Disorders of the Femur

Definition

Femoral anteversion is defined by the angle of the femoral neck in relation to the femoral shaft in the coronal plane ( Fig. 17.1 ). The degree of anteversion is greatest in infancy and gradually decreases as skeletal maturity is approached. ^, In infants, the mean degree of anteversion is approximately 40 degrees, but decreases to 16 degrees by adulthood. When anteversion is increased or when it fails to decrease with age, the gait is altered and the person walks with the hip internally rotated. This rotation produces a gait in which the patella is medially rotated in stance phase and the foot is also internally rotated, resulting in intoeing. Some individuals have excessive internal rotation of the tibia, which increases the degree of intoeing; others have external rotation through the tibial segment, which reduces intoeing. The latter combination produces an awkward gait that is accentuated during running; the feet swing out to the side in swing phase.

Clinical Features

Children with excessive femoral anteversion come to medical attention because of an intoeing gait. This gait may be noted when the child first begins to walk or it may be noted later in childhood, when the intoeing fails to resolve. Parents also note that the child trips on the intoed feet and that the intoeing is more prominent with running. The condition is not painful.

Physical examination confirms the diagnosis ( Fig. 17.2 ). The knees are internally rotated in the stance phase of gait and the feet follow unless external tibial torsion is present. There is excessive internal rotation of the hips and decreased external rotation. This is best demonstrated in the prone position ( Fig. 17.3 ). The degree of tibial torsion, which is measured by the thigh-foot angle, is also noted in the prone position. In severe cases, there may be 90 degrees of internal rotation of the hip without any external rotation.