Femoral Acetabular Impingement

Femoral Acetabular Impingement (FAI) is a condition that occurs when the bones of your hip joint do not fit together properly. Over time, this abnormal contact, also known as impingement, can lead to joint damage, labral tears, and early cartilage wear, potentially contributing to osteoarthritis if left untreated. FAI most often affects active young adults, including athletes, but it can also affect people with no history of high-level sport. Early diagnosis and tailored treatment can help reduce pain, protect your joint, and support long-term mobility.

Dr Darren Paterson offers a thorough assessment to determine whether FIA is affecting your hip joint and works with you to explore personalised treatment options that may help relieve pain and improve mobility.

Understanding the hip joint and how FAI develops

Your hip is a ball-and-socket joint. The femoral head (ball) at the top of your thigh bone normally fits smoothly into the acetabulum (socket) of your pelvis. In FAI, one or both, of these structures develop an abnormal shape, which leads to pinching during hip movement.

There are three types of FAI:

An extra bony bump forms on the femoral head, making it less round. This causes it to jam against the socket, particularly with hip flexion and rotation.

The rim of the socket (acetabulum) extends too far, leading to over-coverage and pinching of soft tissues, especially the labrum.

Both cam and pincer abnormalities are present, which is common in many patients.

This abnormal contact can occur during everyday movements such as sitting, squatting, twisting, or playing sport—and over time may lead to tearing of the labrum (the cartilage ring around the socket) and breakdown of joint cartilage.

FAI causes and risk factors

FAI usually develops during teenage growth years, when the hip bones are forming. It is not caused by anything you did wrong, but it may be more likely to occur if you:

Participated in high-impact sports during adolescence (e.g. football, dance, basketball)
Have a family history of hip conditions
Experienced childhood hip disorders (such as hip dysplasia or Perthes disease)
Have underlying joint hypermobility or previous hip injuries

Many people with FAI may not experience symptoms until their 20s or 30s, when structural contact starts to cause pain or damage.

Common symptoms of femoral acetabular impingement

Typical symptoms include:

Deep aching pain in the groin or front of the hip
Pain that worsens with activity, prolonged sitting, or hip flexion
Clicking, locking, or catching sensations in the joint
Reduced range of motion, particularly with twisting or bending
Stiffness after rest
Pain after sport or physical activity

How FAI is diagnosed

During your consultation, Dr Darren Paterson will take a detailed history and examine your hip for signs of impingement. Diagnosis is confirmed using imaging and movement testing.

Assessment may include:

X-rays

X-rays – to visualise bone shape, femoral head contour, and socket coverage

Clinical Evaluation

Clinical examination – to assess your range of motion and identify pain triggers

MRI

MRI or MR arthrogram – to assess the labrum, cartilage, and signs of joint damage

CT scan (in some cases)

CT scan (in some cases) – to create 3D models for pre-surgical planning

Accurate diagnosis is essential for determining whether non-surgical or surgical treatment is the most appropriate option.

Non-surgical treatment options for FAI

In mild to moderate cases of FAI, non-operative treatment may help manage symptoms and improve hip function, especially when structural damage is limited.

Treatment options may include:

Targeted exercises to strengthen the hip, improve posture, and reduce joint strain

Avoiding deep squats, pivoting, or repetitive flexion that worsen symptoms

Help reduce discomfort during flare-ups

These strategies aim to reduce irritation in the joint and may delay the need for surgery, particularly in early-stage FAI.

When surgery is considered for femoral acetabular impingement

If symptoms persist despite non-surgical care or, if there is significant structural damage, hip arthroscopy may be recommended to correct the bony abnormalities and address any associated labral tears or cartilage damage.

The hip arthroscopy surgical goals include:

Reshaping the femoral head and/or acetabulum to prevent ongoing impingement
Repairing or trimming the labrum to restore joint function
Preserving your native hip joint and preventing progression to osteoarthritis

Dr Paterson uses minimally invasive arthroscopic techniques to access the joint through small incisions, helping to reduce recovery time and preserve soft tissues. In some cases, open surgery may be required if the deformity is complex or advanced.

If you’re experiencing persistent groin pain, clicking in your hip, or difficulty with bending and twisting movements, an underlying structural issue such as FAI may be the cause. Early diagnosis and individualised treatment can help protect your hip joint and support your long-term mobility.

Femoral Acetabular Impingement