Parents often notice excessive inward or outward toeing-in infants or toddlers. Excessive in-toeing is more common than out-toeing and is more likely to be caused by benign conditions that usually represent variations of normal development from excessive rotations of the femur, the tibia, or both. In children, in-toeing does not usually cause pain or interfere with development or stability of gait. Therefore understanding the natural progression of femoral and tibial torsion, as well as the changes that occur in hip rotation, is essential for primary care physicians to reassure and advise parents about these common conditions.

Finding older family members with histories of these rotational anomalies is not uncommon. In many instances, a history of a parent who was treated as a toddler with an orthotic device for these conditions can even be found.

Inward rotation of the femur at the femoral neck (femoral anteversion) is greatest at birth (approximately 40 degrees) and gradually declines to adult values of 10 to 15 degrees by age 8 years.

The best position in which to assess the rotation of the lower extremities is with the child in the prone position, the hips fully extended, and the knees flexed to 90 degrees. To measure hip rotation, the lower leg is used as a pointer and the legs are rotated through the axis of the hip joint (Figure 183-14 and Figure 183-15). Until 1 or 2 years of age, the clinical measurement of hip rotation is limited by the physiological tightness of the hip joint capsule, therefore underestimating the degree of femoral anteversion. After the age of 18 to 24 months, measurement of hip rotation is a close approximation of bony femoral rotation, averaging 50 degrees of internal rotation and 40 degrees of external rotation.

The easiest way to assess tibial rotation is to measure the thigh-foot angle, the axis of the foot relative to the axis of the thigh (see Figure 183-16 and Figure 183-17). The normal thigh-foot angle ranges from 0 to 30 degrees of external rotation; therefore an internal thigh-foot angle indicates internal tibial torsion. By age 2 years, children typically walk with the foot turned out relative to the line of progression. A thigh-foot angle of 10 to 15 degrees is normal in adults and older children.

Figure 183-14 Starting position for measuring hip rotation with the hip extended while the child is in the prone position. (Reprinted with permission from Joint Motion Method of Measuring and Recording. Rosemont, IL, American Academy of Orthopedic Surgeons, 1965.)

Figure 183-15 Internal rotation. (Reprinted with permission from Joint Motion Method of Measuring and Recording. Rosemont, IL, American Academy of Orthopedic Surgeons, 1965.)

In-toeing and out-toeing rarely require imaging studies. Evaluation using gait analysis may help in differentiating the cause of the abnormality for individuals with extreme in-toeing or out-toeing.