Femoral Anteversion

GENESIS

Femoral rotation describes the normal twist present in the femur, and excessive femoral anteversion results from medial rotation of the femur after birth. Normal rotation in direction and magnitude is termed version , with normal values determined according to age. Abnormal rotation is termed torsion , and the rotation of a given bone is determined by the angle between the axis of the head and neck of the femur and the axis of the distal condyles at the most posterior points. If the angle between the proximal and distal axes is positive (+), the femur is considered “anteverted,” and if it is negative (−), the femur is “retroverted.” Excessive femoral anteversion is the most common cause of in-toeing that develops after age 3 years, and it usually resolves spontaneously by late adolescence. Femoral anteversion can be familial, is more common in females, and is usually symmetric. Use of special shoes or bracing does not hasten resolution, but continuation of adverse sleeping or sitting positions may slow or prevent progress. Surgery consisting of femoral derotation osteotomy is usually only contemplated in children older than 8 years with insufficient spontaneous correction, particularly diplegic children with cerebral palsy. The rotational profile of the lower limb was analyzed in 1319 healthy children, and femoral anteversion was higher in females and markedly correlated with age in both genders (1% in 6-year-old females and 8.5% in 9-year-old females). Among 950 children studied for spontaneous regression of femoral neck anteversion, these children were divided into three groups: (1) children with normal gait, (2) children with in-toeing gait, and (3) children with an out-toeing gait. On the third examination at 14 years of age, children with an in-toeing gait decreased from 12.8% to 1%, while the number of children with an out-toeing gait did not change significantly during the examination period.

Excessive in-toeing during the second year is usually caused by tibial torsion, and severe in-toeing may be the result of a combination of causes. Out-toeing is much less common than in-toeing. Femoral retroversion can be caused by external rotation contracture of the hip. It becomes apparent before walking when the infant stands with feet turned out nearly 90 degrees in a “Charlie Chaplin” stance. It occurs more commonly in obese children, and when unilateral, it is more commonly right-sided. Another cause of out-toeing in the obese child is a slipped capital femoral epiphysis, which requires hip radiographs if suspected. If femoral retroversion persists beyond 2–3 years of age, referral to an orthopedist is indicated.