Causes / typical injury mechanism:
- Charcot neuropathy is acute or repetitive trauma to the joint secondary to loss of sensation, most often due to diabetic peripheral neuropathy.
- Repetitive trauma leads to fractures and joint destruction whose healing results in bone deformations.
- Swollen, erythematous joint that is warmer (3-5 °C higher) than unaffected joints.
- Pain may be present but is less than is to be expected in a sensate foot.
- Advanced Charcot neuropathy will present with bone deformity as well as significant modification to the arch of the foot.
- There is a higher prevalence in males aged 50-60 years.
- Prevalence among individuals with diabetes ranges from 0.1%-0.4%. Most people who develop diabetic Charcot neuropathy have had diabetes for at least 10 years.
- Prevalence among people who also exhibit peripheral neuropathy is 35%.
- Diabetes (higher risk for those diagnosed for at least 10 years and for patients with type 1 diabetes)
- Peripheral neuropathy
- Neurotraumatic – Acute or repetitive trauma to the joint secondary to loss of protective sensation due to diabetic peripheral neuropathy. Repetitive trauma leads to fractures and joint destruction whose healing results in bone deformations. Bone and joint deformations result in ulceration and lesions on the foot and ankle.
- Neuro-bone-inflammatory – The role of the inflammatory response in individuals with Charcot neuropathy likely plays a role in the degeneration of the weight-bearing joint.
- Neurovascular – Alterations in the sympathetic nervous system results in increased blood flow to the extremities and arteriovenous shunting. This altered blood flow contributes to bone resorption and ultimately results in bone fractures.
- Stage 0 – Mild inflammation, soft tissue edema, normal x-ray, abnormal MRI (with signs of microfracture, edema of bone marrow, contusion)
- Stage 1 – Severe inflammation, soft tissue edema, abnormal x-rays indicating microfracture, abnormal MRI (with signs of microfracture, edema of bone marrow, bone resorption with articular dislocation)
- Stage 2 – Signs of coalescence, remodeling, and healing of fractures
- Stage 3 – Bone remodeling, ulceration, bone deformity
- Acute – Erythema, elevated foot temperature, progressive bone deformity
- Chronic – Subluxation, deformity, rocker-bottom foot deformity, ankle varus or valgus
