Risk factors for redisplacement of pediatric distal forearm and distal radius fractures

Abstract

Background: Fractures of the distal forearm and distal radius represent the most common types of fracture in the pediatric population, with the majority treated by closed reduction and cast. Redisplacement has been known to occur in up to 39% of cases. There have been numerous risk factors and radiologic indices put forward as methods of predicting redisplacement, but this topic remains a matter of debate. This retrospective study aims to further assess the significance of the many factors in redisplacement after treatment with closed reduction.

Methods: This retrospective study included 155 children with distal radius and forearm fractures. Age, sex, location of fracture, angulation, displacement, an associated ulna fracture, obliquity of fracture, and accuracy of reduction were measured for assessment as potential risk factors. In addition, the cast index, padding index, Canterbury index, second metacarpal-radius index, gap index, and 3-point index were measured on postreduction radiographs.

Results: Redisplacement occurred in 33 of the 155 cases (21.3%). Initial displacement and accuracy of the reduction were identified as significant risk factors for redisplacement. Initial displacement of >50% (of the radius width) was significantly associated with redisplacement (odds ratio of 5.4). Failure to achieve anatomic reduction was significantly higher in the redisplacement group (odds ratio 3.9). The only radiologic index that differed significantly between groups was the cast index, with more patients without redisplacement meeting the cut-off value (60% vs. 32%, P=0.010).

Discussion: Initial displacement of >50% and inability to achieve anatomic reduction are major risk factors for redisplacement. Given its effectiveness and ease of clinical application, the cast index remains the most useful measure of cast molding.

Level of evidence: Level II--Retrospective prognostic study.