Avascular Necrosis

Diagnosis

 

Xray

- sclerosis

 

Scaphoid Fracture Proximal Pole AVNScaphoid Proximal Pole ORIF AVN

 

CT

 

Scaphoid AVN CT

 

MRI

- probably the most sensitive and specific

 

Bone Graft v Vascularised bone graft

 

Merrell J Hand Surg Am 2002

- meta-analysis

 

1.  Bone graft with proximal pole AVN

- union 50%

 

2.  Vascularised bone graft with proximal pole AVN

- union 88%

 

Vascularised bone grafting / VBG

 

1.  Pronator quadratus pedicle graft

- much less common now

 

2.  Vascularised distal radius graft / Zaidemberg

- most common

 

3.  2nd metacarpal graft

- very common

 

Technique Zaidemberg

 

Dorso-radial approach

- 1/2 intercompartmental supraretinacular branch of the radial artery

- travels distal to proximal

- between tendons of the first and second extensor compartments

- can use 2/3 if 1/2 small or missing

- follow to distal radius

- osteotome 3 sides preserving pedicle

 

Dorsal approach to scaphoid

- open non union site

- insert VBG

- fixation with screw