Femoroacetabular Impingement of the Hip

Femoroacetabular impingement (FAI) is a condition where the two bones of the hip are abnormally shaped, hence do not fit together properly, causing the two bones to rub against each other and cause damage to the joint.

The hip is a ball and socket joint. The socket is called the acetabulum and is part of the pelvis and the ball is the femoral head, which is the upper end of the femur (thigh bone). There is articular cartilage that lines the surface of the ball and socket, which creates a smooth surface for the bones to glide across each other. There is also a strong rim of fibrocartilage called the labrum that lines the acetabulum to help create a seal and provide stability for the joint.

FAI is where bone spurs develop around the femoral head and/or the acetabulum , causing the bones to hit against each other. Over time this can result in wearing the cartilage down and tearing the labrum, and in the long run may cause osteoarthritis (OA).

FAI is caused by hip bones not forming normally in childhood growing years. Symptoms normally include pain, stiffness and limping. Pain may be sharp stabbing pain or a dull ache in the groin area or the outside of the hip. Pain is often reported with twisting and turning and squatting.

Xrays will confirm if you have abnormally shaped bones of FAI, and can also show signs of OA. MRI may be useful to determine damage to the labrum and cartilage.

Non surgical treatment of FAI may involve 1) non – steroidal anti-inflammatory medication 2) activity changes to avoid causing impingement of the hip, and 3) physiotherapy to help improve the range of motion in your hip and strengthen the muscles that support the joint. This will help take the stress off the injured labrum or cartilage. If the FAI is not relieved from conservative methods, then surgery can be considered where they clean up or repair the damage to the labrum or cartilage, and shave off the spurs on the bones.