[Three-dimensional ultrasonography and intraoperative navigation:a new application of ultrasonograms in osteotomy of the proximal femur].

Aim: As precise operative control is difficult to achieve, the accuracy of femoral osteotomies can only be estimated. Therefore, a computer-assisted ultrasound navigation system was developed in order to apply an on-line control for femoral osteotomies.

Method: Three ultrasound emitters were fixed on a triangle.