Charcot Osteoarthropathy, also known as Charcot foot, is a destructive but often painless condition that affects the bones, joints, and soft tissues of the foot or ankle in a diabetic person. It is a breakdown of the foot bones that is initiated by nerve damage (neuropathy). When sufficiently weakened, the bones fracture and the joints in the ankle or foot dislocate. Because the person has numbness in the feet, they are unaware of the extent of the damage and continue to bear body weight, causing further trauma and damage to the affected foot. Over time, this will eventually cause the entire foot to become visibly deformed.
While most commonly linked to diabetes, nerve damage can also be caused by other factors including history of infection, alcohol or drug use, genetics, autoimmune diseases, HIV, Parkinson’s disease, and trauma to the spinal cord and major nerves.
Leaving a Charcot foot untreated can lead to open sores on the bottom of the deformed foot due to excessive pressure on bony prominences. This is particularly dangerous as such sores can develop into bone infections which often result in foot or lower limb amputations. This is a particular danger for diabetics or others with compromised immune systems as the infections are more likely to spread or increase the risk of death.
Even without foot ulcers, patients will quickly lose mobility with the dysfunctional foot shape and be more prone to falls. Patients become at high risk for subsequent complications.
Acute Charcot foot requires immediate offloading by reducing or minimizing the weight that is put on the foot. Offloading should be done as soon as possible to halt the deformity and is performed by a podiatrist casting or immobilising the foot.
Once the condition has been stabilised, the foot can be offloaded using more discreet methods of casting including full custom orthotics and custom ankle foot orthotics (AFO). AFOs are designed to protect the foot and ankle by supporting and protecting the weakened bones while they heal. AFOs have also been found to be highly effective at promoting healing of pressure ulcers of the foot.1
Chronic Charcot foot with deformity can be offloaded using orthotics and AFOs without the need for strict casting protocols as the deformity has already occurred.
If Charcot foot is detected early enough, intervention can be carried out to stop the progression of the deformity. If the structure of the foot is sufficiently compromised, doctors may also recommend for a surgical reconstruction or even amputation. Consulting a podiatrist earlier for advice and treatment can help to prevent this late stage scenario.
1 Landsman AS, Sage R. Off-loading neuropathic wounds associated with diabetes using an ankle-foot orthosis. J Am Podiatr Med Assoc. 1987; 87(8):349-57.