Die sonographische Messung der Schenkelhalsantetorsion

Abstract

We introduce a simple method of sonographic determination of femoral neck anteversion in children with which the even difficult angels in terms of measurement, those up to 70 degrees, can be measured with sufficient reliability: The examination was done with a defined internal 40 degree rotation of the legs reached by a supporting wedge. We proved this method on 55 children's hips of which we already had an existing radiologic determination of the anteversion angle. Compared to the radiological results we found an average deviation of 3.6 degrees (standard deviation = 3.2).

Femoral anteversion: significance and measurement

“…Left panel adapted from Elke et al . (1991). Frontal view of different ultrasound approaches: the head‐trochanter line approach features the peak of the red ‘head’ section BD and the peak of the red ‘trochanter’ section AC (Upadhyay et al, 1987; Terjesen and Anda, 1987; Aamodt et al, 1995; Keppler et al, 1999).…”

“…Comparisons of US with different imaging techniques such as radiography, MRI and CT have shown mean differences of FNA of 0.5° to more than 10° (Terjesen and Anda, 1987; Upadhyay et al ., 1987; Elke et al ., 1991; Aamodt et al ., 1995; Tomczak et al ., 1995; Ehrenstein et al ., 1999; Keppler et al ., 1999; Kulig et al ., 2010; Passmore et al ., 2016). US has been shown to have lower inter‐ and intra‐observer reliability than MRI or CT for the 2D methods (Tomczak et al, 1995) but appears more reliable in dried bones (Upadhyay et al, 1987).…”

“…Some methods place the probe horizontally and measure the inclination on the image on the screen or later on the printed image Moulton and Upadhyay, 1982;Upadhyay et al, 1987;Elke et al, 1991) but results are not consistent at high angles of anteversion (Phillips et al, 1985;Terjesen and Anda, 1987;Elke et al, 1991) where the distal part of the femoral neck becomes deeper and harder to image. To adjust for this issue, others use inclinometers mounted on the probe (Terjesen and Anda, 1987;Terjesen et al, 1993;Aamodt et al, 1995;Ehrenstein et al, 1999) and take the measurement when the chosen features are showing horizontally on the screen, or use additional hardware to place the femur in internal rotation (Elke et al, 1991). Free-hand US couples the ultrasound with video or motion capture localisers (Keppler et al, 1999;Keppler et al, 2007;Świątek-Najwer et al, 2014;Passmore et al, 2016;Greatrex et al, 2017).…”

“…Several features have been used to determine the proximal femur axis: the head-trochanter tangent (Upadhyay et al, 1987;Aamodt et al, 1995;Keppler et al, 1999), the femoral neck (Clarac et al, 1985;Ehrenstein et al, 1999), and the intertrochanteric plane (Elke et al, 1991;Kulig et al, 2010;Passmore et al, 2016) (Figure 9).…”

“…The features used to draw the inter-condyle axis are the posterior condyles (Keppler et al, 1999), the epicondyles (Moulton and Upadhyay, 1982, the epicondyles, and the anterior condyles (Upadhyay et al, 1987) or the anterior condyles only (Ehrenstein et al, 1999). The posterior condylar line can also be inferred using the tibia as a perpendicular reference (Terjesen and Anda, 1987;Elke et al, 1991;Terjesen et al, 1993;Günther et al, 1996), bearing in mind that varus or valgus knee deformation could affect the end result.…”