Tibial Overgrowth and Ipsilateral Femoral Overgrowth after the Fracture of Tibial Shaft in Children.

Abstract

Background: Overgrowth of the limb often occurs after pediatric tibial shaft fractures; however, risk factors for this phenomenon differ across studies. In addition, overgrowth of the ipsilateral femur is not well known. This study aimed to analyze ipsilateral femoral overgrowth after pediatric tibial shaft fracture and to compare the risk factors for tibial and ipsilateral femoral overgrowth.

Methods: Among the 85 patients who were diagnosed with tibial shaft fractures between January 2012 and December 2022 under the age of 14 years and followed up for more than a year, 6 patients who had missing initial plain radiographs, associated fractures or bone lesions in the lower extremities, or reoperation due to complications were excluded. After exclusion, 79 patients were included in this retrospective study. Medical records and radiographic data were collected, including information on tibial overgrowth, femoral overgrowth, and leg-length discrepancy (LLD) at the latest follow-up. Age, sex, laterality, fracture stability, fracture location, fracture comminution, fibular involvement, open or closed fractures, fracture site shortening, and treatment type were selected as variables for univariate and age-sex adjusted multiple logistic analyses to identify risk factors for tibial and femoral overgrowth.

Results: Femoral overgrowth occurred in 35 patients (44%). Among the 17 patients with LLD ≥ 1 cm, 13 patients (76%) showed femoral overgrowth, and the proportion of femoral overgrowth in LLD was 25% (interquartile range, 18%-31%). The distal location was identified as a risk factor for femoral overgrowth; however, for tibial overgrowth, length-stable fracture pattern, fibular involvement, operative treatment, and fracture site shortening were identified as risk factors.

Conclusions: Femoral overgrowth can occur after pediatric tibial shaft fractures; however, its contribution to the LLD was not significant. The risk factors for tibial and femoral overgrowth differed, which may be the result of different mechanisms that affect the overgrowth of the fractured tibia and the ipsilateral femur.