What Is Femoroacetabular Impingement (FAI)?

Femoroacetabular impingement syndrome occurs when the hip bones do not fit together perfectly due to an abnormal shape. This improper alignment causes the bones to rub against each other during movement, which leads to repeated friction. Over time, this friction may cause severe hip pain, cartilage damage, and a potential labral tear.

At Total Orthopedics and Sports Medicine, our fellowship-trained surgeon, Dr. Charles Ruotolo, first recommends non-operative management for FAI through activity modification, targeted exercises, and anti-inflammatory medications. If these treatment options fail to relieve your symptoms, he performs FAI surgery, such as hip arthroscopy, to reshape the excess bone and repair any torn cartilage or labrum. Contact us now to consult Dr. Charles Ruotolo at our Deer Park clinic.

What Are the Causes of Femoroacetabular Impingement?

High-impact athletic training, family history, and pediatric hip disorders, such as SCFE, can cause femoroacetabular impingement. Other than that, past hip trauma or repeated extreme hip flexion during deep squats, martial arts, and gymnastics can also contribute to FAI.

In many cases, biomechanical issues, such as poor posture, uneven leg length, or misalignment of the spine and pelvis, further increase the risk of this hip disorder. Similarly, Caucasians have specific hip anatomy that may cause impingement.

Here’s how these conditions can cause femoroacetabular impingement:

High-Impact Athletic Training

During high-impact athletic training, individuals perform repetitive movements like heavy deep squats, lunges, sprinting, and pivoting. These movements can force the thigh bone to repeatedly rub against the edge of the hip socket. As this rubbing increases, extra bone may develop on the femur ball or the rim of the hip socket. According to the Pediatric Rheumatology Journal, the risk of FAI increases further in young athletic males because their growth plates, or physes, are still developing and may deform more easily.

Family History

Although a family history of FAI does not always mean you will develop the condition, it can still increase the risk of abnormal bone shape. In fact, according to the Journal of Hip Preservation Surgery, siblings of patients with FAI have a three-times higher risk of developing hip impingement compared with people without a genetic predisposition.

Pediatric Hip Disorders

Several pediatric hip disorders can change the normal shape and alignment of the hip joint during growth. As a result, the femoral head and hip socket may not develop properly. This abnormal development can increase the risk of femoroacetabular impingement syndrome later in life. Here are some common pediatric conditions that contribute to FAI:

• Slipped Capital Femoral Epiphysis (SCFE) occurs when the ball of the hip joint slips backward from the top of the femur bone through the growth plate. This shift can result in a cam deformity.
• Legg-Calvé-Perthes Disease develops when the blood supply to the femoral head gets temporarily disrupted. As a result, the bone can weaken, collapse, and heal with an irregular shape.
• Developmental Hip Dysplasia occurs when the hip socket doesn’t cover the femoral head. Because the joint lacks normal coverage, abnormal stress is placed on the hip, which alters its shape.

Extreme Hip Flexion

Extreme hip flexion above 75 to 120 degrees, especially when combined with internal rotation or adduction, can force the thigh bone and hip socket to collide rather than move smoothly. As this abnormal contact occurs repeatedly, it increases the risk of FAI by placing excessive stress on the joint surfaces. In addition, it can compress the soft tissue (labrum) that surrounds the hip socket and absorbs shock, potentially leading to a labral tear.

Biomechanical Issues

Biomechanical issues can increase the risk of femoroacetabular impingement by changing the alignment and loading of the hip joint. Some common biomechanical issues that may contribute to FAI include:

• Poor posture tilts the pelvis and disrupts normal hip mechanics during walking, bending, or sitting. As a result, the ball of the thigh bone may rub against the hip socket and worsen FAI symptoms.
• Uneven leg length can shift body weight toward one hip. Over time, this uneven loading may increase joint stress and contribute to hip impingement.
• Weak glute muscles reduce hip stability and limit proper hip extension during movement. In such cases, the thigh rotates inward and places the femoral head (thigh bone ball) in a pinched position.
• Dynamic hip adduction occurs when the hip collapses inward during squats, running, or jumping. This movement can increase friction between the femoral neck and the hip socket.

What Are the Different Types of FAI?

FAI is classified into three major types: cam, pincer, or combined impingement, depending on the location of the abnormal bone growth. In cam impingement, the ball of the hip joint develops an extra bony bump that prevents smooth movement within the socket. As a result, the abnormal bone can grind against the articular cartilage and damage the joint over time.

In pincer impingement, extra bone grows along the rim of the acetabulum (hip socket), causing excessive coverage of the ball of the hip joint. In such cases, the labrum can be pinched or compressed during movement, which leads to groin pain, inflammation, cartilage damage, and an increased risk of labral tears. According to a PubMed Central study, cam lesions are more common in young males, whereas pincer impingement affects middle-aged athletic women.

What If You Have Both Types of Impingement?

If you have both types of impingement, known as combined FAI, your hip joint may experience too much friction. This happens because both parts of the joint contribute to abnormal contact during movement. In such cases, you may experience sharp, stabbing pain in the groin or the front of the hip. You may also notice clicking, catching, and locking sensations, along with a reduced range of motion. Over time, combined FAI can increase the risk of early osteoarthritis due to severe cartilage damage and labral tears.

What Does Hip Impingement Feel Like?

If you have hip impingement, you may experience a constant dull ache in the front of the hip and groin area. This pain often radiates into the buttocks, thighs, or knees. It also worsens during specific movements, such as bringing your knee toward your chest, squatting deeply, or twisting your leg inward.

Here are some other symptoms of hip impingement:

• Hip stiffness, especially after prolonged sitting
• Clicking, popping, or snapping sensations in the hip
• Catching sensations during movement
• Locking of the hip joint
• Reduced range of motion
• Weakness or instability during certain movements
• Difficulty pivoting, cutting, or changing direction
• Pain during running or jumping activities
• Balance and coordination problems
• Limping during symptom flare-ups
• Feeling that the hip gets “stuck” during movement

Why Does Hip Pain Feel Worse When Sitting?

The seated position forces the hip joint into 90-degree flexion, which may pinch abnormal bone structures and cause worsening pain. At the same time, soft tissues such as the labrum may be compressed between the bones, further increasing pain, stiffness, and pinching sensations.

Here are some ways to minimize pain while sitting:

• Use a chair that keeps your hips slightly above your knees
• Stand up and stretch every 30 to 60 minutes
• Avoid crossing your legs while sitting
• Use a small lumbar support cushion
• Take short walking breaks throughout the day
• Perform gentle hip mobility exercises as recommended by your doctor

How Do Doctors Diagnose Hip Impingement?

To diagnose hip impingement, our top hip surgeon, Dr. Charles Ruotolo, performs a thorough clinical assessment, specialized hip range-of-motion tests, and diagnostic imaging. He first reviews your symptoms, trigger activities, sports history, and family medical history. Then he performs the FADIR physical examination to assess pain, hip range of motion, and movement restrictions.

During the FADIR physical exam, you lie on your back while the doctor lifts your leg toward your chest. Then, he moves the leg across the body and rotates the knee inward. If this movement causes groin pain or a pinching sensation, it may strongly indicate hip impingement.

In addition, Dr. Charles Ruotolo may analyze the following imaging tests for proper diagnosis of hip impingement:

• X-rays show abnormal bone shape, cam lesions, pincer overcoverage, bone spurs, and early signs of hip osteoarthritis.
• Magnetic Resonance Imaging (MRI) scans reveal labral tears, cartilage damage, inflammation, and soft-tissue irritation around the hip joint.
• CT scans help identify the exact size and location of cam and pincer impingement through detailed 3D images of the hip joint. Surgeons also use these scans to plan minimally invasive surgery.

Can Untreated FAI Cause Other Problems?

Yes, untreated FAI can cause secondary orthopedic problems. For example, repeated friction within the hip joint can gradually damage the cartilage. As the cartilage wears away, the bones lose their protective cushioning and begin to rub against each other more directly, which may contribute to early hip osteoarthritis.

Similarly, repeated abnormal contact between the bones can strain and tear the labrum. In fact, a systematic review on ResearchGate found that almost 93.8% of femoroacetabular impingement cases involved labral tears. In many cases, altered hip mechanics and continuous abnormal loading can place excessive stress on surrounding structures. This excessive strain can lead to the following secondary conditions:

• Hip flexor tendinitis
• Gluteal tendinopathy
• Trochanteric bursitis
• Sacroiliac (SI) joint dysfunction
• Muscle imbalances around the hip and pelvis

How Is Femoroacetabular Impingement Treated?

Our sports medicine expert, Dr. Charles Ruotolo, initially treats femoroacetabular impingement with conservative care, including targeted exercises, activity modification, corticosteroid injections, and anti-inflammatory medications. He usually recommends these treatment options for at least 3 to 6 months. Then, he monitors your healing progress through regular follow-up visits and adjusts your care plan as needed.

Here’s how these treatments can help reduce FAI symptoms:

Targeted Exercises

Targeted exercises strengthen the muscles that support the hip joint, particularly the glutes, hip stabilizers, and core. As strength and mobility improve, pressure inside the joint decreases, which can reduce hip pain. It also improves movement patterns and limits abnormal contact between the bones. Here are some common exercises our surgeon recommends to support hip impingement recovery:

• Glute bridges
• Clamshells
• Side-lying leg raises
• Monster walks with resistance bands
• Bird dogs
• Dead bugs
• Planks

Activity Modification

Activity modification is focused on limiting movements that repeatedly trigger FAI symptoms, such as deep squats, prolonged sitting, or aggressive hip flexion. By limiting these movements, repetitive stress on the hip joint is reduced, giving the irritated cartilage and labrum sufficient time to recover. In addition, our surgeon also recommends ergonomic correction as a part of your activity modification plan. For example, you may be advised to avoid sitting on low sofas and raise your bike seat while cycling.

Corticosteroid Injections

Corticosteroid injections deliver powerful anti-inflammatory medication directly into the hip joint. This medication reduces inflammation, which decreases irritation of pain-sensitive tissues inside the joint. In many patients, pain relief from steroid injections begins within 2 to 5 days and reaches its full effect within 1 to 2 weeks.

Anti-Inflammatory Medications

Dr. Charles Ruotolo may recommend anti-inflammatory medications if severe symptoms interfere with your daily activities or targeted exercises. These medications help reduce inflammation, which can decrease pain and improve comfort during movement. Here are some common anti-inflammatory medications that may be prescribed for hip impingement:

• Ibuprofen (Advil, Motrin)
• Naproxen (Aleve)
• Meloxicam
• Celecoxib (Celebrex)
• Diclofenac

What If Symptoms Do Not Improve With Non-Surgical Treatment?

If conservative care fails to improve symptoms, Dr. Charles Ruotolo may recommend surgical intervention to repair femoroacetabular impingement. In these cases, the goal of surgery is to correct the abnormal bone anatomy, restore smoother joint motion, and address any associated soft-tissue damage. Depending on the severity of the condition, he may recommend one of the following surgical procedures:

Hip Arthroscopy

Hip arthroscopic surgery is the most common surgical treatment for femoroacetabular impingement. During this minimally invasive surgery, orthopedic surgeons make several small incisions around the hip joint and insert a camera and specialized instruments. Then they remove the excess bone and may perform a labral repair if a torn labrum is present.

Open Surgical Hip Dislocation

For chronic or more complex cases, Dr. Charles Ruotolo may recommend open surgical hip dislocation. During this procedure, the hip joint is temporarily dislocated in a controlled manner, providing complete access to the ball-and-socket joint. This approach allows surgeons to reshape extensive bone deformities and correct complex impingement patterns.

Total Hip Replacement

If hip impingement has caused irreversible cartilage loss, advanced arthritis, or severe joint damage, our surgeon performs total hip replacement. During this surgery, the damaged ball-and-socket joint is removed and replaced with artificial components. The procedure can relieve pain, restore mobility, and improve overall joint function.

How Does Surgery Correct Abnormal Bone Contact?

During hip arthroscopy, surgeons reshape the hip joint to correct the abnormal bone structures causing femoroacetabular impingement. They perform the procedure through small incisions and use specialized instruments to remove excess bone from the ball of the hip joint, the hip socket, or both. As a result, the joint moves more smoothly, which reduces friction and restores normal movement within the ball-and-socket joint.

How Long Does It Take to Recover From Hip Impingement?

Recovery from hip impingement typically takes 2 to 6 months. However, the exact timeline depends on the severity of your condition and the type of treatment you receive. For example, mild cases treated with non-operative care may improve within 4 to 8 weeks. Meanwhile, chronic or more complex cases often require 2 to 6 months for complete healing. Similarly, after hip arthroscopy or other surgical treatment, you may need at least 4 to 6 months of staged rehabilitation to resume normal daily activities, work, exercise, and sports safely.

Here are some other factors that may affect the recovery timeline of hip impingement:

• Cartilage and labral damage: Recovery may take longer if the condition has already caused significant cartilage wear or a labral tear.
• Consistency with rehabilitation: Following your exercise program regularly can improve strength, mobility, and overall recovery outcomes.
• Age and overall health: Young adults with stable health often heal faster and regain function more quickly after treatment.
• Muscle strength and flexibility: Strong hip and core muscles provide better joint support, which can speed up recovery and reduce stress on the hip.
• Activity level and occupation: Athletes and people with physically demanding jobs may require additional rehabilitation before returning to full activity.

Can You Live an Active Lifestyle After Treatment?

Yes, you can live an active lifestyle after hip impingement treatment. In fact, according to the Orthopaedic Journal of Sports Medicine, 89.7% of athletes returned to at least collegiate-level sport after arthroscopic hip surgery. However, to resume normal daily activities successfully, you must follow a structured exercise program. This program is primarily focused on hip stabilization, core strengthening, mobility, and gradual return to movement.

Visit our Deer Park Clinic to Get a Personalized Treatment Plan for Hip Impingement!

Hip impingement often starts as mild discomfort, but the damage can continue even when symptoms are manageable. Therefore, if left untreated, this condition can cause repeated friction within the hip joint, leading to cartilage loss, labral tears, chronic pain, and reduced mobility.

At Total Orthopedics and Sports Medicine, Dr. Charles Ruotolo, our Castle Connolly Top Doctor, provides diagnosis-focused care for hip impingement. He first performs a detailed physical examination and reviews your symptoms, movement limits, and pain patterns. Then, he may analyze X-rays or MRI scans to confirm the severity of your injury and identify cartilage or labral damage before developing a personalized treatment plan. Contact us or visit 2103 Deer Park Avenue, Deer Park, for expert orthopedic care.

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