Avascular Necrosis of the Scaphoid       

- See:
    - Scaphoid Reconstruction for Nonunion
    - Vascular Anatomy of Scaphoid:

- Discussion:
    - may be associated w/ longstanding nonunion of proximal pole fractures, especially when associated w/ previous surgery;
    - AVN of scaphoid is often difficult to diagnose radiographically and therefore it is usually necessary to assess vascularity of the 
           proximal pole at the time of surgery;
           - absence of punctate bleeding in the proximal fragment (after debridement) is the best indicator of AVN;
           - following debridement, punctate bleeding should be present from the surface of the scaphoid while the tourniquet remains elevated;

- Radiographic Findings:
    - plain radiographs tend to underestimate the presence of AVN (as compared to intraoperative bleeding or MRI);
    - proximal fragment may have:
          - ground-glass appearance or increased bone density;
          - loss of trabecular pattern;
          - cystic changes;
          - subchondral collapse and fragmentation;
    - radiographic classification:
          - stage 0: none;
          - stage 1: patchy areas of radiodensity of proximal pole;
          - stage 2: involvement of entire proximal pole;
          - stage 3: AVN w/ carpal collapse;

- MRI:
    - evolving role;

- Treatment:
    - Four Corner Fusion:

Avascular necrosis after scaphoid fracture: a correlation of magnetic resonance imaging and histology.

Late treatment of a dorsal transscaphoid, transtriquetral perilunate wrist dislocation with avascular changes of the lunate.

Surgical Treatment of Nonunion and Avascular Necrosis of the Proximal Part of the Scaphoid in Adolescents

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, April 12, 2012 3:13 pm