Nonunion in a displaced fracture of the scaphoid is four times more likely than nonunion in an undisplaced fracture of the scaphoid if treated in a plaster cast, according to the results of this study.
According to the study abstract, the researchers searched electronic databases for scaphoid fractures either treated in a plaster cast or fixed operatively. For the purposes of the study, displacement was defined as a gap or step larger than 1 mm. Outcomes between displaced and undisplaced scaphoid waist fractures treated in a plaster cast were compared within the nonoperative group, and the researchers determined the odds ratio of nonunion when comparing plaster cast treatment to operative treatment.
The authors reported a total of 1,401 scaphoid fractures from 7 studies — 93% of which were treated with a plaster cast. Of these fractures, 207 (15%) exhibited displacement. According to the abstract, nonunion was found in 18% (37 of 207) of displaced scaphoid fractures treated with a plaster cast.
“The pooled relative risk of fracture nonunion was 4.4,” the authors wrote. “In the surgical group, we identified six observational studies in which 157 ‘displaced’ fractures of the scaphoid were surgically fixed. Only two of these fractures did not heal.”