New developments in hip imaging.

The way the hip joint is imaged has changed in the past few years as a result of new discoveries in the biomechanics of the hip joint and the rapid developments in hip-preserving surgery. This review discusses technical advances made in the field of hip imaging, covering the roles of radiography, computed tomography, sonography and magnetic resonance (MR) imaging, as well as their limitations. New insight into anatomy and pathogenesis can be useful for the diagnosis of hip abnormalities and in treatment planning. While radiographs are the basis of any imaging of the hip, MR imaging is paramount in the evaluation and preoperative planning of patients suspected of having femoroacetabular impingement, especially when assessing geometrical deformities of the proximal femur. Damage patterns of labrum and cartilage in patients with femoroacetabular impingement are described, as well as new techniques of cartilage MR imaging that might allow the detection of cartilage degeneration before macroscopic defects are formed. Finally, new data on structural variants of the hip joint and pitfalls in imaging of the hip joint are reviewed. © RSNA, 2012