O1081: Rate of Refracture Following Removal of Hardware in Pediatric Femur Fractures

Background: Flexible intramedullary nails (FIN) and plates are commonly used for treatment of femoral shaft fractures in pediatric patients, and these implants are often removed after fracture union. However, there is limited data on the rate of refracture following hardware removal. The purpose of this study is to determine the frequency of re-fracture after hardware removal in pediatric patients, to assess the overall rate of hardware removal after femur fracture, and factors associated with both hardware removal and refracture.

Methods: This is a retrospective cohort study that utilized the Pediatric Health Information System (PHIS) database to determine the number of pediatric patients ages 4-10 who underwent surgical fixation of a femur fracture and then had subsequent hardware removal between the years 2015-2019. All patients had a minimum of two-year follow-up to assess for re-fracture. Patients with history of metabolic bone disease, neuromuscular conditions, or pathologic fracture were excluded. Descriptive and univariate statistics were used to determine rate of refracture, rate of removal, and identify any factors associated with these events.

Results: The study included 2371 patients with 2437 femurs that underwent internal surgical fixation via flexible intramedullary nail (FIN) or plating. The mean age of patients at index fracture was 7.2 ± 2.1 and approximately 69.3% of patients were male. Overall rate of hardware removal was found to be statistically significant at 28.9% for FIN and 34.3% for plating (p=0.003) at an average of 620 ± 243 days and 492 ± 463 days, respectively. FIN removal occurred approximately 30 days earlier on average than plate removal (Figure 1). Rate of refracture was also found to be statistically significant at 1.5% for the FIN group and 4.2% for the plating group (p=0.02). Average time to refracture was not found to be statistically significant between the FIN and plating groups (620 ± 243 days vs 492 ± 463 days, p=0.422). We also examined whether patients underwent subsequent procedures outside of hardware removal including revisions, hardware complications, or delayed union. Rate of subsequent procedures were not found to be statistically significant between FIN and plating (2.2% vs 3.2%, p=0.147). Univariate analysis found age, male gender, and census regions to be significant predictors of hardware removal in FIN compared to plating (Table 1).

Conclusion: The estimated rate of hardware removal was 28.9% for FIN and 34.3% for plating. Rate of refracture for patients with at least 2-year follow-up was 1.5% for FIN and 4.2% for plating. This information can be helpful for advising families regarding risks after hardware removal. Additional studies are necessary to further evaluate the factors leading to refracture following implant removal in pediatric femur fractures and provide guidance to decrease the risk of re-fracture and potentially to impact implant choice at initial stage of treatment.