The purpose of this poster is to review the normal anatomy, clinical presentation and pathogenesis of FAI; to emphasize the technical requirements and quality criteria for radiographic imaging technique; to describe the current radiographic findings for evaluation of FAI and to discuss the role of extra-articular anatomical factors such as femoral torsion, pelvic tilt and femoral neck angle in FAI.

FAI is increasingly recognized as a pathomechanical process that can lead to hip pain and early osteoarthritis of the hip in young and active adults. The hip joint is a ball-in-socket joint. The principle function of the hip is to enable weight bearing for locomotion. The normal anatomy of the hip joint consists of the following: the femoral head is slightly more than half a sphere; the femoral neck is cylindrical (narrowest in the midpoint and widest laterally) and attaches the head to the shaft;...

Standard conventional radiographic imaging in patients with FAI includes an anteroposterior pelvic view and an axial cross-table view of the proximal femur. If these radiographic projections are not correctly performed, the measurements cannot be correctly evaluated. For the anteroposterior pelvic radiograph, the patient is in the supine position with the legs 15º internally rotated. The central beam is directed to the midpoint between a line connecting both anterosuperior iliac spines and the superior border of the symphysis. The cross-table view of the proximal femur is...

FAI is a dynamic problem that can occur in patients with normal osseous anatomy that perform sports activities in which the hip is highly involved and in patients with underlying abnormal hip morphology, in which less motion is required before abutment between the femoral head and acetabular rim occurs. These signs must be tightly correlated to the clinical evaluation, as the diagnosis depends on both clinical and imaging findings. An early diagnosis is essential to initiate appropriate therapy in order to delay the onset of...

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