Charcot

Question 1

what is charcot arthropathy?

Answer 1

a chronic progressive neuroarthropathy because of loss of protective sensation

Question 2

what is the pathophysiology of charcot?

Answer 2

Pathophysiology
1. Abnormal sensation:
Congenital
* hereditary motor and sensory neuropathy
Acquired
* diabetes 90% cases - 1% of diabetic patients with diabetes for >12yrs
* alcoholic peripheral neuropathy
* spina bifida
* syphillus
* post traumatic
* peripheral neuropathy
2. loss of normal architecture
- incongruity
- deformity
3. subluxation and dislocation

Theories for why it happens:
NEUROVASCULAR
- bone destruction and ligamentous weakness
- secondary to unregulated hyperaemia due to autonomic dysfunction
- Increases blood flow via av shunting causing increased bone resorption via RANK/RANKL pathway
- weakness due to inflammatory cascade

NEUROTRAUMATIC
- multiple episodes of microtrauma in insensate joints without adequate protection leading to joint destruction

Question 3

stages of charcot - Eichenholtz

Answer 3

Eichenholtz
* prefragmentation
* fragmentation
* coalescence
* consolidation

Prefragmentation
- joint oedema
- normal radiographs
- positive bone scan

Fragmentation
- painful swollen foot - looks like infection
- osseous fragmentation and dislocation

Coalescence
- deformity settles
- less swollen
- coalescence of fragments and resorption of fine debris

consolidation
- no joint oedema
- settled foot
- consolidation and remodelling of fractures
- time for deformities to settle:
- forefoot - 6months
- midfoot - 12months
- hindfoot - 18months

Question 4

Assessment and management of charcot

Answer 4

presentation
Acute
- mimics infection
- 50% painful and 50% painless

Chronic
- deformity
- arch collapse
- rockerbottom foot
- instability

Assessment
- identify at risk - 10g semmes-weinstein monofilament - protective sensation if can feel filiament buckle
- loss of vibration sense - tuning fork - early sign

Management goals
- reduce deformity
- prevent ulceration

Principles of management
- supportive
- CROW - charcot restraint orthotic walker - consolidation

**Acute management **
- good diabetic control and education
- accomodative footwear - maintain shape of foot and prevent deformity
- aggressive treatment of ulcers - closed contact casting - non-WB 2-4months then protective WB 6 months - 2yrs
- total contact cast - increases contact area = decreases contact pressure = allows ulcers to heal
- only operate if dislocations - fusion instead of fixation

**Chronic management **
- wait for consolidation phase
- orthotics and braces
- fusion

Acute surgery
APEX MEDIAL DEFORMITY
- medial dislocation of navicular and cuneiform with forefoot in abduction - skin necrosis risk
- needs an ostectomy

APEX LATERAL DEFORMITY
- dorsal dislocation of navicular and cuneiform
- medial column shortening
- lateral rockerbottom deformity
- needs a fusion

Surgery in diabetic foot
- ostectomy - offload the ulcer to left the heal
- hindfoot fusion - nail - tibiotalarcalc
- amputation - recurrent/ untreatable deformity