Long-term implant retention after impacted elastic stable intramedullary nailing in pediatric diaphyseal forearm fractures: a retrospective cohort study

BACKGROUND AND PURPOSE: In elastic stable intramedullary nailing (ESIN) for forearm fractures, nail protrusion may cause irritation-related implant removal. The primary aim was to evaluate implant retention after nail impaction, and secondarily to assess secondary procedures, complications, and protrusion as a predictor of removal. METHODS: We analyzed a retrospective cohort of children with diaphyseal forearm fractures treated with impacted ESIN between 2017 and 2024. Implant retention was defined as no nail removal at record review. Secondary procedures were unplanned operations, while complications were adverse events managed conservatively. Radiographic nail protrusion was measured as extraosseous nail length and evaluated using receiver operating characteristic analysis to predict irritation-related implant removal. RESULTS: 160 children with diaphyseal forearm fractures were included. At a mean observation time of 5 years, 132/160 children retained their implants (83%, 95% confidence interval [CI] 76-88). Secondary procedures occurred in 30/160 patients (19%, CI 13-26), most commonly irritation-related implant removal (10%, CI 6-16) and refracture (6%, CI 3-10). Complications occurred in 19/160 patients (12%, CI 7-18), including superficial radial nerve symptoms (7/160; 4.4%) and irritation without implant removal (6/160; 3.8%). A protrusion threshold of 3.3 mm predicted irritation-related implant removal (AUC 0.79, CI 0.71-0.86; sensitivity 100%, CI 83-100; specificity 55%, CI 49-61). No irritation-related removals occurred below this threshold. CONCLUSION: Impacted ESIN was associated with high long-term implant retention, although secondary procedures and complications occurred in about one-third of the patients. A protrusion threshold of 3 mm was linked to irritation-related removal and may guide implant retention.