Neuropathic Arthropathy (Charcot Joint)

Progressive degeneration and destruction of a joint due to loss of sensory innervation (proprioception and pain). This leads to repeated trauma and joint damage without the patient noticing pain.

Causes

• Diabetes mellitus (most common cause in the US; affects feet and ankles)
• Syphilis (tabes dorsalis) – historically common cause; affects knees, hips, and ankles
• Peripheral neuropathy from other causes:
  • Leprosy
  • Spinal cord injury
  • Syringomyelia (especially affects upper extremity joints like shoulder/elbow)
  • Alcoholic neuropathy
  • Vitamin B12 deficiency

Clinical Features

• Swollen, warm, erythematous joint mimics infection or gout
• Usually painless or minimally painful despite severe joint destruction
• Joint instability, deformity, and decreased range of motion
• History of neuropathy or sensory loss
• Commonly affects weight-bearing joints (ankle, foot, knee)

Diagnosis

• X-ray findings:
  • Joint destruction and fragmentation
  • Bone resorption
  • Dislocation or subluxation
  • New bone formation (“licked candy stick” appearance)
  • Joint debris
• Labs to rule out infection (normal or mild inflammatory markers)

Management

• Offloading/immobilization of affected joint (e.g., total contact casting)
• Treat underlying cause of neuropathy
• Surgical intervention for severe deformity or instability (rare)
• Patient education to prevent trauma