Role of metaphyseal cancellous bone defect size in secondary displacement in Colles' fracture

The purpose of this study was to evaluate the role of the metaphyseal cance llous bone defect size in secondary dislocation of Colles' fracture. Thirty -five patients with a dislocated Colles' fracture were examined by computed tomography (CT) for metaphyseal bone defects. The size of the defect was a ssessed and related to the surface area of the cross-section of the distal radius at the site of the defect. The relative size of the defect correlate d with the severity of dorsal angulation of the fracture but not with the s hortening of the radius seen after cast immobilization. We concluded that s econdary displacement of the distal radius is partly mediated through the m etaphyseal cancellous bone defect, and to prevent malunion in dorsal angula tion, operative treatment or possibly filling of the defect should be consi dered even as early as during primary reduction if a large defect is suspec ted.