Developmental dysplasia of the hip (DDH) is a dynamic spectrum of hip joint abnormalities seen within the first year of life. It ranges from mild acetabular dysplasia to dislocation of the femoral head. Early diagnosis and treatment are important as the femoral head must articulate with the acetabulum for normal hip development to occur. Avascular necrosis of the femoral head is the main complication in inappropriately treated DDH1. Early detection rate of DDH is 8.4 infants per 1000 newborn, whereby more than 90% were identified via ultrasound examination2.
Ultrasound is performed via the Graf technique has a 100% sensitivity and 89.1% specificity. Although there some modifications or new methods such as modified Grad, Harcke technique, Terjesen technique, etc. Graf's technique remains the study of choice for evaluation.
Graf's technique is able to demonstrate the cartilaginous and soft tissue components of the hip joint, which are not visible on radiographs. However, the Graf technique can be technically challenging in bigger sized infants or when infant is struggling during the procedure. This is because poor resolution of image results in difficulty in identification of anatomical structures such as the acetabular roof and labrum, that are used for measurement.
In our proposed simplified Graf's technique, the anatomical structures required are not as stringent as in the Graf's technique. Thus, the purpose of this study is to evaluate the reliability of the simplified Graf technique, to see if measurements can still be diagnostic in challenging studies.