The hip joint is made from the connection of the top, ball shaped, end of the thighbone (femur) and the socket of the pelvis (acetabulum), which allows for motion in nearly all directions. In hip impingement, or FAI, the structure of the hip is subtly altered, resulting in abnormal motion. The ball and socket of the hip do not quite fit together properly, resulting in abnormal mechanics and eventual damage to the joint. Long-standing, untreated FAI may actually be one of the most common causes of osteoarthritis of the hip.
There are two types of hip impingement:
• Cam impingement occurs when the ball of the hip joint is not perfectly round.
• Pincer impingement occurs when the socket of the hip overhangs and impinges (presses) against the ball.
In both cases this can lead to labral tears, cartilage damage and hip pain.
Learn more about Femoroacetabular Impingement (FAI)