What is femoroacetabular impingement (FAI)?
With FAI, certain activities can cause the ball and socket of the hip bump or impinge on each other, causing pain, inflammation, and sometimes a grinding or popping with hip movement. Frequently the ring of soft cartilage attached to the edge of the hip socket, called the labrum, is damaged or torn. The consequences of this is symptoms that limit activity and result in slow but progressive damage to the hip joint.
Types of FAI
FAI generally occurs in two forms: CAM and Pincer. At times both CAM and Pincer type impingement occur in the same hip, creating a mixed presentation.
The CAM for (CAM comes from the Dutch word meaning “cog”) describes a shape of the ball (femoral head) that is aspherical or not perfectly round. This loss of roundness of the femoral head contributes to a damaging, abnormal contact between the head and socket.
The Pincer type (Pincer comes from the French word meaning “to pinch”) describes the situation where the socket, or acetabulum, has too much coverage of the ball or femoral head. This over coverage typically exists along the front-top rim of the socket and results in the labral cartilage being “pinched” and damaged between the rim of the socket and the ball of the hip joint.
How is femoroacetabular impingement treated?
There are non-surgical options such as injections, medications, and physical therapy to address the modifiable variables contributing to FAI pain.
A minimally invasive arthoscopic surgery to reshape the bone contours of the ball and socket can be performed to treat FAI. Reshaping the joint reduces the interference causing the damage is relieved. Since tearing of the labral cartilage frequently accompanies this condition, a repair of the labrum is also commonly done. Hip arthroscopic surgery is highly successful in relieving pain and allowing patients—even athletes—to more quickly resume activities that previously had been too painful for them.