Hip Impingement

Femoroacetabular impingement (FAI) and labral tears are common causes of hip pain, particularly in athletes and young adults. These two conditions are often linked: the mechanical impingement eventually damages the protective structures of the joint.

1. What is Femoroacetabular Impingement (FAI)?

Normally, the hip functions like a ball joint (the femoral head) rotating perfectly within a socket (the acetabulum). In the case of FAI, a morphological abnormality of the bone causes abnormal contact ("bumping") during certain movements.

There are two main types of impingement:

• "CAM" effect: The femoral head is not perfectly round. It has a bony protrusion at the junction with the neck. During flexion, this bump forces its way into the socket.
• "Pincer" effect: The socket (acetabulum) is too deep or covers too much of the femoral head. It impacts the femoral neck like a pincer.

2. Labral Tears: The Direct Consequence

The labrum is a ring of fibrocartilage (similar to the meniscus in the knee) that surrounds the rim of the hip socket. It acts as a "seal" and stabilizes the joint.

When femoroacetabular impingement is present, the labrum gets "pinched" or crushed with every large-amplitude movement (flexion, internal rotation). With repeated stress, the labrum can:

• Become inflamed.
• Develop a tear.
• Detach from the bone (avulsion).

3. Symptoms and Warning Signs

Patients typically describe pain located in the groin crease, sometimes on the side of the hip or in the buttock.

• Groin pain: The patient places their hand in a C-shape over the hip to indicate the painful area.
• Pain with prolonged sitting: Typical of impingement that "pinches" during flexion.
• Locking or clicking: A sensation that something is catching inside the joint (often a sign of a labral tear).
• Pain during sports activities: Football, hockey, tennis, martial arts, or dance.

4. Treatments

1. Conservative treatment: Relative rest, modification of sports activities, anti-inflammatories, and especially physical therapy to strengthen the hip's stabilizing muscles.
2. Injections: Corticosteroid or hyaluronic acid injections to calm inflammation.
3. Surgery (Arthroscopy or Open surgery): If pain persists, surgery may be necessary to "shave down" excess bone (osteoplasty) and repair or reattach the damaged labrum.

Expert advice: Untreated femoroacetabular impingement can promote the early onset of hip osteoarthritis, as the cartilage eventually wears down due to repeated impacts.