Introduction
Foot complications are among the most serious and costly complications of diabetes mellitus. Amputation of the lower extremity or part of it is usually preceded by a foot ulcer. A strategy that includes prevention, patient and staff education, multidisciplinary treatment of foot ulcers, and close monitoring can reduce amputation rates by 49–85%. Therefore, several countries and organizations, such as the World Health Organization and the International Diabetes Federation, have set goals to reduce the rate of amputations by up to 50%.
The basic principles of prevention and treatment described in these guidelines are based on the International Consensus on the Diabetic Foot. Depending on local circumstances, these principles have to be translated for local use, taking into account regional differences in socio-economics, accessibility to health care, and cultural factors. These practical guidelines are aimed at healthcare workers involved in the care of people with diabetes. For more details and information on treatment by specialists in foot care, the reader is referred to the International Consensus document.
Pathophysiology
Although the spectrum of foot lesions varies in different regions of the world, the pathways to ulceration are probably identical in most patients. Diabetic foot lesions frequently result from two or more risk factors occurring together. In the majority of patients, diabetic peripheral neuropathy plays a central role: up to 50% of people with diabetes with type 2 diabetes have neuropathy and at-risk feet.
Neuropathy leads to an insensitive and sometimes deformed foot, often with an abnormal walking pattern. In people with neuropathy, minor trauma – caused, for example, by ill-fitting shoes, walking barefoot, or an acute injury – can precipitate a chronic ulcer. Loss of sensation, foot deformities, and limited joint mobility can result in abnormal biomechanical loading of the foot. Thickened skin (callus) forms as a result. This leads to a further increase of the abnormal loading and, often, subcutaneous haemorrhage.
Whatever the primary cause, the patient continues walking on the insensitive foot, impairing subsequent healing (Figure 1). Peripheral vascular disease, usually in conjunction with minor trauma, may result in a painful, purely ischaemic foot ulcer. However, in patients with both neuropathy and ischaemia (neuro-ischaemic ulcer), symptoms may be absent, despite severe peripheral ischaemia. Microangiopathy should not be accepted as a primary cause of an ulcer.