Remodelling after distal forearm fractures in children. III. Correction of residual angulation in fractures of the radius.

The outcome of residual angulation of the radius after 38 distal forearm fractures in children was investigated. The period of observation ranged from 4 months to 10 years and 8 months. The correction of a residual angulation after a fracture was shown to be governed by three factors. 1. An increase in the time between healing of the fracture and completed growth at the epiphyseal plates resulted in a more complete correction. 2. A larger adaxial dislocation of the epiphyseal plate at the time of healing of the fracture, reflecting a larger primary fracture angulation and a greater distance from the fracture to the epiphyseal plate, resulted in a less complete correction. 3. A more complete correction or overcorrection of the distal epiphyseal plate increased the correction of the angulation of the fracture. These findings strongly indicate that the process of correction of a residual angulation after a healed fracture can be explained in terms of the combined effects of the direction and amount of longitudinal growth at the epiphyseal plate. A trigonometrical equation based on this theory predicted the residual angulations of the fractures, at follow-up, with an error of less than 1 degree.