foot deformity (claw toes, Charcot foot), dry skin with fissures; peripheral artery disease (PAD) reduces healing capacity; trauma from footwear, foreign objects, burns initiates injury; impaired immune function and hyperglycemia delay healing; 3) Charcot neuroarthropathy - progressive non-infectious destructive arthropathy in neuropathic foot, often misdiagnosed as cellulitis; midfoot collapse leads to rocker-bottom deformity and ulceration; 4) Foot deformities - hallux valgus, hammer toes, prominent metatarsal heads, equinus contracture, post-amputation altered mechanics increase pressure points; 5) Vascular - PAD diagnosed by ABI <0.9, toe pressure <30 mmHg, TcPO2 <30 mmHg suggest critical limb ischemia.
Education, examination, and footwear: 1) Patient education - daily foot self-examination including visual inspection (mirror for plantar surface) and palpation; never walk barefoot; check shoes for foreign objects before wearing; wash feet daily and dry thoroughly especially between toes; moisturize but not between toes; cut nails straight across; do not perform bathroom surgery on calluses or corns; report any new lesion immediately; 2) Annual comprehensive foot examination - 10g monofilament test (4-10 sites), vibration testing (128 Hz tuning fork), Achilles reflex, dorsal pedis and posterior tibial pulses, ABI if PAD suspected, skin/nail/deformity inspection, footwear assessment; 3) Footwear principles - extra-depth shoes with rocker bottoms for high-risk patients, custom orthoses to redistribute pressure, never wear slippers or flip-flops outdoors, replace shoes every 6-12 months, professional fitting; 4) Therapeutic footwear in high-risk - off-loading footwear (post-op shoes, total contact casts for active ulcers), accommodative orthoses with custom inserts; reduce ulcer recurrence 50%; 5) Prophylactic surgery - tendon lengthening for equinus, exostectomy for prominent bones, claw toe correction in selected high-risk cases.
Multidisciplinary care and risk modification: 1) Multidisciplinary foot clinic - includes diabetologist, podiatrist, vascular surgeon, infectious disease, plastic surgery, orthotist, diabetic nurse educator; reduces amputation 50-85%; 2) Glycemic control - HbA1c <7% in most, individualized; tight control reduces neuropathy progression; 3) Cardiovascular risk factor management - statin, ACEi/ARB, antiplatelet (aspirin or clopidogrel), blood pressure <130/80; 4) Smoking cessation - critical, more than doubles amputation risk in PAD; 5) Vascular intervention - endovascular or surgical revascularization for critical limb ischemia, ABI <0.5, severe rest pain, non-healing ulcer; 6) Skin and nail care - regular podiatric debridement of calluses (reduces pressure 25%), nail cutting by professional in high-risk; 7) Specific high-risk groups - chronic kidney disease (especially dialysis) markedly increases risk and mortality; post-transplant patients; previous amputation; 8) Telemedicine and remote monitoring - thermal foot mats, smart insoles emerging for early ulcer detection; foot temperature differences >2.2°C predict ulceration; 9) Cost-effectiveness - prevention is cost-effective; structured programs save 2-5x cost of care.