One possible complication of Diabetes is called Charcot Neuroarthropathy, Charcot for short. This is a condition in which the structure of the foot collapses due to breakdown of the bones and ligaments. The disease process is not well understood, even to this day. However, what is well understood about Charcot is that it places patients at a much higher risk of ulceration due to deformity that results after an episode of Charcot.
In its earliest phase, there is a large amount of inflammation. The foot is red, hot, swollen, yet in many cases (due to neuropathy) it is not painful. In the second phase of a Charcot flare, coalescence, the bone fractures that occurred in the first phase begin to heal back together. The third phase is consolidation of these bone fractures and remodeling.
In the first phase, immobilization and protection from stress on the foot is critical to prevent excessive deformity of the foot. If this is not accomplished successfully, a so-called "rocker bottom" deformity results, which predisposes a person to abnormal stress and strain on the foot leading to ulcerations.
Charcot does not only occur in diabetes, but in other neuropathic conditions associated with syphilis, alcoholic neuropathy, cerebral palsy and spinal cord injuries (to name a few). If you have experienced neuropathy and notice a sudden swelling and redness in the foot, see your podiatrist as soon as you notice these symptoms. The sooner this is addressed, the better the outcome!