"Crooked and Short Legs" in Childhood

For decades, paediatric orthopaedics have been analysing the developmental changes in axes, length and torsion in children. Throughout the entire growth period, these relationships change continuously. Understanding them and being able to classify them as physiological or pathological is essential. If, during growth, greater axis deviations or limb length discrepancies arise, minimally invasive growth modulation can often be performed.Guided growth using staples or screws is among the most well-established method. By far the most common indication is the axis deviation in the frontal plane, such as valgus or varus deformities of the knee joint. In these cases, the growth plates around the knee are partially restrained on one side, leading to increased growth on the opposite side and thus gradually correcting the deformity over time. Knee extension deficits or reduced osseous dorsiflexion of the ankle joint can also be improved through growth modulation.Leg length discrepancies can likewise correct themselves over time through inhibition of the growth plates at the knee. Both temporary and permanent methods are used, each with their respective advantages and disadvantages. Torsional deformities, however, remain a problem that has not yet been fully resolved. Although various approaches to modulation exist, no concept has yet become established in clinical practice.All guided growth methods share one common feature: their dependence on growth and the associated uncertainty in prediction. Clinical experience, as well as various models that use chronological or skeletal age, can help determine the optimal timing of intervention.Through guided growth, angular deformities of the legs can be corrected using a minimally invasive procedure making use of the childrens' natural growth.