Expert Insights On Treating The Wounded Charcot Foot
Treating a wound on a Charcot foot can be a challenge. Our expert panelists discuss the diagnosis of acute Charcot, the management of Charcot and Charcot-related wounds, indications for exostectomy and keys to facilitating a return to weightbearing.
Q: How do you diagnose an acute Charcot foot? Do you use any ancillary testing?
A: Most of the time, Geoffrey Habershaw, DPM, diagnoses acute Charcot by combining the patient’s history and physical with simple tests.
Dr. Habershaw, Lawrence Lavery, DPM, and David G. Armstrong, DPM, PhD, cite swelling and temperature changes as signs of Charcot. Dr. Habershaw says crepitus, deformity, swelling and warmth “pretty much clinch” the diagnosis of Charcot. He adds that plain X-rays with the aforementioned physical findings will confirm Charcot. Dr. Habershaw says a triphasic bone scan will confirm micro-fracture and ligamentous damage. In this clinical scenario, he rarely uses magnetic resonance imaging (MRI).
For Dr. Lavery, the diagnosis starts with a high index of suspicion. He notes that Charcot patients have unilateral edema along with trauma that is mild, incidental or unknown. Such patients will have numbness, tingling and formication, according to Dr. Lavery. He says these patients feel their feet are thick as if they have a sock or mud stuck to the bottom of their foot. He says a thorough sensory examination with monofilaments will reveal diminished pressure sensation and an abnormal vibration perception threshold. Dr. Lavery notes that temperature assessment will usually reveal the affected foot has an increase in temperature of 4 to 10º F in comparison to the other foot. He advises checking radiographs to ensure the patient does not have a fracture or dislocation.
Dr. Armstrong notes that Charcot’s arthropathy of the foot is a diagnosis of exclusion.
“A profoundly and globally red, hot, swollen foot in a neuropathic patient in the absence of other causes should be considered Charcot arthropathy until suggested otherwise,” maintains Dr. Armstrong.
Likewise, Lawrence Karlock, DPM, says when a patient presents with a warm, red, swollen diabetic neuropathic foot with a closed soft tissue envelope, one should consider it a Charcot foot until proven otherwise. He says one must rule out other differential diagnoses of cellulitis and gout.
In a patient with neuropathy, new, unilateral pedal edema will rule out Charcot in the differential diagnosis, according to Dr. Habershaw.
Q: What wounds do you commonly see in the Charcot foot or ankle?
A: Dr. Habershaw says classic midfoot Charcot and Charcot in the Lisfranc joint may lead to ulceration either below the first metatarsocuneiform joint or below the cuboid. When there is rearfoot Charcot or Charcot in the Chopart joint, Dr.
Habershaw says the wound will be proximal to the cuboid. In Dr. Lavery’s experience, the most common wound site with Charcot is over the cuboid.
Dr. Karlock agrees. He says it is common to see a midfoot Charcot foot present with a plantar first MPJ ulcer medially or with a subcuboid ulcer laterally. He notes the Charcot ankle will present with a varus deformity and a lateral malleolus ulcer.
In regard to subtalar or ankle Charcot, Dr. Habershaw says one will see ulcerations either medial or lateral on the foot and ankle depending on which way the foot drifts. With a medial foot drift, one will see a lateral ulceration whereas a lateral foot drift may lead to medial ulceration, according to Dr. Habershaw.
Dr. Armstrong notes that approximately 40 percent of people with Charcot arthropathy will present with a concomitant wound. He adds that about 80 percent of those wounds associated with Charcot arthropathy are in the midfoot.
Q: How do you manage the acute and chronic Charcot deformity, and its wounds?