Overlooked valgus bowing deformity in pediatric tibial shaft fractures with/without fibular involvement: Cause residual valgus alignment in 2-year follow-up

Abstract

Background: Children with a tibial shaft fracture often present with valgus malalignment, even when anatomical reduction had been achieved at the fracture site. Pediatric bony structure has more elastic bones than that of adults, it can cause bowing deformity. Therefore, we evaluated pediatric tibial shaft fracture for the presence of bowing deformity, associated risk factors, and its clinical significance. Hypothesis: There is an overlooked bowing deformity in pediatric tibial shaft fracture. Patients and methods: Fifty-seven tibial shaft fracture patients aged 2 to 15 years with Risser stage 0 were retrospectively reviewed. Clinicoradiologic factors and radiographs taken within 3 post-traumatic months and at 2 years were assessed. To evaluate the tibial bowing deformity, the tibial interphyseal angle and tibial shaft angle were measured, and their differences were calculated as a tibial bowing angle. Results: Multivariate analysis revealed the tibial shaft fracture with fibular involvement is significantly associated with a higher initial tibial bowing angle (valgus deformity). The tibial bowing angle did not change over 2-year follow-up. A high initial tibial bowing angle (>= 5 degrees) was a significant risk factor for the persistence of valgus malalignment. Discussion: Pediatric tibial shaft fractures with/without fibular involvement carry the risk of valgus bowing deformity, which may not develop during post-traumatic growth but may be present at the time of injury. The risk is high if the tibial fracture is accompanied by a fibular fracture. This tibial deformity presents limited remodeling potential at 2-year follow-up. Level of evidence: IV; retrospective study.