A review of femoroacetabular impingement in athletes.

There are a multitude of well recognized hip and groin injuries that commonly affect athletes; however, a more recently recognized and possibly often overlooked cause of hip pain is that of femoroacetabular impingement (FAI). FAI is characterized by abutment of the femoral neck against the acetabular rim, which may occur by two mechanisms known as 'CAM' or 'pincer' impingement, although most commonly by a mixture of both. CAM impingement is characterized by abutment of the femoral neck against the acetabulum due to a morphological abnormality of the femoral head-neck junction. Pincer impingement occurs where an abnormality of the acetabulum results in impingement against an often normal femoral neck. Both CAM and pincer impingement are known to result in pathological consequences of cartilage delamination and labral lesions, leading to significant pain and disruption to athletic performance and activities of daily living in athletes. There are currently several methods of assessing the degree of impingement by use of CT and magnetic resonance imaging scans, which can be used in conjunction with magnetic resonance arthrography and arthroscopy to assess the damage caused to the underlying structures of the hip. Both open and arthroscopic surgical methods are used, with recent reports in athletes showing excellent results for lifestyle improvement and frequency of returning to sport. In cases of hip and groin pain in athletes, it is important to remember to look for typical history, and examination and imaging findings that may suggest a diagnosis of hip impingement. This article goes some way to explaining the principles, consequences and management of FAI.