Overgrowth of the Femur After Internal Fixation in Children With Femoral Shaft Fracture-A Multicenter Study

Abstract

Objectives: To evaluate overgrowth after internal fixation for pediatric femur fracture and to identify any factors related with overgrowth in terms of fracture type and fixation method. Design: Retrospective comparative study. Setting: Multicenter, children's hospital and general hospital. Patients/Participants: Eighty-seven children between 4 and 10 years of age were included. Length-stable fracture was noted in 49 children, and length-unstable fracture was found in 38 children. Intervention: Thirty-six children were treated by minimal invasive plate osteosynthesis (MIPO), and elastic stable intramedullary nail fixation (ESIN) was used in 51 children. Main Outcome Measurements: The degree of overgrowth after internal fixation compared to fracture type, fracture site, and surgical method. Multivariable logistic regression analysis was conducted to identify factors related with overgrowth. Results: The average overgrowth of the femur was 10.5 +/- 7.3 mm. There was no patient who required correction for final leg length discrepancy (>2 cm). There was no significant difference in overgrowth between ESIN (9.9 +/- 7.2 mm) and MIPO (11.2 +/- 7.6 mm) (P = 0.417). Overgrowth was similar among length-unstable fractures (12.3 +/- 7.4 mm) and length-stable fractures (9.2 +/- 7.0 mm), although it was statistically greater in length-unstable fractures (P = 0.048). In the MIPO group, length-unstable fractures were associated with an increased log odds of 6.873 for overgrowth of the femur (P = 0.042). Conclusions: Femur overgrowth after internal fixation seems to not be a clinically significant problem, regardless of whether that be for length-stable or length-unstable fractures and whether they were treated by MIPO or ESIN. Length-unstable fracture may be a risk factor for overgrowth in children. However, the difference is very small, and the postoperative overgrowth would likely not be a significant factor in deciding the surgical plan.