Charcot Joint

Charcot Foot AP Charcot Foot Lateral

 

Definition

 

Neuropathic Arthropathy

 

Progressive destructive arthropathy 2° to neurological condition

- usually minimal to no trauma

 

Aetiology

 

DM

- western world

 

Leprosy / syphilis

- third world

 

Other

- polio

- paraplegia

- syringomyelia

 

Pathophysiology

 

Likely combination of :

 

1.  Neuro-traumatic theory

- cumulative trauma in insensate foot unrecognised

- results in progressive joint destruction

 

2.  Neurovascular theory

- neurally stimulated vascular reflex

- stimulates bone resorption

 

Newer theory: due to inflammatory cytokines

(TNF Alpha & IL-1) = stimulates osteoclast resorption  

 

Classification Temporal - Eichenholtz

 

Sidney N Eichenholtz, American surgeon, 1966

 

Stage 0

 

- added by Shibata et al 1990

- clinical signs (swelling/ erythema) precede XRay changes

- NWB during this period may prevent XRay changes

 

Stage 1 Dissolution

 

Findings

- acute inflammation (swollen, red, warm)

- DDx infection

- erythema reduces with elevation 10 minutes

 

Charcot FootCharcot Foot Elevated

 

X-ray

- demineralisation of regional bone

- periarticular fragmentation

- joint dislocation

- hyperaemia precedes fragmentation by hours to weeks

 

Charcot Foot Stage 1 Fragmentation

  

Treatment

- TCC remains gold standard

- WBAT ; no evidence that better outcomes with NWB

- applied weekly until clinical progression to stage II

- frequency of application may decrease as progress

 

Stage 2 Coalescence

 

Findings

- inflammation decreases / less swelling

- reduced temperature

 

X-ray

- absorption of osseous debris

- organization and early healing of fracture fragments

- periosteal new bone formation

 

Charcot Foot Stage 2 Resolution

 

Treatment

- TCC or transition to CROW (Charcot Resistant Orthotic Walker)i.e bivalved AFO

- may need to modify CROW a number of times before stage III

 

CROW

 

Stage 3 Reconstruction

 

Findings

- normal temperature

- swelling reduced

- clinically stable

 

X-ray

- smoothing of edges

- sclerosis, osseous or fibrous ankylosis

- complete bone healing 

- resolution of osteopenia

 

Charcot Foot Stage 3 Consolidation

 

Treatment

- accommodative shoes with custom moulded orthotic

- CROW or AFO if ongoing ankle instability

 

Px

- 30% will relapse between stages

- 7% risk of BKA without ulcer

- 28% risk of BKA with ulceration

 

Classification Anatomical - Brodsky

 

James Brodsky; Orthopaedic F&A Surgeon; Dallas Tx ; 1993

 

Type 1 Midfoot (60%)

- metatarsocuneiform and naviculocuneiform

- collapse of the medial longitudinal arch with rocker bottom foot

- progress through Eichenholtz stages quicker

- may present stage III with bony prominences & DFU

 

Charcot Midfoot

 

Type 2 - Hindfoot (30%)

- any / all subtalar joint i.e TNJ; subtalar; calcaneocuboid

- more instability than type 1

- require longer periods immobilisation

- varus or valgus

 

Charcot Hindfoot

 

Type 3 (10%) 

3a

- tibiotalar joint

- usually post ankle fracture

- most unstable pattern

 

3b

- pathologic fracture calcaneal tubercle

- weak push-off and ulceration

 

Investigation

 

DDx infection

- MRI

- combination labelled WCC + Bone Scan if MRI CI

 

Management

 

Goal 

 

Stable plantigrade foot that is shoe-able or braceable

 

Few require operative surgery

- control with casts and braces

 

Indications For Surgery 

 

1.  Severe deformity unable to brace

 

2.  Marked instability (usually type II or IIIa)

 

3.  Ulcers

- common type 1

- aim to try and heal ulcer first

- may be caused by fixed bony deformity i.e. midfoot collapse

 

4.  Soft tissues at risk

 

Contra-Indications

 

Uncontrolled diabetes

PVD

Medically unwell

Stage 1 disease

 

Goals of Operative Management

 

Restore alignment & stability so brace &/or shoe can be worn

- prevent alternative which is amputation

 

Timing of Surgery

 

Operating in stage 1 or 2 remains very controversial

 

Correct deformity in resolution / consolidation stage III 

- after cast / brace, shoe failed

 

Acute Fractures

 

Issue

- is it charcot or non charcot?

 

1.  Likely Charcot

 

Patient

- fracture a week or 2 old / red & swollen

- peripheral neuropathy & displaced fracture

- mimimal trauma

 

Eichenholtz I

- treat non-operatively

 

2.  Non Charcot 

 

Truly acute fracture

- reasonable trauma

- patient has peripheral neuropathy / DM

- treat as per usual, but accept higher complication rate

 

Management

- ORIF early before acute (dissolution) phase sets in

- if delayed be wary of ORIF as bone stock very poor

- need very strong and augmented ORIF

- must warn of risk of Charcot in acute fracture

- with peripheral neuropathy double period of immobilisation

- NWB 3/12 then further 3-4 month in TCC

 

Surgical procedures

 

1.  Midfoot ostectomy

 

Charcot Midfoot CollapseNeuropathic Ulcers from midfoot collapse

 

Midfoot most common site for neuropathic destruction

- mid foot collapse 

- apex of rocker-bottom common site for recurrent ulceration

 

Technique Ostectomy

 

1.  Attempt to heal ulcer first

- TCC

- debridement +/- IV ABs if OM

 

2.  Remove bony prominence causing ulcer

- medial or lateral incision

- avoid areas of ulceration

- full thickness soft tissue dissection to expose exostosis

- remove with osteotome / saw

- smooth edges with rasp

- haemostasis

- closure over drain; compressive dressing

- postoperative TCC for 6/52

 

2.  Hindfoot Realignment & Arthrodesis

 

Indications

- hindfoot Charcot not amenable to bracing 

- severe deformity or instability following failed bracing

- amputation is only alternative

 

Amputation v Arthrodesis

 

May develop bilateral issues

- try to avoid bilateral amputations

 

Contraindications to Arthrodesis

1. Disease Factors

 - Active infection (consider staged)

 - Stage I Eichenholtz

 - Insufficient soft tissue coverage

 - Insufficient bone stock

2. Patient Factors

 - Uncontrolled DM or malnutrition

 - Nonreconstructable PVD 

 - Non-compliant  

 

Technique

 

Preoperative

- cast / TCC till Stage III

- optimise HBA1c and nutrition

 

Intraoperative

- longitudinal incisions with full thickness flaps under no tension

- meticulous soft tissue handling

- resect bone to correct deformity

- strongest fixation device possible ; often augmented

- if using hindfoot nail ensure >200mm length

(risk of tibial stress fractures with shorter nail)

- often need percutaneous T Achilles lengthening

- alternative: fine wire fixation if active infection

 

Postoperative

- TCC - 3/12 NWB ; 1/12 PWB; 1/12 WBAT

- Lifelong AFO

- Periodic 6/12 follow-up

 

Results

- Lowery FAI 2012 - 76% bony fusion; 22% fibrous ; 1.2% amputation

- fibrous union can still result in good function