[Inter- and intraobserver reliability in Graf's sonographic hip examination]

Inter- and intraobserver reliability and learning curve using Graf's ultrasonographic hip examination were assessed.

189 participants of the basic, advanced and final courses on hip ultrasound using the Graf method (DEGUM) were asked to answer a questionnaire and to measure 34 normal and pathological sonographic hip examinations. Measurement differences and the learning curve during the different courses were evaluated.

There was a significant (p = 0.001) improvement of the average angle between the basic (6.74 degrees [+/- 1.46 degrees ]) and the advanced course (6.22 degrees [+/- 1.17 degrees ]). However, there were no better results in the final course and no additional improvement. Participants had higher variations when measuring the beta-angle than the alpha-angle. A significant improvement was seen if the participants performed a large number of hip ultrasounds between the courses. Higher measurement differences were seen in pathological hip ultrasounds and in ultrasonographic examinations of poorer quality.

During the educational courses on hip ultrasound using the Graf method, a high intra- and interobserver variability was seen. These findings were most prominent in measurement of the beta-angle, in pathological hip ultrasounds and in ultrasonographic hip examinations of poorer quality. The best results were achieved by participants who had performed a large number of examinations between courses. For the improvement of ultrasonographic measurements, a large number of self-performed examinations and a training in potential mistakes seem to be of great importance.