Two mechanisms make diabetic feet vulnerable. Peripheral neuropathy — nerve damage from chronic hyperglycemia — eliminates the pain signal that normally alerts a person to injury. A patient with significant neuropathy can walk on a nail for days without knowing it. Peripheral arterial disease (PAD) — reduced blood flow from atherosclerosis — impairs the healing response. Without adequate circulation, even a small wound cannot close.
The annual diabetic foot exam is a standard of care requirement, not optional. It should include monofilament testing (10g Semmes-Weinstein filament at 9 standardized sites to detect loss of protective sensation), ankle-brachial index (ABI) to assess arterial flow, pulse assessment, skin and nail inspection, and footwear evaluation. Patients with loss of protective sensation (LOPS) should be examined at every clinical visit.
Preventive footwear is an underutilized intervention with strong evidence. Therapeutic shoes and custom insoles reduce ulcer recurrence rates significantly. Patients should be instructed: never walk barefoot, inspect feet daily (including the soles — use a mirror if needed), dry between toes, keep skin moisturized but not between the toes, and avoid heating pads or hot water that can burn insensate skin.
When an ulcer does develop, it requires structured assessment (Wagner grading, infection evaluation, probe-to-bone testing for osteomyelitis), offloading (Total Contact Cast is gold standard for plantar ulcers), and wound care. The 40% wound area reduction at 4 weeks is a validated healing benchmark — failure to meet it mandates reassessment of vascular status, infection, nutrition, and glycemic control.