Femoral Acetabular Impingement Syndrome

Hip impingement syndrome, also known as femoral acetabular impingement syndrome (FAIS), is a recently accepted condition that usually affects young and middle-aged adults. Pain is caused because two areas are contacting or impinging on each other resulting in pain. The femoral head rotates in the socket (acetabulum). During impingement, the neck of the femur contacts the lip of the hip socket.

It is characterized by hip pain felt mainly in the groin and can result in chronic pain and decreased range of motion. FAIS has been reported to be associated with progressive osteoarthritis of the hip.

Activities that cause problems with hip impingement are those that involve hip flexion, such as: sitting in a car, squatting, and bending during various athletic exercises. Pain can be minimal with straight and level walking.

The two basic mechanisms of FAI are cam impingement (most common in young athletic males) and pincer impingement (most common in middle-aged women).

Femoroacetabular impingement or FAI is a condition of too much friction in the hip joint. Basically, the ball (femoral head) and socket (acetabulum) rub abnormally creating damage to the hip joint. This causes pain and eventual loss of motion of the hip. The damage can occur to the articular cartilage (smooth white surface of the ball or socket) or the labral cartilage (soft tissue bumper of the socket).

FAI is associated with cartilage damage, labral tears, early hip arthritis, hyperlaxity, sports hernias, and low back pain.
FAI is common in high level athletes, but also occurs in active individuals.