Charcot Foot

Symptoms

• While peripheral neuropathy develops over decades, the progression of Charcot foot (ligament tears, small fractures, subluxation, dislocation, deformity) can occur in a matter of weeks or months. A minor trauma, such as twisting the foot, can initiate the process. Increased bone resorption makes the joints in the foot susceptible to small fractures.
  
  Because of the loss of pain perception and the loss of the sense of position of the foot, joints receive repeated injuries, such as torn ligaments and bone fractures.
  
  Early signs that may present soon after injury include the following:
• Heat
• Insensitivity in the foot
• Redness
• Strong pulse
• Swelling of the foot and ankle
• The early stage of Charcot foot may manifest these symptoms:
• Dislocation of the joint
• Instability of the joint
• Subluxation (misalignment of the bones that form a joint)
• Swelling
• After an injury, the synovial fluid that leaks out of the joint capsule may produce swelling.
• Muscle weakness and slack ligaments caused by nerve damage cause instability of the joint and subsequent misalignment (called subluxation) and/or dislocation.
• Subluxation initiates the process of degenerative joint disease (arthropathy). The ends of misaligned bones grind against each other and fragments of bone and cartilage fall into the joint and often produce audible crepitus, a coarse grating sound, when the joint is moved. The physician may be able to feel these fragments in the joint.
  
  Deformity of the foot that occurs in advanced disease is caused not only by joint displacement and/or dislocation but also by osteophytes and fractures. Large bony overgrowths, or osteophytes, develop as the body replaces lost bone with new bone and may protrude from the top of the foot. Fractures may cause the tarsal bones to collapse and outward bowing of the arch, or "rocker foot."
  
  Complications
  
  Calluses and ulcers may form when bony protrusions rub inside the shoes. Infected pressure ulcers and osteomyelitis (inflammation of the bone caused by infection) may develop. Septic arthritis may manifest with malaise and fever. Characteristics of septic arthritis include inflammation of synovial membranes and infected synovial fluid escaping from the joint capsule into the joint. Compression of blood vessels and nerves are caused by disorganization of the joint and may not produce symptoms due to loss of feeling in the foot.