Closed cast treatment of scaphoid fractures.

Cast immobilization of the wrist remains the treatment of choice for stable fractures of the waist and distal pole of the scaphoid. Criteria for diagnosis of stability should be stringent; plain radiographs may be misleading. CT may provide more accurate information on displacement. Immobilization of the thumb confers no advantage and restricts function unnecessarily. Evidence to support immobilization of the elbow is weak, but it may be useful for selected fractures. A cast does not protect the carpus from the effects of axial loading, which can produce large angulatory forces at the fracture. A gap or fracture offset of 1 mm or more are indicators of instability with potential for nonunion or malunion; internal fixation should be considered for these fractures. Internal fixation may also be considered routinely for proximal pole fractures, regardless of the degree of displacement, in view of their long healing time and high risk of nonunion after cast treatment.