Foot structure and footwear prescription in diabetes mellitus.

Foot structure abnormalities such as foot deformity and limited joint mobility are common and well established components of the diabetic foot which are associated with increased levels of mechanical stress on the foot and the development of ulcers. Our understanding of foot structure abnormality in diabetes has improved recently, mainly through the findings from in vivo imaging studies. Several examples will be discussed in this review. A limited understanding, however, still exists about several aspects related to the assessment, etiology, and consequences of change in foot structure in diabetes. Knowledge on these matters is needed if we are to better deal with the implications of foot structure change in diabetes. Diabetic patients with neuropathy and foot deformity are commonly prescribed with custom footwear, in particular after ulcer healing. The goal of this footwear is to redistribute and reduce plantar foot pressures, and to prevent ulcer recurrence. However, the available evidence for the effectiveness of custom footwear in secondary ulcer prevention is not yet strong. This may be associated with several factors, including a lack of standardized or systematic approach (a set of guidelines) in footwear prescription and evaluation or with the significant variability that exists across patients in the offloading effect of different footwear interventions, which increases the difficulty of predicting what works for a given patient. Objective evaluation tools such as in-shoe plantar pressure analysis can be helpful in this regard in order to ensure efficacy of an intervention. This provides a more optimal footwear solution that may lower the risk for ulceration.