Aim: Inter- and intraobserver reliability and learning curve using Graf's ultrasonographic hip examination were assessed.
Material and methods: 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.
Results: 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.
Conclusions: 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.