Measuring anteversion and femoral neck-shaft angle in cerebral palsy.

Femoral anteversion was measured by computed tomography (CT) in 40 children with cerebral palsy, however an accurate measurement was possible in only 59 of the 80 hips. Flat-surface measurement of anteversion was possible in 72 of 80 hips by CT, and in 36 of 40 hips by ultrasound. A high neck-shaft angle correlated with an inability to measure anteversion by CT. Measuring by ultrasound allowed subjects to be positioned in internal rotation and in this way accurate measurements of neck-shaft angles were obtained.