A natural history and framework for managing diabetic foot ulcers

When treating diabetic foot ulcers it is important to be aware of the natural history of the diabetic foot, which can be divided into five stages: stage 1 - normal foot; stage 2 - high risk foot; stage 3 - ulcerated foot; stage 4 - infected foot; stage 5 - necrotic foot. This covers the entire spectrum of foot disease but emphasizes the development of the foot ulcer as a pivotal event in stage 3, demanding urgent and aggressive management. Diabetic foot wound care in all stages needs multidisciplinary management to control mechanical, wound, microbiological, vascular, metabolic and educational aspects. Achieving good metabolic control of blood glucose, lipids and blood pressure is important in each stage, as is educational control to teach proper foot care appropriate for each stage. Aggressive management of diabetic foot ulceration will reduce the number of feet proceeding to infection and necrosis and thus reduce the number of major amputations in diabetic foot patients.

Diabetic Foot Ulcers

When treating diabetic foot ulcers it is important to be aware of the natural history of the diabetic foot, which can be divided into five stages: stage 1, a normal foot; stage 2, a high risk foot; stage 3, an ulcerated foot; stage 4, an infected foot; and stage 5, a necrotic foot. This covers the entire spectrum of foot disease but emphasises the development of the foot ulcer as a pivotal event in stage 3, which demands urgent and aggressive management. Diabetic foot care in all stages needs multidisciplinary management to control mechanical, wound, microbiological, vascular, metabolic and educational aspects. Achieving good metabolic control of blood glucose, lipids and blood pressure is important in each stage, as is education to teach proper foot care appropriate for each stage. Ideally, it is important to prevent the development of ulcers in stages 1 and 2. In stage 1, the normal foot, it is important to encourage the use of suitable footwear, and to educate the patient to promote healthy foot care and footwear habits. In stage 2, the foot has developed one or more of the following risk factors for ulceration: neuropathy, ischaemia, deformity, swelling and callus. The majority of deformities can be accommodated in special footwear and as callus is an important precursor of ulceration it should be treated aggressively, especially in the neuropathic foot. In stage 3, ulcers can be divided into two distinct entities: those in the neuropathic foot and those in the neuroischaemic foot. In the neuropathic foot, ulcers commonly develop on the plantar surface of the foot and the toes, and are associated with neglected callus and high plantar pressures. In the neuroischaemic foot, ulcers are commonly seen around the edges of the foot, including the apices of the toes and back of the heel, and are associated with trauma or wearing unsuitable shoes. Ulcers in stage 3 need relief of pressure (mechanical control), sharp debridement and dressings (wound control), and neuroischaemic foot ulcers may need vascular intervention (vascular control). In stage 4, microbiological control is crucial and severe infections need intravenous antibacterial therapy, and urgent assessment of the need for surgical drainage and debridement. Without urgent treatment, severe infections will progress to necrosis. In stage 5, necrosis can be divided into wet and dry necrosis. Wet necrosis in neuropathic feet requires intravenous antibacterials and surgical debridement, and wet necrosis in neuroischaemic feet also needs vascular reconstruction. Aggressive management of diabetic foot ulceration will reduce the number of feet proceeding to infection and necrosis, and thus reduce the number of major amputations in diabetic patients.

What is the most effective way to reduce incidence of amputation in the diabetic foot?

Approximately 40-60% of all amputations of the lower extremity are performed in patients with diabetes. More than 85% of these amputations are precipitated by a foot ulcer deteriorating to deep infection or gangrene. The prevalence of diabetic foot ulcers has been estimated to be 3-8%. The complexity of these ulcers necessitates a multifactorial approach in which aggressive management of infection and ischemia is of major importance. For the same reason, a process-oriented approach in the evaluation of prevention and management of the diabetic foot is essential. Healing rates of foot ulcers are unknown with the exception of specialised centres where it is between 80-90%. The negative consequences of diabetic foot ulcers on quality of life include not only morbidity but also disability and premature mortality. Costs for healing ulcers are high and even higher for ulcers resulting in amputation, due to prolonged hospitalisation, rehabilitation, and need for home care and social service for disabled patients. Therefore, one of the most important steps to reduce cost in the management of the diabetic foot is to avoid amputations. A cost-effective management should not only be focused on the short-term cost until healing but also on the long-term cost, since foot ulcer and especially amputation are related to increased re-ulceration rate and lifelong disability. A multidisciplinary approach including preventive strategy, patient and staff education, and multifactorial treatment of foot ulcers has been reported to reduce the amputation rate by more than 50%.