FAI and Hip Impingement

FAI occurs when the shape of the femoral head and neck (ball) does not match the acetabulum (socket). This can occur due to deformity of the head/neck, the acetabulum, or a combination of the two.

Cam impingement refers to impingement emanating from the head/neck junction due to the shape of the junction not being round. It is commonly oval with decreased offset and oftentimes has a bump along the head/neck junction. The “oval” shape does not match the round shape of the socket. As a result, as a patient flexes his/her hip, the head/neck junction contacts the rim of the socket rather than rolls under the socket due to the mismatch. As this repetitively occurs with chronic impingement, the labrum tears followed by damage to the articular cartilage. At the time of surgery the entire process is addressed. The labral tear is repaired and the impingement is removed, making the hip a normal shape and protecting against further damage.

Radiographic example of the cam lesion pre and post removal (Left picture); the hip is now a normal shape (Right picture).

Pincer impingement refers to impingement emanating from the acetabulum or socket. In this scenario a portion of the socket or the entire socket is too deep or overhangs too much. As a result, when the patient flexes the hip the overhanging socket contacts the femoral head/neck region. Similar to cam impingement, as this repetitively occurs, the labrum tears followed by damage to the articular cartilage. At the time of surgery, the labral tear is repaired and the impingement is addressed, making the hip a normal shape and protecting against further damage.

Arthroscopic example of Pincer Impingement (Left picture); the bump behind the labrum is in the process of resection at the time of surgery (Right picture).

Combined impingement refers to patients that have both issues. Most patients have a combination pattern with one predominating. Males tend to have more cam lesions and females tend to have more pincer lesions.

Surgical treatment of femoroacetabular impingement is predominantly arthroscopic with repair of the labrum and re-shaping of the ball and/or socket in order to make it a normal shape by removing the impingement. The results are largely good to excellent with patients and athletes returning to their activities with minimal to no discomfort.

Pincer Impingement Taken Down First (Left picture); Following burring down of the “bump” (Right picture).

Cam Lesion Being Taken Down; 2 Different Cases Shown Here

Labral tear being repaired (Left picture); Following Repair (Right Picture)