A new sign in the standard hip ultrasound image of the Graf method.

Abstract

Aim:    The aim of the study was to assess the usefulness of obtaining a 90⁰ angle between the plane of the osteochondral plate and the surface of the transducer during standard hip ultrasonography according to Graf method. Material and methods: In this retrospective study 1078 patients (2156 hips) were included examined between 2008 and 2014 for developmental dysplasia of the hip (DDH) ultrasound screening. The patients were divided in two groups. Group I consisted of 402 patients examined between January 2008 and December 2011 using the standard Graf method. Group II consisted of 676 patients examined from January 2012 to December 2014 using the Graf method with an additional criterion: 90⁰ angle between the plane of the osteochondral plate and the surface of the transducer. Results: We found more dysplastic patients in group I comparing to group II: 55 (13.7%) and 38 (5.6%) respectively. The difference in the incidence of patients diagnosed with DDH was highly significant (p<0.001). The mean alpha angle value in group I was 65.31⁰, respectively 67.52⁰ for group II (p<0.001). Conclusion: The new osteochondral plate sign has the potential to reduce the overdiagnosis of DDH and provide a better tailored approach to borderline hips.