SUMMARY
Diabetic Charcot Neuroarthropathy is a chronic, progressive, and destructive condition resulting from loss of protective sensation, leading to collapse and deformity of the foot and ankle joints.
Clinically, it presents with a warm, swollen, erythematous foot, often mistaken for infection; however, erythema characteristically decreases with elevation.
Radiographs demonstrate joint space obliteration, osseous fragmentation, and joint subluxation or dislocation.
Initial management consists of strict immobilization with total contact casting in acute stages. Surgical intervention is reserved for severe, unstable, or non-braceable deformities.
EPIDEMIOLOGY
Incidence
• 0.1–1.4% of patients with diabetes
• Up to 7.5% of patients with diabetes and established neuropathy
Demographics
• Type 1 diabetes: typically presents in the 5th decade (20–25 years after diagnosis)
• Type 2 diabetes: typically presents in the 6th decade (5–10 years after diagnosis)
Anatomic Distribution
• Foot and ankle (most common)
• Bilateral involvement in 9–35%
• Less commonly: knee, shoulder, elbow
ETIOLOGY AND PATHOPHYSIOLOGY
Peripheral Diabetic Neuropathy
• Sensory neuropathy → loss of protective sensation
• Motor neuropathy → muscle imbalance and progressive deformity
• Autonomic neuropathy → increased local blood flow and bone resorption
Pathophysiologic Theories
Neurotraumatic theory
• Insensate joints subjected to repetitive microtrauma
• Inability to mount protective responses
Neurovascular theory
• Autonomic dysfunction → arteriovenous shunting
• Increased bone turnover and weakening
Molecular Mechanisms
• Elevated inflammatory cytokines (IL-1, TNF-α)
• Activation of NF-κB
• Dysregulation of RANK / RANKL / OPG pathway → osteolysis
CLASSIFICATION
Brodsky Classification (Anatomic)
• Type 1: Tarsometatarsal & naviculocuneiform joints (60%)
– Midfoot collapse → rocker-bottom deformity
• Type 2: Subtalar, talonavicular, calcaneocuboid joints (10%)
– Highly unstable, prolonged immobilization required
• Type 3A: Tibiotalar joint (20%)
– Progressive varus or valgus deformity
• Type 3B: Calcaneal tuberosity fracture (<10%)
• Type 4: Combined regions (<10%)
• Type 5: Forefoot only (<10%)
Eichenholtz Classification (Temporal)
• Stage 0 (Prefragmentation):
– Clinical swelling and warmth, radiographs normal
• Stage 1 (Fragmentation):
– Osseous fragmentation, joint dislocation
• Stage 2 (Coalescence):
– Decreased edema, fragment resorption
• Stage 3 (Reconstruction):
– Consolidation and remodeling
PRESENTATION
Symptoms
• Swelling and warmth
• Pain present in ~50%, painless in others
• Functional instability
Physical Examination
Acute Charcot
• Diffuse swelling
• Temperature difference ≥3°C compared to contralateral side
• Erythema that decreases with elevation
Chronic Charcot
• Structural deformity
• Bony prominences
• Rocker-bottom foot
• Ligamentous instability
Neurologic Exam
• Semmes-Weinstein 5.07 monofilament
• Sensitivity: 40–95%
IMAGING
Radiographs
• Weight-bearing AP and lateral foot views
• Ankle series
Findings
• Early: degenerative changes mimicking osteoarthritis
• Late:
Joint space obliteration
Osseous fragmentation
Subluxation or dislocation
Heterotopic ossification
MRI
• Helpful for soft tissue evaluation
• Limited specificity in distinguishing Charcot from infection
TREATMENT
Nonoperative (First-Line)
• Total Contact Casting
Immobilization with strict non–weight bearing
Cast changes every 2–4 weeks
Duration: 2–4 months
• Transition Bracing
Charcot Restraint Orthotic Walker (CROW)
• Footwear Modifications
Double rocker sole in Eichenholtz stage 3
• Medical Management
Bisphosphonates
Neuropathic pain agents
Success rate: ~75%
Operative
Indications
• Non-braceable deformity
• Recurrent instability
• Severe structural collapse
Procedures
• Exostectomy ± TAL for focal deformities
• Deformity correction with arthrodesis
• External fixation when bone quality is poor
Outcomes
• Complication rates up to 70%
• High risk of infection, nonunion, and hardware failure
PROGNOSIS
Depends on:
• Stage at diagnosis
• Degree of deformity
• Patient compliance with immobilization
• Neuropathy severity