The normal development of tibial torsion

Objective: Pathological rotation of the leg is a well-known problem in paediatric orthopaedics. In this study the normal development of tibial torsion during growth was evaluated by computed tomography (CT). Design: Seventy-eight normal individuals (52 children, 26 adults) aged 3-51 years were examined with CT. In axial scans the angle between a line tangential to the posterior part of the femoral condyles and the intermalleolar line, a line through the centre of the lateral and medial malleolus, was measured. The radiation exposure was evaluated and accepted by The National Department for Radiation and the Regional Committee for Ethics in Science. Results: CT showed that the average lateral torsion of the leg at the age of 4 years was 28 degrees with an individual variation of 20 degrees -37 degrees. Later the increase in tibial torsion was on average 1 degrees /year until 10 years of age and, thereafter, 4 degrees until maturity when the mean lateral torsion was 38 degrees (18 degrees -47 degrees). Conclusion: Tibial torsion in children mainly develops during the first 4 years of life. After this the increase was of less clinical significance.