Tibial torsion is a rotation of the tibia on its longitudinal axis relative to the transverse axes of the knee and ankle joints.

Pathological degrees of internal and external tibial torsion are found only in association with deformities of the feet, ankles, knees, and hips or as a result of improperly applied casts, braces, or Denis Browne splints.

The incidence of internal tibial torsion is 12% at birth, gradually diminishing to near 0% at 2 years of age.

During fetal life, the tibia is rotated inward on its longitudinal axis relative to the transverse axes of the knee and ankle joints. At birth, it reaches a neutral position. External tibial torsion develops in most babies shortly after birth and is almost universal by age 2 years, reaching 20 degrees of lateral torsion by the time walking is fully established and 23 degrees by adulthood.

The degree of internal and external tibial torsion can be determined by observing the relative position of the medial and lateral malleoli while the child is sitting on the edge of a table or chair with legs dangling, the patellae facing forward, and the feet in their relaxed position. The medial malleolus is placed posterior to the lateral malleolus in internal tibial torsion and anterior to it in external torsion.

Figure 183-16 Thigh-foot angle: normal range. (Alexander IJ. The Foot: Examination and Diagnosis. New York, NY: Churchill Livingstone; 1990. Copyright © 1990, Elsevier, with permission.)

Figure 183-17 Bilateral internal tibial torsion. (Alexander IJ. The Foot: Examination and Diagnosis. New York, NY: Churchill Livingstone; 1990. Copyright © 1990, Elsevier, with permission.)

The degree of torsion can be measured exactly either radiographically or with special instruments but is not required in most cases.

Treatment of primary internal tibial torsion is not required in most cases. Occasionally, if a child trips on his or her feet and falls frequently, or if parents are unduly concerned over toeing-in, then passive stretching exercises (externally rotating the foot at the ankle), corrective shoes (Thomas heel, longitudinal arch pad, inner-heel, and outsole wedges), or application of torque heels may be prescribed. Denis Browne splints should not be used without orthopedic consultation because they may create abnormal stress on the hip joint. Derotation osteotomy of the tibia rarely is required and then almost always when tibial torsion is associated with other orthopedic anomalies of the lower extremity. The primary care physician can usually observe children with tibial torsion. A referral is important if the child has extreme rotation, significant asymmetry of the torsion, a sudden proximal tibial deviation, or a condition that does not follow the typical pattern of improvement with growth.