Femoroacetabular Impingement Treatment

Femoroacetabular Impingement

Femoroacetabular Impingement (FAI) is a condition that is thought to be present in 30% of people according to a study by Wall, et al. It refers to an impingement of the hip joint. The hip joint is a ball-in-socket joint with the head of the femur being equivalent to a ball inside the socket of the acetabulum. Another important structure is the labrum, which provides extra support to the acetabulum and more stability for the femur. The labrum is not bone, rather it is made up of cartilage. The hip joint is deeper and a more secure socket than the shoulder joint, which is why we have less hip range of motion compared to the shoulder.

The hip does require significant mobility in multiple directions, which requires the femur to glide smoothly in the acetabulum. Unfortunately, there can be cases where either the acetabulum or the femur have bony overgrowths as shown in the image below

Takuma-sa, de: Hellerhoff, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons

The first image shows a normal hip with the femur and acetabulum remaining congruent and some support from the labrum. The second image demonstrates a cam impingement, which occurs when there is bony growth on the femur. The third image is a pincer impingement, which is when the bone grows on the acetabulum. Both are not ideal because if you imagine the femur rolling in the acetabulum, it will run into the bony overgrowth which prevents movement.