This condition, which most often occurs as a complication of long-term diabetes, is a progressive degenerative condition that affects the foot. It is characterized by nerve damage in the foot along with severely weakened foot
bones. This combination can result in a person fracturing the foot, but continuing to walk on the broken bones, which leads to debilitating foot deformity.

This condition is almost always caused by nerve damage that results from diabetes, but it can result as a complication of any disease, syndrome or injury that damages the nerves of the feet. The loss of sensation in these nerves causes problems with the muscles that support the foot. A person with this type of nerve damage may adopt an improper stance or gait, placing harmful stress on the bones and joints of the foot. The bones begin to degenerate and fracture easily, leading to deformity.

There are three stages of the condition. During the first stage, the foot joint and surrounding bones break down, and the foot becomes unstable. The bones and joint can shift, causing foot deformity. During the second stage, the destructive process slows down and the foot begins to heal. The third stage of the condition results in the bones hardening in their new position, causing lasting foot deformity.