Femoro Acetabular Impingement: FAI

Hello and welcome back to the ThreeSpires Physiotherapy blog where we take a look at all things physiotherapy and health related. In this blog we will be continuing looking in more depth at individual causes of hip pain. We have previously covered gluteus medius tendinopathy, hip arthritis, hip dysplasia and in this blog we will examine the last of the main causes of hip pain: femoroacetabular impingement (FAI). Before looking at how physiotherapy might be able to help with FAI we first need to have a look at exactly what it is and some anatomy.

What is FAI?

FAI is a condition of the hip where there is abnormal contact between the femoral head (the ball-shaped top of the thigh bone) and the acetabulum (the socket of the hip joint) during hip movement. This abnormal contact can lead to damage of the cartilage and labrum in the hip joint, causing pain, stiffness, and limited range of motion.

There are three main types of FAI:

1. Cam Impingement: In cam impingement, there is an abnormality in the shape of the femoral head, typically a bump or irregularity on the surface. This can cause friction and impingement when the hip is flexed or rotated.
2. Pincer Impingement: Pincer impingement occurs when there is excessive coverage or overhang of the acetabulum over the femoral head. This can occur due to a deep or protruding acetabulum, which leads to pinching of the labrum and cartilage during hip movement.
3. Mixed Impingement: Mixed impingement involves a combination of both cam and pincer impingement, where there are abnormalities in both the femoral head and the acetabulum.

What are the Symptoms of FAI?

Femoro acetabular impingement (FAI) can present with a variety of symptoms, which may vary depending on the severity of the condition and individual factors. Common symptoms of FAI include:

1. Hip Pain: Pain is the most common symptom of FAI and is often felt in the groin area, although it can also radiate to the buttocks, thigh, or lower back. The pain may be dull, achy, or sharp and can worsen with certain activities, such as sitting for prolonged periods, walking, running, or twisting movements.
2. Stiffness: Individuals with FAI may experience stiffness in the hip joint, particularly after periods of inactivity or during the morning upon waking. This stiffness can affect range of motion and make it difficult to perform daily activities.
3. Limited Range of Motion: FAI can restrict the normal range of motion in the hip joint, leading to difficulty with movements such as bending, squatting, or rotating the hip. Activities that require extreme hip flexion or rotation may exacerbate symptoms.
4. Pain with Certain Movements: Certain movements, such as flexion, internal rotation, or adduction of the hip joint, can exacerbate pain in individuals with FAI. Activities that involve repetitive hip motion, such as climbing stairs or sitting for extended periods with legs crossed, may also trigger symptoms.
5. Clicking or Catching Sensation: Some individuals with FAI may experience a clicking, popping, or catching sensation in the hip joint during movement. This sensation is often due to abnormal contact between the femoral head and acetabulum and may be accompanied by pain or discomfort.
6. Pain with Weight-Bearing Activities: Activities that involve bearing weight on the affected hip, such as walking, running, or standing for long periods, may exacerbate pain and discomfort in individuals with FAI.
7. Hip Instability: In some cases, FAI can lead to a feeling of instability or "giving way" in the hip joint, particularly during certain movements or activities. This sensation may be accompanied by a feeling of weakness or lack of control in the hip.

Who Can Get FAI?

FAI can affect individuals of various ages, but certain factors may increase the likelihood of developing this condition. While FAI can occur in both males and females, certain demographic and lifestyle factors may predispose certain individuals to FAI:

1. Age: FAI often manifests in young adults and adolescents, typically between the ages of 20 and 40. However, it can also affect older individuals.
2. Gender: While FAI can affect both males and females, some studies suggest that males may have a slightly higher prevalence of FAI.
3. Athletes and Active Individuals: Individuals who participate in sports or activities that involve repetitive hip motion, such as running, soccer, hockey, basketball, or ballet, may be at higher risk of developing FAI. The repetitive stresses placed on the hip joint during these activities can contribute to the development of structural abnormalities and impingement.
4. Structural Abnormalities: Anatomic variations in the shape of the hip joint, such as a cam-type or pincer-type morphology, can predispose individuals to FAI. These abnormalities may be present from birth or develop over time due to factors such as genetics, abnormal bone growth, or previous hip injuries.
5. Genetic Factors: There may be a genetic component to the development of FAI, as certain structural abnormalities in the hip joint can run in families. Individuals with a family history of FAI or hip disorders may be at higher risk.
6. Joint Hypermobility: Individuals with hypermobile joints may be at increased risk of developing FAI due to excessive joint movement and potential instability. Hypermobility can be a result of genetic factors or underlying connective tissue disorders.
7. Previous Hip Injuries or Surgeries: Trauma to the hip joint, such as fractures or dislocations, or previous hip surgeries can alter the anatomy of the hip joint and increase the risk of FAI.

It's important to note that while these factors may increase the likelihood of developing FAI, not everyone with these risk factors will develop the condition. Additionally, FAI can occur in individuals without any known risk factors.

What Causes FAI?

It would be fair to say that exact causes of FAI are a subject of much debate and are an area of current and active research. However we can certainly say that FAI is most likely caused by abnormalities in the shape of the hip joint, which result in abnormal contact between the femoral head (the ball-shaped top of the thigh bone) and the acetabulum (the socket of the hip joint) during movement. The cause of these abnormalities is debated and also the fact that not everyone with abnormalities in their hip joint has symptoms of FAI presents problems in being certain.

Below are some of the general factors that are thought likely to lead to FAI:

1. Cam Morphology: Cam morphology refers to an abnormality in the shape of the femoral head, where there is a bump or protrusion on the surface of the femoral head. This bump can cause friction and impingement when the hip is flexed or rotated, leading to damage to the cartilage and labrum.
2. Pincer Morphology: Pincer morphology involves an abnormality in the shape of the acetabulum, where there is excessive coverage or overhang of the acetabulum over the femoral head. This can occur due to a deep or protruding acetabulum, leading to pinching of the labrum and cartilage during hip movement.
3. Mixed Morphology: Some individuals may have a combination of both cam and pincer morphology, where there are abnormalities in both the femoral head and the acetabulum. This mixed morphology can further increase the risk of impingement and hip joint damage.
4. Developmental Abnormalities: FAI can result from developmental abnormalities in the hip joint, such as hip dysplasia or slipped capital femoral epiphysis (SCFE). In hip dysplasia, the shallow acetabulum and abnormal femoral head shape can predispose individuals to impingement. SCFE occurs when the ball at the upper end of the thigh bone slips off the rest of the bone, leading to abnormalities in the hip joint.
5. Genetic Factors: There may be a genetic component to the development of FAI, as certain structural abnormalities in the hip joint can run in families. Individuals with a family history of FAI or hip disorders may be at higher risk.
6. Joint Hypermobility: Individuals with hypermobile joints may be at increased risk of developing FAI due to excessive joint movement and potential instability. Hypermobility can be a result of genetic factors or underlying connective tissue disorders.
7. Repetitive Hip Motion: Activities that involve repetitive hip motion, such as running, soccer, hockey, basketball, or ballet, may contribute to the development of FAI. The repetitive stresses placed on the hip joint during these activities can exacerbate existing structural abnormalities and lead to impingement.
8. Previous Hip Injuries or Surgeries: Trauma to the hip joint, such as fractures or dislocations, or previous hip surgeries can alter the anatomy of the hip joint and increase the risk of FAI.

How is FAI Diagnosed?

Femoroacetabular impingement (FAI) can be diagnosed through a combination of clinical evaluation, physical examination, and imaging studies. Here's how FAI is typically diagnosed:

1. Physical Assessment:
   • Your physiotherapist, doctor or possibly a specialist nurse will begin by taking a detailed medical history, including asking about the onset and nature of hip pain, any previous injuries or surgeries, and factors that exacerbate or alleviate symptoms.
   • A thorough physical examination of the hip joint will be conducted to assess range of motion, stability, strength, and any signs of impingement or abnormalities. This may include some specialised tests such as hip impingement tests e.g FADIR and FABER
2. Imaging Studies:
   • X-rays: X-rays are typically the first imaging modality used to evaluate the hip joint. X-rays can reveal abnormalities in the bony structures of the hip, such as cam or pincer morphology, osteophytes (bone spurs), and signs of joint degeneration.
   • MRI (Magnetic Resonance Imaging): MRI may be ordered to obtain more detailed images of the soft tissues surrounding the hip joint, including the labrum, cartilage, and ligaments. MRI can help identify labral tears, cartilage damage, and other soft tissue abnormalities associated with FAI.
   • CT Scan (Computed Tomography): CT scans may be recommended in certain cases to further evaluate the bony morphology of the hip joint, particularly to assess the extent of cam or pincer morphology and the degree of impingement.
3. Diagnostic Arthroscopy:
   • In some cases, diagnostic arthroscopy may be performed to directly visualize the structures inside the hip joint and confirm the presence of FAI, assess the severity of impingement, and identify any associated intra-articular pathology, such as labral tears or cartilage damage.

Early diagnosis and intervention are crucial for managing FAI and preventing further damage to the hip joint. If you experience persistent hip pain, stiffness, or limited range of motion, particularly during activities or movements involving the hip joint, it's important to consult a physio for evaluation and appropriate management.

Treating FAI

The treatment for femoroacetabular impingement (FAI) depends on various factors, including the severity of symptoms, the presence of associated hip pathology, the individual's age, activity level, and overall health. Treatment options for FAI may include:

1. Conservative Management:
   • Activity Modification: Avoiding activities that exacerbate symptoms, such as high-impact sports or activities that involve repetitive hip motion, can help reduce pain and inflammation.
   • Physiotherapy: focusing on strengthening the muscles surrounding the hip joint, improving flexibility, and correcting movement patterns can help alleviate symptoms and improve hip joint function.
   • Nonsteroidal Anti-inflammatory Drugs (NSAIDs): Over-the-counter or prescription NSAIDs may be recommended to reduce pain and inflammation associated with FAI.
2. Injections:
   • Corticosteroid Injections: Injections of corticosteroids into the hip joint can help reduce inflammation and provide temporary relief from pain associated with FAI. However, the effects of corticosteroid injections may be short-lived and may not address the underlying cause of FAI.
3. Surgical Interventions:
   • Hip Arthroscopy: Arthroscopic surgery is a minimally invasive procedure that involves using small incisions and specialized instruments to access and treat intra-articular pathology associated with FAI. During hip arthroscopy, the surgeon may address cam and pincer morphology, repair labral tears, remove osteophytes, and address other abnormalities contributing to impingement.
   • Open Surgical Procedures: In some cases, particularly when there are significant bony abnormalities or extensive damage to the hip joint, open surgical procedures such as surgical hip dislocation or periacetabular osteotomy (PAO) may be recommended to address FAI and restore normal hip joint anatomy.
   • Hip Resurfacing: Hip resurfacing involves reshaping the femoral head and placing a metal cap over the surface, preserving more of the patient's natural bone compared to traditional total hip replacement.
   • Total Hip Replacement (THR): In cases of advanced hip arthritis or irreparable damage to the hip joint, total hip replacement surgery may be necessary. During THR, the damaged hip joint is replaced with artificial components made of metal, plastic, or ceramic.
4. Postoperative Rehabilitation:
   • Following surgical intervention, a structured rehabilitation program supervised by a physio is essential to promote healing, restore hip joint function, and optimize outcomes.
   • Rehabilitation typically includes exercises to improve range of motion, strength, and stability of the hip joint, as well as guidance on gradually returning to activities and sports.

How Can ThreeSpires Physiotherapy Help with My FAI?

Physiotherapy can be extremely useful if you have been diagnosed with FAI or suspect that you may have it and one of our physiotherapists will be able to help with:

1. Assessment & Diagnosis of FAI: this is a vital part of dealing with your FAI and the sooner you have an assessment the sooner you will know what you are dealing with. Our physiotherapists will be able to comprehensively assess your hip, make a diagnosis of the underlying cause of your pain and refer on for imaging if needed.
2. Management Plan: once a diagnosis of FAI has been made it is vital that you get a clear and comprehensive plan to begin managing your condition.
3. Exercises for FAI: your physiotherapist will be able to determine which are the most appropriate exercises for your hip and will be able to prescribe the optimum number and frequency to promote recovery.
4. Hands on Treatment: In conjunction with load management and exercises your physio will be able to use soft tissue and hands on techniques to treat any areas that have become overloaded and tight such as your back.

Okay, I hope that you have found this article about FAI helpful and it is part of a series of articles that we are completing about each of the specific causes of hip pain. Should you or anyone you know have FAI please get in touch and one of our physios would be happy to help. Just to remind you we are a home visit physiotherapy service and our physios are mobile and will come out to you at home.