Charcot’s Foot

• a neuroarthropathic process with osteoporosis, fracture, acute inflammation and disorganisation of foot architecture. 
• During the acute phase, Charcot’s foot can be difficult to distinguish from infection.
• SSx: red, swollen oedematous and possibly painful foot in the absence of infection. 
• It is associated with increased bone blood flow, osteopenia and fracture or dislocation

• Charcot arthropathy is a condition of the foot and ankle caused by an inability to sense injuries, which can result in significant deformities. 
• Neuropathy (nerve damage) MUST be present for Charcot foot to develop, and the most common cause of that neuropathy is diabetes.
  • Diabetic patients with neuropathy can sustain fractures or dislocations in the foot without realizing it. 

• These injuries can:
  • Occur from obvious traumatic events, such as falls or ankle sprains.
  • Develop slowly over time as a result of altered weight distribution on a diabetic foot (microtrauma). 
  • In a normal patient, these atypical forces would generate pain, causing the patient to automatically adjust their stance and redistribute weight before any injury or damage occurs in the foot. 
  • A diabetic, however, will not sense pain or adjust their weight, so these forces can cause fractures and other injuries over time.
  • Without normal pain sensation, a diabetic may continue to walk on an injured foot, worsening the injury and leading to significant deformity. 
  • Only about 25 to 50% of patients with Charcot foot report a specific injury that they can recall

• other risk factors that can contribute to Charcot:
  • obesity 
  • alcoholism
  • leprosy
  • myelomeningocele
  • tabes dorsalis/syphilis
  • syringomyelia

• The resulting deformities in Charcot foot can lead to several problems:
  • They can make normal shoe wear difficult or even impossible.
  • They can be significant enough to make the foot and ankle unstable and thus unable to support normal walking.
  • The ultimate problem in Charcot, however, is that the deformities can create areas of prominent bone under the skin (the bone is immediately below the skin surface). 
  • This leads to ulcers, or wounds that are caused by excess pressure on the skin. Once the skin breaks, the risk of developing an infection in the foot is very high, and due to poor blood flow, diabetics have a difficult time both healing wounds and fighting infections. 
  • For this reason, diabetics with Charcot foot have a 50% chance of ending up with an amputation if they develop an ulcer, as opposed to only a 10% chance without an ulcer.

Management

• Nonoperative
  • total contact casting, shoewear modifications, medications
    • casts changed every 2-4 weeks for 2-4 months
  • orthotics
    • Charcot restraint orthotic walker (CROW) boot can be used after contact casting     
  • shoe modifications
  • medications
    • bisphosphonates
    • neuropathic pain medications
    • antidepressants
    • topical anesthetics
  • outcomes
    • 75% success rate

• Operative
  • resection of bony prominences (exostectomy) and TAL  
  • deformity correction, arthrodesis +/- osteotomies     
  • amputations
    • indications
      • failed previous surgery (unstable arthrodesis)
      • recurrent infection