Femoro-acetabular Impingement(FAI) Symptoms & Treatment

Overview

The hip is commonly referred to as a ball-and-socket joint. The ball, located at the top of the femur (thigh bone), fits into the acetabulum, a socket in the pelvic bone. Surrounding the edge of the socket is the hip labrum, a strong ring of cartilage that deepens the socket, stabilizes the joint, and provides cushioning during movement.

In femoro-acetabular impingement, abnormal bone development—either from birth (congenital) or due to early joint degeneration—causes extra bone to form along the femur, the acetabulum, or both. This bony overgrowth restricts smooth motion and creates repeated friction within the joint. Over time, this abnormal contact frequently leads to a hip labral tear and damage to the cartilage lining the joint surfaces.

Types of Femoro-Acetabular Impingement

There are three recognized types of femoroacetabular impingement:

Pincer Impingement

Pincer impingement occurs when extra bone forms along the rim of the hip socket, causing excessive coverage of the hip joint. As the hip moves, this overcoverage pinches the labrum, which can lead to groin pain, stiffness, and a clicking or catching sensation in the hip.

Cam Impingement

Cam impingement occurs when the femoral head is not perfectly round. Because of this abnormal shape, the femur cannot rotate smoothly inside the socket, leading to cartilage damage and labral tearing.

Combined Impingement

This is the most common type and involves both cam and pincer deformities. Patients with combined FAI often experience more severe symptoms and a higher risk of progressive joint damage.

 

What causes Femoro-acetabular Impingement(FAI)?

Femoroacetabular impingement (FAI) occurs when the bones of the hip joint are abnormally shaped and rub against each other during movement. This altered bone shape typically develops as the hip grows, but symptoms often do not appear until later, especially with increased activity or repetitive motion.

1. How the Injury Occurs

Abnormal hip bone shapes can cause the joint surfaces to repeatedly bump into each other. Frequent bending and twisting of the hip increases this contact over time, leading to irritation within the joint. As the friction continues, the labrum may become damaged, resulting in pain, stiffness, and labral tears.

2. Common Everyday Causes

• Prolonged sitting with the hips bent
• Repetitive bending, squatting, or climbing stairs
• Poor movement mechanics during daily activities

Sports Commonly Associated with FAI

FAI is frequently seen in athletes participating in sports that require repetitive hip motion and rotation, including:

• Soccer
• Tennis
• Lacrosse
• Hockey
• Football
• Squash
• Martial arts
• Gymnastics

These sports increase stress on the hip joint, making hip labrum tear symptoms more likely to develop.

Symptoms

Symptoms may develop gradually and worsen over time. While groin pain is most common, discomfort may spread throughout the hip.

Common Symptoms Include:

• Groin or deep hip pain, especially during activity
• Limping due to discomfort or stiffness
• Pain with hip bending combined with inward rotation
• Stiffness and reduced range of motion
• Clicking, catching, or locking sensations in the hip

These are classic hip labral tear symptoms, particularly when labral damage has already occurred.

Non-operative treatment

Initial FAI  treatment is usually non-surgical and focuses on symptom relief and improved movement.

Common non-operative options include:

• Rest and activity modification
• Ice to reduce inflammation
• NSAIDs such as ibuprofen or aspirin
• Physical therapy
• Cortisone injections to reduce pain and inflammation

Physical Therapy and Exercises

Hip labrum tear exercises focus on:

• Improving hip mobility
• Strengthening surrounding muscles
• Reducing stress on the hip joint

Targeted exercises are essential for improving function and preventing symptom progression.

Surgical Treatment

Surgery may be recommended if non-operative treatment fails and symptoms persist.

Arthroscopic Surgery

Minimally invasive arthroscopy is commonly used to:

• Remove bony overgrowth
• Repair or trim the torn hip labrum
• Smooth damaged joint cartilage

These procedures are often performed as outpatient surgery.

Open Surgery

In severe cases where deformities are extensive, open surgery may be required to adequately correct the impingement.

Total Hip Replacement

If FAI has led to advanced arthritis and severe cartilage loss, hip replacement may be discussed as a final treatment option.