Guided growth for idiopathic genu valgum: analyzing the incidence and risk of rebound

This study aimed to determine the incidence rate of rebound and associated factors in pediatric patients with idiopathic genu valgum treated with guided growth using tension-band plates. Patients with idiopathic genu valgum treated with tension-band plates between January 2013 and April 2023 were retrospectively analyzed. Demographic data and radiological measurements, specifically mechanical axis deviation, were evaluated at three time points: at the time of surgery, at the time of implant removal, and 1 year after implant removal. To evaluate factors associated with the risk of rebound, a mixed-effects logistic regression model was used. A total of 46 patients (91 limbs) were analyzed. The mean age at the time of surgery was 12.3 ± 1.28 years. The mean follow-up period after implant removal was 28.3 ± 19.4 months. The mean time to achieve mechanical axis correction was 10 months. The incidence of rebound was 67% [95% confidence interval (CI): 51-80]. A higher rate of angular correction during guided growth, exceeding 2.95 mm/month per limb, was significantly associated with an increased likelihood of rebound (odds ratio: 2.36; 95% CI: 1.1-5.1; P = 0.002). The findings of this study highlight that a significant proportion of pediatric patients with idiopathic genu valgum treated with guided growth experienced rebound after implant removal. Nevertheless, the rate of requiring surgical revision remained relatively low. Importantly, we established a significant association between a higher rate of angular correction and an increased likelihood of rebound effect.