Predictors for losing reduction after reposition in conservatively treated both-bone forearm fractures in 38 children

Alignment loss after reduction and cast immobilisation of angulated and/or complete displaced forearm fractures is challenging. Many authors have tried to describe risk factors and create indices (initial angulation, initial complete displacement, lack of anatomic reduction, cast and padding index) in order to identify those fractures that are prone to losing their alignment during treatment.

This retrospective case-control study included children sustaining both-bone forearm fractures treated by closed reduction and cast immobilisation. Basic characteristics were recorded and radiographs evaluated to measure displacement and angulation before and after reduction, cast index and padding index. The primary outcome was loss of reduction during the immobilisation period.

Group A consisted of 22 patients in whom >5° reduction loss was seen during cast immobilisation. Group B consisted of 16 patients with <5° reduction loss. After multivariate analyses we found group A included more broken cortices, with a statistically significant higher number of initial displaced fractures (p < 0.001 and p = 0.010) and residual displacement (p = 0.022). The cast and padding index did not differ significantly between groups (p = 0.77 and 0.15 respectively).

Cast and padding index did not correlate well as predictor of alignment loss, although in this study cortical stability seemed more important towards predicting alignment loss.