Clinical examination and risk classification of the diabetic foot

Abstract

Foot ulceration is one of the most common precursors to lower extremity amputations among persons with diabetes (Singh et al., JAMA. 2005; 293(2):217-28; Boulton and Vileikyte, Wounds. 2000; 12(Suppl B):12B-8; Reiber et al., Rehabil Res Dev. 2001; 38(3):309-17). Ulcerations are pivotal events in limb loss for two important reasons. They allow an avenue for infection (Armstrong and Lipsky, Diabetes Technol Ther. 2004; 6:167- 77), and they can cause progressive tissue necrosis and poor wound healing in the presence of critical ischemia. Infections involving the foot rarely develop in the absence of a wound in adults with diabetes, and ulcers are the most common type of wound in this population (Armstrong and Lipsky, Diabetes Technol Ther. 2004; 6:167-77). Foot ulcers, therefore, play a central role in the causal pathway to lower extremity amputation (Pecoraro et al., Diabetes Care. 1990; 13:513-21). The etiology of ulcerations in persons with diabetes is commonly associated with the presence of peripheral neuropathy and repetitive trauma due to normal walking activities to areas of the foot exposed to moderate or high pressure and shear forces (Armstrong et al., J Foot Ankle Surg. 1998; 37(4):303-7). Foot deformities, limited joint mobility, partial foot amputations, and other structural deformities often predispose diabetics with peripheral neuropathy to abnormal weight bearing, areas of concentrated pressure, and abnormal shear forces that significantly increase their risk of ulceration (Cavanagh et al., Diabet Med. 1996; 13 Suppl 1:S17-22; Lavery et al., Diabetes Care. 1996; 19(8):818-21; Diabetes Care. 1995; 18(11):1460-2). Brand (The diabetic foot. In: Diabetes mellitus, theory and practice. Medical Examination) theorized that when these types of forces were applied to a discrete area over an extended period they would cause a local inflammatory response, focal tissue ischemia, tissue destruction, and ulceration. Clearly, identification of persons at risk for ulceration is of central importance in any plan for amputation prevention and diabetes care.