[Femoroacetabular impingement: a new direction in the diagnosis and treatment of the hip joint].

Femoroacetabular impingement is a relatively recently described condition in which an abnormally shaped proximal part of the femur or acetabular overcoverage causes interference between the femoral head-neck junction and the acetabular rim. These disorders are now recognized as common causes of prearthritic hip pain and secondary osteoarthritis. Two mechanisms have been described. Cam-type impingement is caused by insufficient concavity of the femoral head-neck junction. Pincer-type impingement is caused by overcoverage of the femoral head by the acetabulum. Abnormal femoroacetabular abutment predisposes affected patients to labral tears, articular cartilage damage, and premature osteoarthritis. Early diagnosis of hip disease and referral for specialized care may optimize clinical outcomes and alter the natural history of these disorders. This review aims to describe this syndrome and to review the contemporary concepts of the etiology and surgical treatment of the disorder.