RADIOGRAPHIC MEASUREMENTS OF DYSPLASTIC ADULT HIPS

Hip dysplasia is a not uncommon feature in adults and can vary from su btle acetabular dysplasia to complex sequelae of developmental dysplas ia of the hip. This review article describes the most useful radiograp hic measurements used to evaluate the adult hip. The frontal projectio n of the pelvis permits measurement of the center-edge angle (CE angle ) and ''horizontal toit externe'' angle (HTE angle), both of which ass ess the superior coverage of the acetabulum. The femoral neck-shaft an gle (NSA) is also measured on this view, The false profile radiograph of the pelvis is described. It allows measurement of the vertical-cent er-anterior angle (VCA angle), which determines the anterior acetabula r coverage and detects early degenerative hip joint disease. When surg ery is contemplated, computed tomography (CT) is useful to better dete rmine the anterior acetabular coverage by use of the anterior acetabul ar sector angle (AASA), and the posterior acetabular coverage by use o f the posterior acetabular sector angle (PASA). CT also permits measur ement of femoral anteversion. These measurements are particularly usef ul in the evaluation of acetabular dysplasia and for the preoperative assessment of the dysplastic hip.