Definition
Neuropathic arthropathy
- progressive destructive arthropathy 2° to neurological condition
- usually minimal to no trauma
Etiology
Diabetes
Leprosy / syphilis
Other - polio / paraplegia / syringomyelia
Pathophysiology
1. Neuro-traumatic theory - cumulative trauma in insensate foot
2. Neurovascular theory
- neurally stimulated vascular reflex stimulates bone resorption
Natural history
Eichenholtz Classification
| Stage 0 | Stage 1 Dissolution | Stage 2 Coalescence | Stage 3 Reconstruction | |
|---|---|---|---|---|
| Findings |
Acute inflammation - swollen, red, warm - reduces with elevation |
Acute inflammation - swollen, red, warm - reduces with elevation |
Inflammation decreases Reduced swelling Reduced temperature
|
Normal temperature Swelling reduced |
| Xray | Normal |
Demineralisation of regional bone Periarticular fragmentation Joint dislocation |
Absorption of osseous debris Organization and early healing of fracture fragments Periosteal new bone formation |
Smoothing of edges Oosseous or fibrous ankylosis Bone healing Resolution of osteopenia
|
| Management |
NWB May prevent collapse |
Total contact cast until stage 2 FWB |
CROW (Charcot Resistant Orthotic Walker) Bivalved AFO |
Accommodative shoes with custom moulded orthotic
CROW or AFO if ongoing ankle instability |
|
|
Midfoot dissolution, coalescence and reconstruction
Brodsky Classification
| Type 1 Midfoot (60%) | Type 2 - Hindfoot (30%) | Type 3 (10%) |
|---|---|---|
|
Metatarsocuneiform and naviculocuneiform
Collapse of the medial longitudinal arch with rocker bottom foot |
Subtalar joint, talonavicular, calcaneocuboid
More unstable than type 1 Require longer periods immobilisation |
3a: Tibiotalar joint - most unstable pattern
3b: Fracture calcaneal tubercle - weak push-off and ulceration |
Examination
Stage 0 / Stage 1
Foot very red
- ? cellulitis
- elevate for 10 minutes and the redness reduces
Reduction of redness with elevation
Xray
Midfoot collapse
Midfoot collapse and rocker bottom foot with small ulcer
Midfoot collapse with subluxation of midtarsal joints
Hindfoot collapse with ulcer
Nonoperative Management
Goal
Stable plantigrade foot that is shoe-able or braceable
Avoid ulcers
Indications
Eichenholtz Grade 0 / 1 - Total contact cast (TCC)
www.boneschool.com/total-contact-cast
Eichenholtz Grade 2 / 3 - CROW (Charcot Resistant Orthotic Walker)
Operative Management
Indications
1. Severe deformity unable to brace or wear shoes
2. Skin at risk
3. Ulcers - type 1 / midfoot collapse
4. Marked instability - type II / hindfoot
Contra-Indications
Uncontrolled diabetes
Peripheral vascular disease
Medically unwell
Stage 1 disease
Goals
Restore alignment & stability
- allow brace and / or shoe wear
- protect skin
- prevent amputation
Timing
Stage III - resolution / consolidation
Midfoot surgery
Background
Midfoot most common site for neuropathic destruction
- mid foot collapse
- rocker bottom foot
- recurrent ulceration
Options
Ostectomy
Reconstruction
Midfoot Ostectomy
Remove bony prominence causing ulcer
- avoid areas of ulceration
- medial or lateral incision
- full thickness soft tissue dissection to expose exostosis
- remove with osteotome / saw and smooth edges with rasp
- postoperative TCC for 6 weeks
Midfoot Reconstruction
Hindfoot surgery
Background
Hindfoot Charcot not amenable to bracing
- arthrodesis v amputation
- frequently bilateral
- try to avoid bilateral amputations
Hindfoot arthrodesis
Contraindications
- Stage I
- active infection
- uncontrolled diabetes
- end stage peripheral vascular disease
- poor bone stock
- non compliance
Technique
Full thickness skin flaps
- resect bone / correct deformity
- long hindfoot nail - risk of tibial stress fractures
- non weight bear in TCC for 3 months
- lifelong AFO
Results