Fractures of the proximal segments of the pediatric distal radial metaphysis exhibit less angular stability than fractures of the distal segments.

The distal part of the forearm is divided into the physis, metaphysis, diaphyseal metaphyseal junction (DMJ) and diaphysis. The treatment of radial DMJ fractures is challenging because this region has diaphyseal characteristics. We speculated that the stability of metaphyseal fractures could vary depending on their proximity to the DMJ or physis. Our study aimed to investigate the stability of pediatric distal radius fractures in the physis, metaphysis and DMJ. Ninety-five patients were classified into three groups: group D, fracture line located within 1/2 of the width of the radius (WOR) from the physis; group M, fracture line located between 1/2 and 1 WOR from the physis; and group P, fracture line located between 1 and 2 WOR from the physis. We measured sagittal angulation and coronal angulation. A correction loss of less than 9° was defined as a 'stable reduction' outcome and one greater than 10° as a 'loss of reduction' outcome. The correction losses for sagittal angulation were significantly greater in groups M and P than in group D. The correction losses for coronal angulation were significantly greater in group P than in groups D and M. The incidence of 'loss of reduction' outcomes was significantly higher in groups M and P than in group D. The proximal segments of distal radial metaphyseal and DMJ fractures showed less angular stability than distal segments.