Femoral Anteversion: What You Need to Know
- Femoral anteversion describes the inward rotation of the femur bone in the upper leg.
- Femoral anteversion occurs in up to 10 percent of children; 99 percent of cases resolve over time without the need for surgery.
- In many cases, the abnormal rotation of the femur develops while the fetus is growing in the womb.
- In children older than 3, femoral anteversion is the most common cause of in-toeing (walking with feet angled toward each other).
What is femoral anteversion?
The femur is the long bone that connects the hip joint to the knee joint. Anteversion means “leaning forward.” Femoral anteversion is a condition in which the femoral neck leans forward with respect to the rest of the femur. This causes the leg to rotate internally, so that the knee and foot twist toward the midline of the body.
Some degree of rotation of the femur is always present as kids grow. It is a cause for concern only if it significantly differs from the average rotation in children of the same age. Typically, children are born with 40 degrees of femoral anteversion. It gradually decreases to 10 to 15 degrees at adolescence and generally improves with further growth.
What causes femoral anteversion?
Femoral anteversion forms during development of the fetus in the womb. It typically affects both legs and is more common in girls. The exact mechanism behind femoral anteversion is unknown. It is thought to be related to genetic factors and the position of the fetus in the uterus.
What are the signs and symptoms of femoral anteversion?
Femoral anteversion is usually most noticeable in children between the ages of 4 and 6. You may notice that your child is walking with the toes turned inward. This may also make the legs look bowed. Children with femoral anteversion may trip and fall more than their peers, but the condition is rarely painful.
Femoral Anteversion Diagnosis
Femoral anteversion is diagnosed through observation and examination. A specialist will observe your child to see if the toes and/or kneecaps turn inward as he or she walks. The physical exam is typically conducted with the child laying down. This position helps determine the degree of the femur’s internal rotation.
Femoral Anteversion Treatment
Femoral anteversion usually improves as a child grows. No treatment is necessary if the degree of rotation is within the healthy range.
Surgery is rarely needed for femoral anteversion. It may be recommended to older children (age 8 or older). And the anteversion has to be severe enough to impair walking, running or other functions. The surgery is called a femoral derotation osteotomy. Osteotomy means that a surgeon cuts the bone — the femur in this case. Then the femur is rotated and fixed in a more anatomically natural position.
How will a child with femoral anteversion do long term?
Anteversion usually corrects itself by early adolescence. Studies show that these children don’t have an increased risk of hip or knee arthritis or athletic difficulties later in life.