The trifecta of Diabetic foot ulceration

The triage of
 Neuropathy,
Arterial disease 
& Mechanical stress (pressure or shear and friction)

 is well-accepted as necessary for the development of ulceration in the diabetic foot. The roles of neuropathy and peripheral arterial disease will not be discussed in this chapter as they are the focus of other chapters in this book. 
For the purpose of this discussion, it will be assumed that the reader understands that biomechanical abnormality alone is not a sufficient cause for ulceration.

 Neuropathy, peripheral arterial disease, or a combination of both, is necessary for abnormal mechanical stress to precipitate ulceration. With this fact in mind, it is important to acknowledge the role of foot biomechanics in precipitating ulceration, as it is clearly important and yet frequently ignored.
 Biomechanical abnormality alone does not cause foot ulceration.
 • Patients with rheumatoid arthritis rarely develop foot ulceration despite gross foot deformities.
 Combination of neuropathy, arterial disease and bio-mechanical abnormality are necessary to precipitate foot ulceration