Managing Charcot Foot: An Underdiagnosed Condition in Patients With Diabetes
Charcot foot, also known as neuropathic osteoarthropathy, affects the bones, joints, and soft tissues of the foot and ankle. It is a significant complication of diabetes that can result in amputation, but it is commonly missed. During a symposium at the ADA meeting, a panel of world-renowned experts described this clinically challenging condition and the benefits of early diagnosis.
According to one of the presenters, William J. Jeffcoate, MRCP, Foot Ulcer Trials Unit, department of diabetes and endocrinology, Nottingham University Hospitals Trust, although there is no singular cause for the development of Charcot foot, there are factors that predispose individuals to its development, as well as precipitating factors. “Neuropathy is a prerequisite, and then there is an often-recognized trigger,” said Jeffcoate, who cited a 2012 study in Diabetologia by Game and colleagues that found that 36% of patients experienced trauma to the foot in the preceding 6 months, with 12% having had surgery to the affected foot. Another 35% had an ulcer on the affected limb, with 20% of these individuals having osteomyelitis.
Crystal Murray Holmes, DPM, CWS, clinical assistant professor of medicine, University of Michigan Medical School, emphasized that Charcot foot can be prevented if recognized early, but that it goes undiagnosed by the referring physician 95% of the time. She cited a 2011 study in Diabetic Medicine by Wukich and associates that showed Charcot foot diagnosed at more than 8 weeks had a 67% complication rate, whereas Charcot foot identified within 4 weeks had a complication rate of only approximately 14%. Because the condition is so challenging to diagnose, particularly in nonpodiatric settings, Holmes outlined seven practical clinical pearls that can facilitate diagnosis of Charcot foot:
1. Know that you can affect patient outcomes
2. Maintain a high index of suspicion
3. Add Charcot foot to your list of differential diagnosis
4. Recognize stage 0 (see stages in the Table)
5. Use histology to confirm Charcot foot
6. Magnetic resonance imaging is better than radiographs for diagnosing stage 0
7. Use multiple modalities to assist in diagnosis
When a patient has a red, hot, swollen foot that has peripheral neuropathy, Charcot foot is a diagnosis that needs to be considered, she said. She also noted that clinicians need to be aware of the risk factors for Charcot foot, which include obesity, peripheral neuropathy, older age, diabetes duration of 6 years or longer, hemoglobin A1c levels of 7% or higher, renal failure, arthritis, and anemia. She noted that two additional risk factors, osteopenia in type 1 and type 2 diabetes and end-stage renal disease, are especially common in the setting of renal transplant and renal pancreatic transplant, and also increase the risk of Charcot foot.
If left untreated, Charcot foot increases the likelihood for foot and ankle ulceration, which can lead to an infection and amputation. George Liu, DPM, FACFAS, assistant professor, University of Texas Southwestern Medical Center, proceeded to discuss the management of Charcot foot. He noted “ulceration is the pivotal event that allows a patient to be at risk for a limb loss.”
The consensus for initial treatment of acute Charcot foot is nonoperative treatment with strict nonweight-bearing immobilization to prevent further deformity, he said; however, sometimes conservative management is not enough, he warned. Surgical intervention is indicated for nonplantigrade, unstable, deformed feet and ankles, as rigid deformities cannot be offloaded and unstable deformities cannot be braced. Liu said the goal of surgery is a stable, plantigrade, braceable limb that is ulcer-free. If this is achieved, “I think you have achieved success,” he said.—Eileen Koutnik-Fotopoulos
