A 49-year-old woman comes to the physician for a 2-month swelling of her right foot. There is no history of trauma and she does not report fever or pain. She has a 30-year history of type-I diabetes mellitus. Physical examination shows swelling of the right forefoot. There are no overt ulcerations. There is decreased sensation to touch, propioception, and pain below the ankles bilaterally. X-ray of the ankle shows disorganization and disruption of the tarsometatarsal joints. Which of the following is the most likely cause of these findings?
Arterial insufficiency
Non-enzymatic glycosylation
Lack of normal joint sensation
Vasculitis
Venous insufficiency
