Femoraacetabular Impingement Syndrome (FAI)

Femoraacetabular Impingement Syndrome (FAI)

Hip impingement syndrome, medically known as femoroacetabular impingement (FAI), is a condition caused by abnormal contact between the femoral head and the hip socket (acetabulum) due to irregular bone shapes. In FAI, extra bone develops around the femoral head, the acetabulum, or both, leading to a misshapen joint structure.

This abnormality causes the bones to rub against each other during movement, which can result in hip pain, stiffness, and over time, damage to the cartilage and labrum. FAI is more common in athletes and physically active individuals, and if left untreated, it can lead to early-onset hip arthritis.

Early diagnosis and appropriate treatment are essential to protect the joint and prevent further deterioration. In this article, I’ll explain the causes, symptoms, diagnostic methods, and both non-surgical and surgical treatment options for FAI in detail.

What Is Femoroacetabular Impingement (FAI)?

 

The hip joint is formed by the acetabulum—a cup-shaped cavity in the pelvis—and the spherical femoral head at the top of the thigh bone (femur). These two structures are covered with smooth cartilage surfaces that allow low-friction movement within the joint. Thanks to the harmony between these structures, the hip joint offers a wide range of motion and supports everything from daily activities to high-level athletic performance.

Surrounding the acetabulum is the labrum, a strong and flexible ring of fibrocartilage. The labrum acts like a seal that helps maintain joint stability and holds the femoral head securely within the socket. It also preserves the joint fluid and plays a key role in stabilizing the hip.

Femoroacetabular impingement (FAI), or hip impingement syndrome, occurs when extra bone develops on the femoral neck, the edge of the acetabulum, or both. These bone overgrowths disrupt the natural contact between the joint surfaces and prevent the femoral head from moving freely and smoothly within the socket.

This abnormal contact can eventually lead to labral tears and cartilage wear. If left untreated, it may result in progressive joint damage and hip osteoarthritis over time.

FAI often presents more prominently in active individuals and athletes, but with early diagnosis and the right treatment approach, its progression can be halted and patients can significantly improve their quality of life.

For fast and lasting relief from hip impingement syndrome, contact Dr. Utku Erdem Özer. We are here to provide personalized solutions tailored to your needs.

Types of Hip Impingement Syndrome

Hip impingement syndrome, or femoroacetabular impingement (FAI), occurs due to abnormal contact between the femur and the acetabulum. It is typically classified into three types: Pincer type, Cam type, and Combined type, depending on where the excess bone growth occurs and how it affects joint function.

1. Pincer Type

In the pincer type of impingement, there is excessive bone growth at the rim of the acetabulum (hip socket). This overcoverage prevents the femoral head from moving smoothly within the joint.

• Effects: The bony overgrowth on the acetabulum causes repeated contact and pressure on the labrum, eventually leading to labral tears.

• Risk Factors: More commonly seen in women and tends to worsen with activities that involve frequent hip flexion.

2. Cam Type

In cam impingement, bone spurs form just below the femoral head, along the femoral neck. This alters the spherical shape of the femoral head, preventing it from rotating properly within the socket.

• Effects: The abnormal bone contour causes the femoral neck to scrape against the acetabular cartilage, which can result in labral tears and cartilage damage.

• Risk Factors: More common in men, especially those involved in high-impact or high-repetition sports.

3. Combined Type

This type involves features of both pincer and cam impingement. Abnormal bone growth occurs on both the acetabular rim and the femoral neck.

• Effects: The combination leads to more extensive and aggressive contact, resulting in faster and more widespread damage to the labrum and cartilage.

• Risk Factors: Because it includes characteristics of both types, it tends to be more complex and requires a comprehensive treatment approach.

All three types of FAI can be managed effectively with early diagnosis and appropriate treatment. However, if left untreated, they may lead to permanent joint damage and early-onset hip arthritis. In the following section, we’ll explore the underlying causes of hip impingement syndrome in more detail.

What Causes Hip Impingement Syndrome?

Femoroacetabular impingement (FAI) usually develops due to abnormal bone development during childhood or adolescence, as the hip joint forms. This irregular shaping leads to extra bone formation on the femoral head, neck, or the edge of the acetabulum.

FAI can be present in many individuals without causing symptoms. While some people never experience discomfort, others may develop hip pain, limited mobility, or structural joint damage over time.

Why Is It More Common in Athletes?

FAI is more likely to become symptomatic in athletes due to the repetitive and high-stress movements placed on the hip joint. Sports that involve frequent hip flexion, internal rotation, and adduction—such as football, dance, ice skating, or martial arts—can increase the pressure on the hip and make any existing impingement more noticeable.

Important Note: There is no scientific evidence suggesting that exercise or sports directly cause hip impingement. However, in individuals with anatomical abnormalities, physical activity can accelerate the onset and intensity of symptoms.

Genetic and Structural Factors

Some individuals may have a genetic predisposition to structural abnormalities in the hip joint. A family history of FAI or other hip conditions increases the risk of developing this syndrome.

Other Risk Factors Include:

• Engaging in high-level sports at a young age

• Repetitive movements that overload the hip joint

• Previous hip injuries or fractures

• Developmental disorders of the hip joint (e.g., hip dysplasia)

The causes of hip impingement syndrome can vary greatly from person to person. However, with early detection and appropriate treatment, long-term joint damage can often be prevented.

What Are the Symptoms of Hip Impingement Syndrome?

Femoroacetabular impingement (FAI) can present with a range of symptoms that may interfere with daily activities. The severity and frequency of symptoms vary depending on the person’s lifestyle, activity level, and the type of impingement.

1. Pain

• Pain is most commonly felt in the groin area.

• It may also radiate to the side of the groin or the back of the hip.

• Pain tends to increase after long walks, intense physical activity, or prolonged sitting (e.g., car or plane travel).

• Office workers may experience increased discomfort after long periods of inactivity.

2. Catching or Pinching Sensation

• Patients often describe a catching or pinching feeling at the front of the hip or groin.

• This sensation is usually more noticeable during hip flexion or rotation.

3. Limited Range of Motion

• Hip mobility may decrease, making daily movements more difficult.

• Tasks like putting on shoes or socks, bending over, or getting up from a low chair may become challenging.

• Athletes may notice a reduction in performance or difficulty performing specific movements during training.

4. Mechanical Symptoms

• Clicking, popping, or snapping sounds may be heard from the hip joint.

• Some patients report a sense of instability in the hip.

FAI symptoms may be mild and temporary in the early stages but can become more persistent and severe over time. Recognizing these symptoms early and consulting an orthopedic specialist is crucial to prevent long-term joint damage.

How Is Hip Impingement Syndrome Diagnosed?

Accurate and early diagnosis of femoroacetabular impingement (FAI) is essential for preventing joint damage and planning the appropriate treatment. Diagnosis is based on the patient’s medical history, a physical examination, and advanced imaging techniques.

1. Patient History and Symptoms

• The location, duration, and triggers of hip pain are assessed.

• The patient’s daily activities, occupation, and sports background are reviewed.

• Symptoms such as pain, catching sensations, and limited mobility are discussed.

2. Physical Examination

• The hip joint’s range of motion is evaluated, and movements that provoke pain are identified.

• Pain during hip flexion, internal rotation, or external rotation is a key diagnostic clue.

3. Imaging Techniques

• X-Ray:

  • Often the first step in evaluation.

  • Reveals bone spurs, joint space narrowing, or abnormal bone structures in the hip.

• CT Scan:

  • Provides a more detailed view of bony overgrowths, including their size, location, and shape.

  • Helps assess structural mismatches and areas of impingement.

• MRI:

  • Evaluates the condition of cartilage and detects labral tears.

  • Also helps assess joint fluid and other soft tissue damage.

4. Definitive Diagnosis

The final diagnosis is made by combining the patient’s clinical history, physical exam findings, and imaging results.Early diagnosis plays a critical role in preventing irreversible joint damage and preserving quality of life.

How Is Hip Impingement Syndrome Treated?

Treatment for femoroacetabular impingement (FAI) depends on the patient’s symptoms, the impact on daily activities, and the severity of the structural problem. The treatment process begins with non-surgical approaches and, if necessary, progresses to surgical intervention.

Non-Surgical Treatment for Hip Impingement Syndrome

The initial step in managing FAI is modifying the patient’s lifestyle and activity levels:

• Activity Modification:Avoid movements that provoke pain and reduce stress on the hip joint.

• Physical Therapy:Focuses on improving hip mobility and strengthening the muscles that support the joint, particularly:

  • Gluteus Medius and Minimus: Enhance hip stability.

  • Gluteus Maximus: Plays a key role in hip extension and posture.

  • Core Muscles: Support trunk stability and reduce load on the hip.

• Pain Management: If needed, pain relievers and anti-inflammatory medications may be used.

These non-surgical strategies can be highly effective in early-stage cases by reducing symptoms and improving quality of life. However, if symptoms persist despite conservative treatment, surgical intervention may be considered.

Hip Impingement Surgery

If non-surgical treatments fail to provide sufficient relief and the patient continues to experience pain, limited mobility, or significantly reduced athletic performance, surgical intervention is considered.

How Is Hip Impingement Surgery Performed?

Most cases of femoroacetabular impingement (FAI) are treated using minimally invasive arthroscopic surgery.

• Arthroscopic Surgery: Hip arthroscopy is different from other joint arthroscopies and requires specialized instruments and techniques. Because the hip joint is naturally tight, a special surgical table is used to gently distract the joint space and allow safe access and visibility.

• Small Incisions: Typically, 3 to 4 small incisions of about 1.5 cm are made.

• Camera Insertion: A small camera is inserted through one incision to visualize the inside of the joint.

• Specialized Instruments: Through the other incisions, surgical tools are used to trim and reshape bone spurs.

• Intraoperative Imaging (Fluoroscopy): A mobile X-ray machine (fluoroscopy) helps ensure accuracy during the procedure.

Labrum Repair:

• Repairable Tears:The labrum is sutured and preserved.

• Irreparable Tears:In cases of extensive damage, the torn labrum may be removed and reconstructed.

Arthroscopic hip surgery is less invasive, which leads to a quicker recovery and a lower risk of complications.

Recovery After Hip Impingement Surgery

Postoperative care plays a crucial role in the success of treatment:

• Incision Healing:Incisions usually heal within one week.

• Physical Therapy:Begins immediately after surgery to restore range of motion and strengthen the surrounding muscles.

• Weight Bearing:

  • If no labral repair is performed, patients may start partial weight bearing with crutches immediately.

  • If the labrum is repaired, full weight bearing may be delayed for a few weeks.

• Return to Daily Activities: Most patients resume everyday activities within about a month.

• Return to Sports:Athletes generally return to full sports activity within 3–4 months.

Adherence to physical therapy and regular follow-up visits are essential for optimal recovery.

Frequently Asked Questions (FAQ)

1. Can hip impingement go away on its own?

No, hip impingement typically does not resolve spontaneously. However, early intervention and lifestyle changes can help manage symptoms and prevent progression.

2. Can FAI be treated without surgery?

Yes, in the early stages, non-surgical treatments such as activity modification, physical therapy, and pain management can be effective. Surgery may be necessary for advanced cases.

3. How long is the recovery after surgery?Incisions usually heal in about a week. Most patients return to daily activities in a month and to sports in 3–4 months.

4. Does FAI prevent participation in sports?

Not necessarily. With proper treatment, many patients return to sports. Untreated FAI, however, may lead to pain and reduced performance.

5. Is hip impingement surgery risky?

Hip arthroscopy is generally safe when performed by an experienced surgeon. As with any surgery, risks such as infection, nerve injury, or joint stiffness exist but are rare.

6. Is physical therapy necessary after surgery?

Yes. Physical therapy is vital for restoring motion, rebuilding strength, and ensuring a smooth recovery.

7. Can FAI lead to hip arthritis?

Yes. If left untreated, FAI can damage cartilage over time and increase the risk of developing hip osteoarthritis.

8. Which sports can trigger FAI symptoms?

Sports involving frequent hip flexion and rotation—like football, basketball, dance, ice skating, martial arts, and yoga—can aggravate FAI symptoms.

9. Who is most at risk of developing hip impingement?

FAI is more common in athletes, physically active individuals, and those with congenital hip structure abnormalities.

10. Can FAI be prevented?

While not entirely preventable, you can reduce your risk by:

• Exercising regularly with proper technique

• Avoiding overuse

• Strengthening the muscles around the hip joint

Conclusion

Femoroacetabular impingement (FAI) is a condition that, if left untreated, can lead to serious damage within the hip joint and significantly impair quality of life. With early diagnosis and appropriate treatment, pain can be managed, mobility restored, and progressive cartilage damage prevented.

While non-surgical methods are effective for many patients, arthroscopic surgery offers a reliable and minimally invasive solution for advanced cases. Postoperative physical therapy and regular monitoring are critical for a successful outcome.

Remember: hip joint health is key to maintaining your freedom of movement.

Experiencing hip pain, stiffness, or a catching sensation? Don’t wait. Dr. Utku Erdem Özer is here to help with expert orthopedic care. Take the first step toward a healthier, more active life—starting today.