arthrodesis

Definition

Spontaneous osteonecrosis of the navicular

Non-Operative

Education regarding shoe wear

- extra wide / large toe box

Insoles

- longitudinal arch support

- pre MT dome for metatarsalgia

- podiatry to attend to callosities

Toe spacers

Analgesia

Operative

Indications

1.  Continued pain and discomfort

2.  Difficulties with shoe wear

Results 

90% fusion rates

Lose70% sagittal plane ROM

Disadvantages of Arthrodesis 

Non union rates up to 12%

Decreased gait speed

Poor mobility over uneven surfaces

Issues

1.  Painful Bunion / Hallux valgus

2.  Metatarsalgia / MTPJ dislocation

3.  Claw toes

Biomechanics

Able to achieve relatively high level of function after STJ fusion

- previously believed that isolated STJ fusion should not be performed

- believed that triple arthrodesis was operation of choice for hindfoot

- STJ fusion has superior result with less stress on AJ

Average loss of DF 30% / PF 10%

Position of hindfoot determines flexibility of transverse tarsal (CCJ & TNJ) joints

- imperative that fusion be positioned in ~ 5^o valgus 

Nalebuff Classification

Type I - Boutonniere 

- commonest

- MP flexion /  IP hyperextension

- usually EPB rupture with EPL subluxation

Type II

- Boutonniere & Swan Neck

- doesn't exist according to Nalebuff

Conditions

1.  PIPJ Synovitis

- synovectomy via dorsomedial approach

2.  Flexor tenosynovitis

- may cause trigger finger

- trial HCLA

- remove synovits but don't release A1 pulley

- will worsen ulna drift

3.  DIPJ

- rarely affects

Indications

Indications have narrowed

- due to success of shoulder arthroplasty

1. Chronic infections of GHJ

2. Stabilization in paralytic disorders

3. Post-traumatic brachial plexus palsy

4. Salvage of failed GHJ Arthroplasty

- may need bone graft procedures

5. Arthritic diseases unsuitable for arthroplasty / young patient