# Secondary Displacement of Forearm Fractures in Children: When to Anticipate Remodeling and When to Intervene?

## TL;DR

The study finds that accepted secondary displacements in children's forearm fractures do not lead to worse long-term outcomes, suggesting a more lenient approach may be safe for certain cases.

## Contribution

The study identifies specific predictors of long-term functional impairment in pediatric forearm fractures and challenges strict reduction criteria.

## Key findings

- Accepted secondary displacements in both metaphyseal and diaphyseal forearm fractures did not lead to worse long-term functional outcomes.
- Complete initial radial displacement, bicortical ulnar fractures, and older age at trauma are predictors of functional impairment.
- A permissive approach to secondary displacements in skeletally immature children may reduce the need for surgical interventions.

## Abstract

What are the main findings?
•Accepted secondary displacements of both metaphyseal and diaphyseal forearm fractures did not lead to worse long-term functional outcomes.•Predictors of long-term functional impairment included complete initial displacement of the radius, bicortical ulnar fractures, and re-fractures for metaphyseal fractures, as well as older age at trauma for diaphyseal fractures.

Accepted secondary displacements of both metaphyseal and diaphyseal forearm fractures did not lead to worse long-term functional outcomes.

Predictors of long-term functional impairment included complete initial displacement of the radius, bicortical ulnar fractures, and re-fractures for metaphyseal fractures, as well as older age at trauma for diaphyseal fractures.

What is the implication of the main finding?
•A more permissive approach to accepted secondary displacements—particularly for metaphyseal fractures in skeletally immature children—may safely reduce the need for repeat manipulations or surgical interventions.•Treatment decisions should be tailored by considering patient age, sex, fracture location, and displacement severity.

A more permissive approach to accepted secondary displacements—particularly for metaphyseal fractures in skeletally immature children—may safely reduce the need for repeat manipulations or surgical interventions.

Treatment decisions should be tailored by considering patient age, sex, fracture location, and displacement severity.

Background/Objectives: Conservative management of pediatric forearm fractures remains challenging due to the high incidence of secondary displacement. Given the remarkable remodeling potential of children’s bones, clinicians must decide whether to rely on natural healing or intervene. This study evaluated whether accepted secondary displacements affect long-term outcomes and sought to identify predictors of functional impairment. Methods: This retrospective cohort study assessed the long-term outcomes of a cohort of 410 consecutive children who presented with 212 distal metaphyseal and 198 diaphyseal both-bone forearm fractures between 2006–2010. In all patients, closed reduction was recommended for ≥50% displacement, ≥15° angulation (<10 years), or ≥10° angulation (10–16 years). Secondary displacements were frequently accepted, anticipating remodeling. We included 316 children (<16 years) with both-bone forearm fractures (147 diaphyseal, 169 distal metaphyseal), representing 77% of the original cohort, for long-term follow-up (mean 7.2 years, minimum 4 years). Functional and radiographic outcomes were compared between accepted secondary displacements and maintained alignments, stratified by fracture location. Multivariate logistic regression identified predictors of long-term functional impairment, defined as ≥15° loss of pro-supination or QuickDASH ≥ 20. Results: In the distal metaphyseal group there were 50 secondary displacements out of 212 fractures, of which 31 were accepted. In the diaphyseal group there were 60 secondary displacements, of which 49 were accepted. At long-term follow-up, patients with accepted secondary displacements had no clinically relevant differences in functional or radiographic outcomes compared with those with maintained alignments across both diaphyseal and distal metaphyseal fracture groups. For distal fractures, complete initial radial displacements, re-fractures, and bicortical ulnar fractures predicted pro-supination loss ≥ 15° or QuickDASH ≥ 20. For diaphyseal fractures, older age at trauma predicted increased risk of pro-supination limitation. Conclusions: Accepted secondary displacements did not worsen long-term outcomes, supporting reconsideration of strict reduction criteria. The substantial remodeling capacity of pediatric bone—especially in distal metaphyseal fractures in skeletally immature children—should be emphasized when making treatment decisions to avoid unnecessary surgical interventions.