The fractured carpal scaphoid. Natural history and factors influencing outcome.

The scaphoid fracture is commonest in young men in the age group 15 to 29 years, who have the highest incidence of non-union, take the longest time to unite, lose more time from work, and spend the longest time as outpatients. A union rate of 95 per cent can be achieved using standard simple treatment. All but a few fractures are visible on the first radiograph, and failure of visualisation at this stage is not associated with a bad outcome. The postero-anterior and semipronated views are the most important to scrutinise. Crank-handle injuries have a particularly bad prognosis when they produce a transverse fracture of the waist of the scaphoid. Poor prognostic factors are displacement during treatment, the fracture line becoming increasingly more obvious, and the presence of early cystic change. The severity of trauma is an important factor to elicit from the history.