[Torsion and torsional development of the lower extremities].

BACKGROUND: Torsion is a frequent reason for consultation in paediatric orthopaedics. Torsion of the femur and the tibia in children change during growth. Depending on the age and possibility for compensation, this can be reflected in the gait pattern. Different causes can affect the normal development of torsion. DIAGNOSTICS: In the context of paediatric orthopaedic assessment, the distinction between physiological and pathological torsion is essential. In addition to the patient history and observation of the gait pattern, as well as a detailed clinical examination, additional imaging techniques are used (Rippstein/Dunn, torsional CT/MRI, EOS). The dynamic effect of abnormal torsion on gait is evaluated by instrumented 3D gait analysis. PATHOGENESIS: Evidence for the long-term significance of torsional deviations and the risk of consequential damage are low. Isolated increased femoral anteversion without accompanying hip dysplasia is fundamentally harmless, corrects during growth and only rarely needs correction in the case of ongoing disturbing gait or knee problems. In contrast, retroversion is likely indicate the development of pre-arthritic deformity and should be observed and treated more carefully. Tibial torsion shows great variability and may influence the development of femoral torsion. Torsional deformities in children with neurological or syndromal conditions are differentiated as when the biomechanical effects of torsions on their gait function are generally more marked and therefore treatment is more frequently necessary. THERAPY: Conservative treatments cannot be expected to have an effect on the condition of the bones. Correction can only be achieved surgically with a rotational osteotomy. A simple principle underlies the technique, whereas indication and timing are challenging.