Assessment of variations in the measurement of hip ultrasonography by the Graf method in developmental dysplasia of the hip.

The purpose of this study was to assess the variations in the measurement of hip ultrasonography using the Graf method in developmental hip dysplasia. Twenty-two observers independently analyzed 20 hip ultrasonograms on two occasions. Intraobserver and interobserver agreement ratios on the exact Graf classification were 65% and 51%, respectively. Intraobserver and interobserver agreement ratios on the treatment method according to the hip type were 76% and 64%, respectively. Average intraobserver and interobserver differences were 4.0 degrees and 5.1 degrees for the alpha angle, and 5.9 degrees and 10.1 degrees for the beta angle, respectively. It was concluded that having a basic knowledge of the Graf method was the key point, and the observer's previous number of examinations had no effect on the results.