Femur is the thigh bone of the lower limb. Its normal torsion in an adult is towards the body. This normal internal twisting is call femoral anteversion. At birth, femoral anteversion is about 25-40 degrees. Femoral anteversion will decrease at about 1.5 degrees per year as the child grows and normalize at about 15 degrees with skeletal maturity.
How femoral anteversion causes intoeing?
Excessive femoral anteversion causes increase in hip internal rotation. It usually occurs in both hips, more common in females than males. Upon weight bearing, the excessive hip internal rotation appears as intoeing walk or pigeon-toes.
What causes excessive femoral anteversion?
There are 2 main causes for excessive femoral anteversion:
1. Family history
- Parents or siblings presenting with similar gait pattern may explain any unresolving intoeing gait
2. ‘W’ sitting
- extreme hip internal rotation during ‘W’ sitting places large internal torsional force on the femur bone. As the child grows, the torsional force can lead to excessive femoral anteversion.
How to test for excessive femoral anteversion?
Excessive femoral anteversion can be tested in prone.
What is the management for excessive femoral anteversion?
The main medical management prescribed for intoeing walk due to excessive femoral anteversion is observation. Femoral anteversion is known to decrease over years as the child grows. Advises on sitting and sleeping posture is given to encourage external rotation of hips. At age 8-10 years old, the child can consciously control the way they walk by pointing their toes forward. These interventions aim at reducing the internal torsion force experienced by the femur.
Hip strengthening exercises can help encourage outward rotation of the femur to counter the internal femoral torsional forces. For toddlers, games such as backwards walking, climbing stairs and slopes can be use to strengthen the hips. For the older child, specific hip strengthening exercises such as wall squat, bridging and hip abduction exercises can be taught.
Surgical management is reserved for severe hip anteversion deformity. Femoral de-rotation osteotomy can be done. However, complications of surgery include delayed union, infection and avascular necrosis of femoral head.