Computed tomography for femoral and tibial torsion in children with clubfoot.

Forty-seven children with 70 clubfeet had computed tomography studies performed to determine the degree of femoral, tibial, and total limb torsion in both lower limbs. The total limb torsion angle (angle between the axis of the femoral neck and the axis of the ankle), which describes the relationship between femoral and tibial torsion, was used to evaluate the whole rotational deformity of the lower limb. The children were between the ages of 2 and 10 years (mean, 5 years) at the time of the computed tomography study. The mean femoral torsion was 25 degrees in the limbs with a clubfoot and 23 degrees in the contralateral limbs of patients with a unilateral clubfoot. The mean tibial torsion was 25 degrees in the limbs with a clubfoot and 24 degrees in the contralateral limb of patients with a unilateral clubfoot. The authors observed decreases of anterior femoral torsion corresponding to increases in age, consistent with the observations made by other authors of studies of children without clubfoot. External tibial torsion increased with age, with similar values in limbs with and without clubfoot. Ten limbs (nine with clubfoot, one without clubfoot) had femoral torsion greater than the means plus one standard deviation and 12 limbs (eight with clubfoot, four without clubfoot) had tibial torsion less than the means minus one standard deviation. The authors found four limbs (all with clubfoot) in three patients with lower than the mean minus one standard deviation of the total limb torsion angle (intoeing). Overall, there was no appreciable difference in the amount of femoral or tibial torsion in limbs with and without a clubfoot.