[Determining rotational errors of the femur by axial computerized tomography in comparison with clinical and conventional radiologic determination].

58 patients, suspicious to have a rotation deformity of the femur, were treated between 1981 and 1988 at our hospital. To compare the value of diagnostic methods in measuring the degree of malrotation we estimated this degree using clinical tests and calculated the anteversion of the femoral neck, taking radiographs in the technique of Dunn and Rippstein and a modified method of computed tomography. Surprisingly only in twelve cases the direction of malrotation, not to consider the degree, with all three methods was corresponding. Clinical evaluation only in cases with extreme deformity produces clear results. Maintaining the exact position of the patient, necessary to get reproducible results using conventional X-ray technique, was impossible in most cases of elderly patients with postraumatic joint-stiffness and malalignment. Determination of femoral neck anterversion by means of CT is a quick, reproducible method to calculate the degree of rotation deformation, insensitive to the position of the patient's extremities as far as there is no motion during the time of scan.