Imaging of impingement syndromes around the hip joint.

Impingement syndromes are increasingly recognised as significant causes of hip pain and dysfunction. A broad spectrum of intraarticular and extraarticular conditions has been implicated in their pathophysiology. Physical examination is often inconclusive as clinical findings may be unclear or misleading, often simulating other disorders. With current improvements in imaging techniques and better understanding of hip impingement related pathomechanisms, these entities can be accurately diagnosed. In addition, preoperative imaging has allowed for targeted treatment planning. This article provides an overview of the various types of hip impingement, including femoroacetabular impingement, ischiofemoral impingement, snapping hip syndrome, greater trochanteric-pelvic and subspine impingement. Current literature data regarding their pathogenesis, clinical manifestation and imaging work-up are discussed.