Summary External Tibial Torsion is a rare developmental condition in young children caused by abnormal external rotation of the tibia leading to an out-toeing gait. Diagnosis is made clinically with a thigh-foot angle measuring greater than 20 degrees of external rotation. Treatment is generally nonoperative with rehab and activity modications for the majority of patients. Surgical management is indicated for children older than 8 years of age with external tibial torsion greater than three standard deviations above the mean ( >40 degrees external). Epidemiology Anatomic location may be bilateral but if unilateral most commonly involves the right lower extremity. Etiology Associated Conditions miserable malalignment syndrome a condition defined as external tibial torsion with femoral anteversion Osgood-Schlatter disease osteochondritis dessicans early degenerative joint disease an association between external tibial torsion and early degenerative joint disease has been found neuromuscular conditions may be found with neuromuscular conditions such as myelodysplasia and polio Anatomy Normal development tibia externally rotates on average 15 degrees during early childhood femoral anteversion decreases on average 25 degrees during this time as well Presentation Symptoms anterior knee pain caused by patellofemoral malalignment Physical Exam thigh-foot axis measurement best way to evaluate tibial torsion login to view 2 more bullets technique login to view 2 more bullets transmalleolar axis measurement another way to evaluate tibial torsion login to view 2 more bullets technique login to view 4 more bullets Imaging Usually none required. Treatment Nonoperative rest, rehab, and activity modifications indications login to view 1 more bullet Operative supramalleolar derotational osteotomy or proximal tibial derotational osteotomy indications login to view 2 more bullets Techniques Supramalleolar rotational osteotomy technique osteotomy login to view 3 more bullets plate fixation login to view 1 more bullet intramedullary fixation login to view 1 more bullet Prognosis Since the leg externally rotates with physical growth, this deformity usually worsens during late childhood and early adolescence.