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

Abstract

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. Retrospective comparative study. Multicenter, children's hospital and general hospital. 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. Thirty-six children were treated by minimal invasive plate osteosynthesis (MIPO), and elastic stable intramedullary nail fixation (ESIN) was used in 51 children. 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. 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). 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. Therapeutic Level III. See Instructions for authors for a complete description of levels of evidence.