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Femoroacetabular impingement: the past, current controversies and future perspectives.

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Nakano, Naoki 


Femoroacetabular impingement (FAI) is a clinical syndrome in which the anatomical abnormalities of the femoral ead and/or the acetabulum result in abnormal contact between the femur and acetabulum during normal hip motion, leading to cartilage and/or labral damage and hip pain. It is often subdivided into cam-type and pincer-type impingement, which results from a reduction in femoral head-neck offset (cam) or over-coverage or focal/global acetabular retroversion (pincer). There is also mixed-type FAI in which both cam- and pincer-type deformities develop in the same hip. FAI has been considered a precursor to secondary osteoarthritis (OA) especially in cam-type impingement, but there is still no conclusive evidence about pincer-type impingement leading to OA.[1] In the United States, FAI surgery rate increased seven-fold among newly trained orthopaedic surgeons between 2006 and 2010, and this is projected to increase further.[2] The number of FAI-related publications increased five-fold between 2005 and 2010, showing a recent boom in FAI-related research.[3] Despite the large increase in the number of hip arthroscopies performed on FAI patients, the optimal diagnostic approach and treatment of FAI remains uncertain and controversial.



Hip, arthroscopy, femoroacetabular impingement, sports medicine

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Phys Sportsmed

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Informa UK Limited