[Angular and torsional malalignments of the paediatric knee joint].

backgroundAbnormal angular and torsional alignment of the lower extremities during growth are a common reason for consultation of a paediatrician or orthopaedist. There is often uncertainty about the pathological value of these abnormalities and the need for treatment, even among specialists. In the course of physiological growth and development processes, the axial and torsional alignment of the legs sometimes change considerably and in characteristic patterns. DIAGNOSTICS: The ability to assess whether abnormal angular or torsional alignments of the lower limb in the course of growth should still be regarded as normal or already as pathological, depending on age and gender, is essential for the treating physician and requires precise knowledge of the physiological development processes and the tolerable limits in all three spatial dimensions. TREATMENT: After careful explanation to the frequently concerned parents, a restrictive approach with observation of the spontaneous course of correction on the basis of regular clinical check-ups makes sense in the majority of cases. Pathological deviations from the physiological conditions are rare overall, can be idiopathic or of secondary origin and should be further clarified diagnostically using imaging procedures. As conservative measures are ineffective, pronounced angular and/or torsional deformities of the legs requiring treatment can only be corrected by surgical intervention, even in children and adolescents. The surgical treatment modalities available are varied and differ in terms of their invasiveness and complication profile, depending on the localization, type and severity of the deformity, as well as the age and possible concomitant diseases of the affected child or adolescent.