Diabetic Charcot Foot

Charcot neuroarthropathy, often referred to as Charcot Foot, is an uncommon but devastating disorder of the bones and joints in the foot and ankle.  Most commonly Charcot Foot is seen in diabetic patients with neuropathy, but it has also been described in patients with neuropathy of other causes.

Charcot foot is characterized most frequently as a red, hot, swollen foot.  It is typically painless, as the patient is neuropathic.  Charcot foot is often misdiagnosed as gout, cellulits, or deep venous thrombosis (DVT).  This usually happens in a primary care or emergency setting, where the clinician may not have a high suspicion for Charcot foot.  The consequences of a missed diagnosis or delayed treatment include a bony deformity, which can lead to ulceration and subsequent infection.  Thus, early diagnosis and initiation of treatment by a trained foot and ankle specialist is essential. 

The “rocker-bottom” deformity is typical of Charcot foot that has affected the midfoot, as is the case with the majority of patients.  This refers to an increased convexity of the bottom of the foot that is the result of excessive midfoot collapse.  When this happens, bone can protrude, which causes increased areas of pressure on the skin.  This increased pressure leads to ulceration if not addressed.

The pathophysiology of Charcot foot has been debated in the past, however current practitioners generally agree on the cause as a combination of neurovascular dysregulation and trauma to the foot or ankle as the inciting event.  The neurovascular dysregulation causes increased blood flow to the feet, which can “wash out” some of the bone density, making the bones and joints of the foot susceptible to injury.  Trauma may be in the form of a singular acute event, such as a fracture, but may also be from repetitive microtrauma from a previously existing foot deformity or a poorly fitting pair of shoes or a sudden increase in activity.  The uncontrolled inflammation associated with Charcot foot causes an increase in osteoclast activity, the cells responsible for degrading bone. 

Diagnosis of Charcot foot is made mostly as a clinical diagnosis.  The foot will appear red, hot, and swollen, and there may be a significant temperature difference between the feet.  X-rays are taken, but may only show subtle changes in bone quality and joint alignment if it is very early in the disease.  MRI can also be used to examine the bones and joints of the foot or ankle, but is not necessarily diagnostic of Charcot foot.  This is because the Charcot foot may look very similar to osteomyelitis, or an infection of the bone.  However, the information provided by imaging studies such as x-rays and MRI can help the clinician in diagnosing Charcot foot.

The most important aspect of treatment for Charcot foot is offloading of the affected foot.  This means that there is no weight placed on the foot.  This can be done by casting with either plaster or with a removable cast.  Some patients may be able to use crutches or a walker while the cast is on, however, for many patients a wheelchair is recommended.  This is due to the fact that excessive pressure on the unaffected site may lead to increased trauma to that side, thus possibly initiating a Charcot foot on the other side.  Approximately 30% of patients affected by Charcot foot will go on to develop Charcot foot on the opposite side. 

Medical treatment with bisphosphonates, drugs traditionally used to treat osteoporosis and some other disease of bone, has shown to be of some benefit to patients in some small study groups.  These drugs may include pamidronate (Aredia) or alendronate (Fosamax).  Treatment with intranasal calcitonin spray has also been used.  Calcitonin is a naturally occurring hormone that helps to regulate calcium and bone density in the body.  Additionally, some doctors have used anti-inflammatory medications in an effort to restrict some of the uncontrolled inflammation associated with Charcot foot. 

Surgical treatment can also be used to help patients with Charcot foot.  For patients with advanced deformities related to Charcot foot, surgery can be used to establish a more normal appearing foot, which can then be placed in a customized shoe or Charcot restraint orthotic walker (CROW).  The goals of surgery on the Charcot foot are to heal any current ulcers, prevent future ulceration and infection, and to fit the patient to a customized device.  These devices are generally worn by a patient with Charcot foot at all times, and are considered to be lifelong devices. 

Charcot foot continues to be an area of interest and research for many podiatric surgeons, and is an extremely debilitating and devastating syndrome.  The patients who develop Charcot foot need a lot of attention and counseling regarding their foot deformity, and adherence to medical and surgical treatment plans is essential for healing and for positive outcomes.  Charcot foot remains a difficult problem to treat, however, advances in the understanding of the syndrome and advances in technology have made for better outcomes. 

Central Florida Foot & Ankle Center, LLC 
101 6th Street N.W. 
Winter Haven, FL 33881 
Phone: 863-299-4551 
www.FLFootandAnkle.com