Hip

Femoroacetabular
Impingement

What is femoroacetabular impingement?

Femoroacetabular impingement (FAI)

is a condition in which the bones of the hip joint rub against each other abnormally, leading to pain, stiffness, and limited range of motion. The condition typically develops during adolescence or early adulthood and can affect both men and women. It seems to affect athletes and people with very active professions who have a high demand on their hip joints.

FAI is caused by an abnormal shape of the femoral head (ball) or acetabulum (socket) of the hip joint. In most cases, the femoral head is not perfectly round, or the acetabulum is too extensive, which causes the bones to rub against each other during movement.

There are three main types of FAI:

  1. Cam impingement: In this type of impingement, the femoral head is not perfectly round and has a bony protrusion that rubs against the acetabulum.
  2. Pincer impingement: In this type of impingement, the acetabulum is too deep or covers too much of the femoral head, causing the bones to rub against each other.
  3. Mixed impingement: This is a combination of cam and pincer impingement.

The symptoms and examination features of hip dysplasia and FAI can sometimes appear similar however it is very important to recognise the difference. FAI surgery performed for patients with hip dysplasia can accelerate changes and make symptoms worse, not better.

FAI symptoms can include pain in the hip or groin area, stiffness, and limited range of motion. The condition can also lead to cartilage damage and osteoarthritis if left untreated.

Treatment for FAI typically involves non-surgical options, such as physical therapy, activity modification, and pain management. In some cases, surgery may be necessary to correct the shape of the hip joint and prevent further damage. Surgical options may include hip arthroscopy or an open surgical procedure, such as a periacetabular osteotomy (PAO) or a femoral osteotomy. The specific treatment plan will depend on the severity of the condition and the age and activity level of the patient.