Imaging the hip

• Age is an important determinant in the aetiology of hip disorders. • MRI is the key imaging technique in a variety of conditions involving the bone, including occult fracture, stress fracture, avascular necrosis and transient osteoporosis. • Synovial diseases are well characterized on MRI, including pigmented villonodular synovitis, synovial osteochondromatosis and inflammatory arthropathies. • MR arthrography allows assessment of intra-articular pathology, including tears of the acetabular labrum. • CT provides detailed information on bone morphology and may provide a definitive diagnosis of osteoid osteoma. • Ultrasound may be used to evaluate bursitis, joint effusions and snapping hips, as well as guiding injections. In this article, we review the clinical presentation and imaging appearances of a wide spectrum of disorders of the hip. The role of different imaging modalities is highlighted for each condition.