Charcot Foot
Charcot Foot neuropathy (also called Charcot neuroarthropathy) is a serious and progressive condition that affects people with significant nerve damage—most commonly those with diabetes-related peripheral neuropathy.
It leads to weakening of the bones and joints in the foot, which can cause fractures, joint dislocations, and severe deformities, often without significant pain. The condition was first described in 1868 by French physician Jean Martin Charcot. He noted its presence in patients with tabes dorsalis, a condition resulting from late complications of untreated syphilis that causes nerve damage and pain in the spinal cord and brain.
Who gets Charcot Foot?
Although Charcot foot is rare (affects between 0.1% to 0.9% of people with diabetes) it can cause destructive deformities of the foot which requires early and accurate diagnosis. Mostly Charcot occurs in diabetics but can occur in other conditions with the common link being neuropathy.
Causes and Risk Factors:
Diabetes (especially long-standing, poorly controlled) – most common cause.
Other causes:
Alcoholism, leprosy, spinal cord injury, or any condition causing peripheral neuropathy.
How does Charcot develop?
Pathophysiology: Charcot foot develops due to a combination of neuropathy, autonomic neuropathy, and an excessive local inflammatory response to minor trauma. This results in a vicious cycle of trauma, inflammation, and progressive bone and joint damage.
Two Theories:
Neurotraumatic Theory. Due to sensory neuropathy, patients don’t feel pain from microtrauma (e.g. sprains, fractures). They continue walking on the injured foot, causing repeated mechanical stress. This leads to progressive joint instability, fractures, and deformity.
Neurovascular Theory. Autonomic neuropathy leads to increased blood flow to peripheries. This causes increased osteoclastic activity and bone resorption, making bones fragile and prone to fractures.
Diagnosis and Complications of Charcot Foot:
Clinical signs: Swollen, warm, red foot (often seen in early stages). Charcot classification systems Eichenholz and Sanders & Frykberg (https://www.ncbi.nlm.nih.gov/books/NBK470164/).
Complications: Foot deformities such as flatfoot, rocker-bottom foot, bony deformities which can lead to ulceration, infection, and in some cases loss of limb (amputation) or life.
Recurrence of Charcot joint.
Imaging: X-rays, MRI, or bone scans to detect fractures, joint dislocations, or bone changes.
Why Correct Diagnosis is Important:
Often Charcot is misdiagnosed as other conditions such as gout, deep vein thrombosis, soft tissue injury, osteo/rheumatoid arthritis or infection (more often osteomyelitis). It is suggested that a lack of awareness of the condition and clear clinical and radiological diagnostic criteria lead to misdiagnosis. At early stages, it may be difficult to diagnose Charcot Foot since the X-ray and lab tests may be normal. Charcot is misdiagnosed 25% of the time which can cause a 7-month delay in the true diagnosis.
Incorrect diagnosis can lead to significant delays in appropriate treatment especially in the acute Charcot foot. Correct diagnosis and treatment are imperative to decrease permanent foot deformity and allow for a stable and plantigrade foot that is suitable for walking.
Treatment:
The aim of management in the acute phase is to halt the inflammatory process, relieve pain and minimise potential foot deformity. Total contact casting is one of the most effective pressure offloading and immobilisation devices to bring about bone healing and reduce inflammation.
Charcot neuropathy is a complex condition that often requires management from a team of professionals (i.e. GP, Podiatrist, Pedorthist, High risk foot clinicians, endochronologist or orthopedic/podiatric surgeon).
Non-weight bearing: Using crutches, a walker, or a wheelchair to keep weight off the foot.
Total Contact Cast (TCC): Custom cast to protect the foot and allow healing.
Wound Care Management: Antibiotic treatment is indicated in all infected wounds. Hospitilisation, immobilisation, and IV antibiotics are indicated for limb threatening or uncontrolled infections.
Later stages/long term treatment may require: Custom orthotics or footwear or Surgical reconstruction (in severe deformity).
If your or someone you know would like more information, feel free to reach out to our clinic for more information.
References:
https://www.ncbi.nlm.nih.gov/books/NBK470164/
https://www.physio-pedia.com/Charcot_Foot- 4 stages
https://www.racgp.org.au/afp/2013/january-february/bilateral-diabetic-charcot-foot
https://pmc.ncbi.nlm.nih.gov/articles/PMC3161273/
https://www.england.nhs.uk/north-east-yorkshire/wp-content/uploads/sites/49/2019/07/the-charcot-foot.pdf
https://www.aafp.org/pubs/afp/issues/2018/0501/p594.html
