Union rates after proximal scaphoid fractures; meta-analyses and review of available evidence.

We carried out a comprehensive analysis of publications to investigate long term union rates of acute proximal scaphoid fractures. Of 1147 acute scaphoid fractures managed nonoperatively that were available for analysis, 67 (5.8%) were proximal. Amalgamating publications revealed that 34% of acute proximal scaphoid fractures progress to nonunion when managed nonoperatively. A meta-analysis showed that the relative risk of nonunion for these fractures is 7.5 compared with more distal fractures, also managed nonoperatively. More trials are needed to allow direct comparison of acute proximal scaphoid fractures managed operatively and nonoperatively. Power calculations indicate that 76 cases will need to be recruited for such a study. Currently, the proximal scaphoid is defined inconsistently. To avoid misclassification we suggest the region is defined as the proximal fifth of the bone, and computer tomography is used during follow-up.