Pediatric Flexion-Type Supracondylar Humerus Fractures: Predictive Factors for Open Reduction and Impact on the Outcome in a Single Center 10-Year Case Series

BACKGROUND: Flexion-type supracondylar humerus fractures are rare, highly unstable, and often associated with technical challenges. Current literature is limited to small series, and no standardized diagnostic-therapeutic guidelines have been established. METHODS: This retrospective study includes 47 patients with Gartland type II or III flexion-type supracondylar fractures surgically treated between September 2012 and October 2023. Demographic, clinical, radiographic, and functional data were collected to evaluate outcomes after closed or open reduction with percutaneous pinning. Univariate and multivariate model testing were used to analyze associations between fracture severity, surgical timing, rotational or translational deformities, and the need for open reduction and functional outcomes. RESULTS: No major complications occurred. In the multivariate analysis, translational deformity emerged as the sole independent predictor of open reduction (P=0.017). While the Gartland classification and rotational deformities correlated with the need for open surgery in univariate analysis, they were not significant in the final model. Surgical delay beyond 48 hours was not associated with open reduction (P=0.751) or inferior functional outcomes (P=0.327). Regarding functional results, although translational or rotational components were associated with higher QuickDASH scores in the univariate analysis (P=0.036), this significance was not confirmed in the multivariate model. The requirement for open reduction itself was not associated with worse functional outcomes (P=0.173). CONCLUSION: Translational deformity is the most significant predictor of the need for open reduction. However, complex fracture patterns do not independently result in inferior functional outcomes when appropriately managed. Our results suggest that open reduction is a safe option that does not negatively impact long-term function. It should be considered a valid alternative for unstable flexion-type fractures whenever closed reduction fails to restore anatomy. LEVELS OF EVIDENCE: Level IV.