Femoroacetabular Impingement (FAI)
Hip Anatomy
The normal hip is a congruent ball and socket joint. The femoral head (ball) rotates on the acetabulum (socket) to achieve a full hip range of motion.
Cartilage lines the ball and the socket to reduce friction between the bones. The labrum cushions the joint and acts like a rubber seal or gasket to help hold the ball securely within the socket.
What is Femoroacetabular Impingement?
FAI occurs when there is a mismatch between the ball (femur) and the socket (acetabulum). Impingement (abnormal contact) occurs when this mismatch within the hip joint leads to cartilage and labrum damage. Damage to cartilage and the labrum leads to pain, decreased function, and increased risk of progression to arthritis.
Click on a hip condition below to see the repair.
Symptoms of FAI
People who suffer from FAI are usually active individuals between the ages of 15 to 55. Females have a greater risk of FAI than males. Patients who experience FAI describe the following symptoms:
- Pain in the groin, buttock, and/or lateral side of the hip
- Pain with running, squatting, prolonged sitting, etc
- Decreased range of motion
- Decreased strength or endurance
Types of FAI
Cam Impingement
- The femoral head (ball) is not completely round
- The non-round ball rotates into the round socket which may lead to cartilage damage and labral tearing
Pincer Impingement
- The acetabulum (socket) is too deep or facing backward (retroverted) which prevents the ball from clearing the socket during hip movement
- Damage occurs when the femur collides into the overhanging rim of the socket which may lead to labral tearing
Mixed or Combined: Elements of both cam and pincer
FAI Treatment
Not all patients with FAI on x-ray will become symptomatic and require treatment. Many people with FAI have similar x-ray findings on the other hip but do not have symptoms. The goal of treatment is to decrease pain and increase function by reducing inflammation and optimizing hip and pelvis mechanics.
Non-operative Treatments for FAI
Non-operative treatment for patients with FAI is often successful and can avoid the need for surgery.
- Rest and avoiding painful activities alone may improve symptoms
- Anti-inflammatory medicines (Advil, Aleve, etc.) and cortisone injections can decrease pain and inflammation
- Physical therapy is essential for improvement in hip and pelvis mechanics and mobility
Hip Arthroscopy for Treatment of FAI
Hip arthroscopy, also referred to as "keyhole" or minimally invasive surgery, is typically necessary for cases that do not improve with conservative treatment. The goal of hip arthroscopy is to correct the bony abnormality causing impingement and repair the damage to the labrum and cartilage. Traction is used to increase space within the joint. Three (3) poke-hole incisions are made to place a small video camera and specialized instruments into the hip joint.
Patients return home the same day after surgery. Patients are on crutches for 3-4 weeks. Full recovery takes 5 to 6 months and requires physical therapy to restore optimal hip function. About 1 in 3 patients eventually undergo hip arthroscopy on the other side. Hip arthroscopy is not effective in patients with arthritis or severe dysplasia.