Femoral neck anteversion: values, development, measurement, common problems. 
The femoral neck anteversion angle is an important factor for hip stability and normal walking.  It is multifactoral result of evolution, heredity, fetal development, intrauterine position, and mechanical forces.  Abnormal FNA sometimes can be associated with many clinical problems ranging from harmless intoeing gait in the early childhood, to disabling osteoarthritis of the hip and the knee in the adults.  In most cases is associated with minor functional problems in children during growth, but cause a concern in parents for children future.  The child must be examined carefully and an accurate diagnosis must be established.  The most important part of care is observation of the children.  If abnormal femoral neck anteversion produces severe functional disability, derotational osteotomy should be done, but delayed until late childhood.