Non union

Scaphoid Non union xrayScaphoid Nonunion Xray 2

 

NHx

 

Convincing association with development of osteoarthritis

- arthritic changes beginning at radial styloid

- progress to scaphocapitate & capitolunate 

 

End point representing scaphoid nonunion advanced collapse wrist (SNAC)

 

Issues

 

AVN

Humpback deformity (must correct to improve kinematics)

SNAC (contraindication to surgery to achieve union)

 

Xray

 

Sclerotic margins / no sign of healing

 

Scaphoid Nonunion Sclerotic Margin

 

Humpback deformity

 

Scaphoid Humpback Deformity

 

Look for signs of AVN

 

Scaphoid Non union

 

MRI

 

Advantage

- exclude AVN

- AVN has low signal on T1 and T2

- if AVN use vascularised bone graft

 

CT

 

Identify humpback deformity / plan size and shape of bone graft

 

Scaphoid Humpback CT 1Scaphoid Humpback CT 2Scaphoid Nonunion Humpback Deformity CT

 

Options

 

1.  Russe-type inlay corticocancellous bone graft 

- volar approach

- 2 corticocancellous struts 

- cancellous surfaces facing each other 

- placed longitudinally inside scaphoid

- 85% to 95% union

 

2.  Fisk wedge graft

- trapezoidal / triangular iliac crest graft

- designed to restore the scaphoid alignment 

- correct humpback deformity

- union rates of 95 - 100% with fixation

 

Scaphoid NonunionScaphoid Nonunion LateralScaphoid Nonunion Iliac Crest Bone GraftScaphoid Nonunion Iliac crest Bone Graft

 

Waist Non union

 

Technique

 

Volar approach

- clean fracture site of fibrous tissue

- osteotomes to reduce deformity

- do not disrupt dorsal cortex

- burrs if needed to remove fibrotic tissue

 

Scaphoid Approach

 

Assess for AVN

- look for evidence of punctate bleeding from distal fragment

 

Place bone graft

- reduce deformity if necessary

- fix with K wire

- place cannulated screw

 

Scaphoid Bone GraftScaphoid BG ORIF 1Scaphoid BG ORIF 2

 

Results

 

90% union

- some loss of ROM and strength 

 

Proximal pole non union

 

Scaphoid Proximal Pole Non UnionScaphoid Proximal Pole Nonunion Bone GraftScaphoid Proximal Pole Nonunion Bone Graft 2

 

Dorsal approach

 

Lower union rates

- 67%

- ? role for vacularised bone graft