A retrospective study of treatment of genu valgum/varum with guided growth: Risk factors for a lower rate of angular correction

The rate of angular correction (ROAC) is very unpredictable and may be affected by various factors in the treatment of genu valgum and varum by means of guided growth. The purpose of this study was to assess the ROAC in cases from our institution and to identify risk factors associated with the occurrence of lower ROAC. We retrospectively reviewed the chart records of 68 patients undergoing guided growth with figure-eight plate for the correction of genu valgum and varum. Based on the data from these patients, the annual increment of physeal growth was calculated and compared with data from the Anderson chart. The associations between patient characteristics and ROAC were evaluated with the use of univariate logistic regression. The mean rate of femoral angular correction was 10.29 degrees/year, while the mean rate of tibial angular correction was 7.92 degrees/year. In a univariate logistic regression analysis, the variables associated with a higher risk of lower ROAC included non-idiopathic coronal deformity of the knee (odds ratio = 13.58, p < 0.001) and body weight at or above the 95th percentile for children (odds ratio = 2.69, p = 0.020). Obesity and non-idiopathic coronal deformity of the knee are risk factors for lower ROAC. It is still uncertain whether severity of deformity, race, and operative procedure have a substantial effect on the rate of correction. Level III evidence.