Etiology, pathophysiology and classifications of the diabetic Charcot foot

In people with diabetes mellitus, the Charcot foot is a specific manifestation of peripheral neuropathy that may involve autonomic neuropathy with high blood flow to the foot, leading to increased bone resorption. It may also involve peripheral somatic polyneuropathy with loss of protective sensation and high risk of unrecognized acute or chronic minor trauma. In both cases, there is excess local inflammatory response to foot injury, resulting in local osteoporosis. In the Charcot foot, the acute and chronic phases have been described. The former is characterized by local erythema, edema, and marked temperature elevation, while pain is not a prominent symptom. In the latter, signs of inflammation gradually recede and deformities may develop, increasing the risk of foot ulceration. The most common anatomical classification describes five patterns, according to the localization of bone and joint pathology. This review article aims to provide a brief overview of the diabetic Charcot foot in terms of etiology, pathophysiology, and classification.