The Charcot foot is a non-infective, destructive type of arthritis that affects between 1-2.5% of diabetics. The incidence of this arthritic process has increased recently due to patients with diabetes mellitus living longer. There is an equal distribution among males and females. The average age of patients developing a Charcot foot is 40 years. 30% of patients develop a Charcot foot in both feet and/or ankles. This form of arthritis can develop suddenly and without pain. In a very short period of time the bones in the foot and/or ankle can spontaneously fracture and fragment.

The final result in the development of a diabetic Charcot foot is severe foot deformity. These deformities may result in difficulty wearing standard footgear. As the deformity progresses the foot takes on the appearance of a "rocker bottom". As the arch of the foot collapses areas of pressure develop on the bottom of the foot that are prone to developing open sores or ulcerations. Loss of ankle stability may occur to such an extent that the patient may not be able to walk without the use of a brace. The vast majority of these deformities can be treated with non-operative care. New advances in technology and the development of new forms of lower extremity braces and splints have provided a wider range of treatment alternatives that are very effective in managing the Charcot foot.

There are situations where non-operative therapy is ineffective in managing a Charcot foot. Surgical management of the Charcot foot may be required to resolve some of the problems associated with the condition. Indications for surgery include: 1) chronic deformity with significant instability that is not amenable to brace treatment, 2) chronic deformity with increased plantar pressures and risk of ulceration, 3) a significant deformity with secondary ulceration that has failed to heal despite non-operative therapy and 4) recurrent ulcers that have initially healed with non-operative care.

Surgical Intervention

Various types of surgery are available and may be required to manage a Charcot foot. The type of surgery that may be necessary depends on 1) the anatomic location of the Charcot deformity (i.e. the midfoot, the ankle. etc.) 2) the stage of the Charcot process (there are three specific stages of the Charcot process) 3) whether or not an ulcer is present. 4) whether or not the deformity is unstable and 5) overall health status of the patient.

The types of surgical procedures include the following:

1.       Ostectomy - Ostectomy is a surgical procedure where a portion of bone is removed from the bottom of the foot. This procedure is usually performed for a wound on the bottom of the foot that is secondary to pressure from a bony prominence. An ulcer may or may not be present. The goal of the surgery is to remove the bone causing increased pressure and thereby allowing the ulcer to resolve or prevent the area from ulcerating. This procedure is usually performed as an outpatient or may require a one-night stay in the hospital. The type of anesthesia selected depends upon the health status of the patient and the preference of the surgeon. Recovery time includes 3-4 weeks in a weight-bearing brace or cast. A patient can usually return to extra depth footgear with a diabetic insert following complete healing.

2.       Midfoot Realignment Arthrodesis - This procedure is usually indicated when there is significant instability of the middle portion of the foot. Usually the foot has collapsed and there is significant bony prominence along the bottom of the foot. Surgery is indicated when a simple ostectomy will not be sufficient. The goal of surgery is to provide stability and a relatively normal arch to the foot. This procedure usually requires a one or two night stay in the hospital. This is usually performed under general anesthesia and requires various types of internal fixation to be placed within the foot. This may include screws and plates. The convalescence associated with midfoot realignment arthrodesis is approximately three months in a non-weight-bearing cast. A patient may then progress to a weight-bearing brace for approximately 1-2 months. The patient will then return to an extra depth shoe with a diabetic insert at 5-6 months following surgery.

3.       Hindfoot and Ankle Realignment Arthrodesis - Hindfoot and ankle realignment arthrodesis is usually indicated when there is significant instability resulting in a patient being unable to walk. These types of procedures are recommended when bracing has failed. Patients are basically non-ambulatory and many times amputation of the limb is the only other alternative. Realignment arthrodesis of the hindfoot and ankle is a limb salvage surgery. The ultimate goals of the procedure are to maintain a functional limb such that one can transfer within their home and possibly do some walking with the use of a brace or ambulatory assistive device. This procedure usually requires a 1-2 night stay in the hospital. The procedure is performed under general anesthesia and requires the use of various types of internal and external fixation devices. This may include the use of screws, plates, intramedullary nails and external fixators. The postoperative course includes approximately four months in a non-weight-bearing cast followed by a 2-3 month period of walking in a protective rocker bottom brace. A patient will then progress to a custom made brace that may be required throughout the course of their lifetime.

Possible Complications

Surgery in the diabetic patient always has significant risks. People with diabetes mellitus are more susceptible to infection due to their disease process. Therefore, these operations have a high complication rate. The arthrodesis procedures have a greater failure rate, increased risk of complications and longer convalescence relative to simple procedures such as ostectomy. It is recommended that a patient and their family have an extensive consultation with the surgeon to understand all potential risks including limb loss. A patient must be medically fit since this does require a general inhalation anesthesia and an extensive postoperative course. Preoperative work-up should include assessment of cardiac status and must be performed prior to surgical intervention.

Summary

Surgical management of the Charcot foot can be challenging and at times risky, but often the only alternative for limb-salvage. Many of the patients who undergo this type of surgery would otherwise go on to a below-the-knee amputation. Therefore, surgical management of the Charcot foot can be quite gratifying to the patient, the patient's family and the surgeon. The patient and the family should thoroughly understand the risks and benefits of the procedure and have an extensive preoperative consultation with the surgeon. It is recommended that surgery be performed by an experienced practitioner who has a thorough understanding of the disease process and experience with this type of surgery. It may be advantageous to have this type of surgery performed at a tertiary care facility to handle the potential complications that one might incur with these types of patients.