Rigid intramedullary nailing of adolescent tibia fractures: Less angulation and unplanned implant removal rates with equivalent patient reported outcomes compared to flexible intramedullary nails

Objective: Adolescent tibial shaft fractures can be treated with flexible or rigid intramedullary nails. Flexible intramedullary nails (FIN) avoid the proximal tibial physis but may lack stability. This study compares outcomes and skeletal maturity in adolescents treated with flexible versus rigid nailing of tibial shaft fractures. Methods: Patients aged 11–16 who had tibial intramedullary nailing at a pediatric level one trauma center from 2011 to 2021 were studied. Data on age, injury mechanism, complications, angulation, OR trips, and skeletal age (determined by the modified Fels scoring system) were recorded. PROMIS was used to collect patient-reported pain and mobility scores. Results: 37 patients underwent FIN and 23 patients underwent RIN. Average age was greater in RIN patients (15.2 vs 13.2, p < .001). All RIN patients had partial or complete closure of the proximal tibial physis compared to 21.6 % in FIN. Coronal and sagittal angulation at final follow up was greater in the FIN group (p = .049, p = .002). Implant removal was more common in the FIN group (75 % vs 13 %), with 20 (54 %) unplanned implant removals in the FIN group and 3 (13 %) in the RIN group (p = .0015). OR trips, complications, and time to weight bear did not differ between groups. There were no significant differences in PROMIS scores. Conclusions: RIN for adolescent tibia fractures results in similar pain and mobility scores but with less angulation and fewer unplanned implant removals compared to FIN. Further studies are needed to determine the safe skeletal maturity for RIN without significant physeal injury given this potential benefit.