This is a relatively new concept in orthopaedics. The hip joint is a ball and socket joint. Femoroacetabular impingement (FAI) occurs when the edges of the ball and socket rub together. This can be due to extremes of movement, such as in ballet dancers, developmental hip disorders, and cam lesions.
Cam lesions, or “femoral neck bumps”, are abnormal growths of bone which make the ball part of the hip joint “out of round” with the socket. The bumps of bone rub on the edge and in the socket damaging the labrum and the lining of the socket.
FAI can be treated by open operations or by minimally invasive arthroscopic surgery.