Femoroacetabular Impingement (FAI)
Normally, the femoral head (ball) moves smoothly inside the acetabulum (socket). In femoroacetabular impingement, an abnormally shaped femur or acetabulum contact causing friction and limited motion.
The labrum is pinched during certain movements (impingement means, “to pinch”), and cartilage in the joint can be damaged. (illustration or picture here)
Femoroacetabular Impingement (FAI) may be a cause of early arthritis.
- There are two types of FAI: Cam and Pincer impingement
- -It’s possible to have a combination of both
Signs and Symptoms
- Pain and limited motion
- -especially with flexion and internal rotation of the hip
What causes femoroacetabular impingement (FAI)?
- Cam Impingement (illustration of cam impingement)
- -Excess bone forms making the femoral head (ball) asymmetrical
- Pincer Impingement (illustration of pincer impingement)
- -Excessive born formation or an abnormally shaped acetabulum (socket)
What damage is caused by femoroacetabular impingement (FAI)?
- Cam Impingement (arthroscopic picture of cam tear)
- -The labrum is pushed and progressively torn by the asymmetrical femural head during certain types of movement
- -Articular cartilage is damaged over time and can be sheared off the wall of the acetabulum
- Pincer Impingement (arthroscopic picture of pincer tear)
- -The labrum is pinched and torn between the acetabulum and femur during certain types of movement
Surgical Treatment: Hip Arthroscopy
- Osteoplasty is performed to correct the shape of the femur and/or acetabulum (video stream of decompression of both cam and pincer impingement)
- -excess bone is removed
- Secondary labral (see Labral Tears) and chondral injuries (see Chondral Defects) are repaired at the time of surgery