Femoroacetabular impingement (FAI) syndrome, commonly referred to as hip impingement, is a movement-related disorder of the hip joint. It occurs when there is symptomatic contact between the head of the femur and the acetabulum during hip movement. This abnormal contact can irritate surrounding structures such as cartilage and the labrum, leading to pain and functional limitation.
FAI syndrome is defined by the combination of symptoms, clinical examination findings, and imaging features. Importantly, imaging changes alone are not enough for diagnosis. Physiotherapy for FAI syndrome focuses on reducing symptoms, improving hip control, and optimising movement patterns to allow people to remain active and avoid progression.
Key Facts
Risk Factors
- Participation in sports involving deep hip flexion or rotation
- Reduced hip strength or control
- History of hip pain or previous hip injury
Symptoms
- Pain in the hip or groin associated with movement or certain positions
- Pain that may be felt in the buttock, thigh, or lower back
- Clicking, catching, or locking sensations in the hip
- Hip stiffness or reduced movement
Aggravating Factors
- Prolonged sitting, especially in low chairs
- Deep hip flexion such as squatting or tying shoes
- Twisting or pivoting on the affected leg
Causes
FAI syndrome occurs when the shape of the hip joint leads to repeated contact between the femoral head and the acetabulum during movement. This contact can irritate joint structures and cause pain. There are two main morphologies associated with FAI syndrome.
CAM morphology involves extra bone or flattening at the head-neck junction of the femur. Pincer morphology involves extra bone on the rim of the acetabulum, resulting in over-coverage of the femoral head. Some individuals have a combination of both. These morphologies alone do not cause symptoms unless they are associated with pain and functional limitation.
How Is It Diagnosed?
Diagnosis of FAI syndrome requires a combination of clinical assessment and imaging findings. A physiotherapist will assess hip range of motion, muscle strength, movement control, and functional tasks such as walking and single-leg activities.
Specific hip impingement tests are commonly used during assessment. A diagnosis is only made when clinical signs and symptoms are consistent with findings seen on imaging.
Investigations & Imaging
- X-ray
- Used to identify CAM or pincer morphology of the hip joint
- MRI or CT
- Assesses cartilage, labrum, and other joint structures to determine the extent of damage
Physiotherapy Management
Physiotherapy is the first-line treatment for femoroacetabular impingement syndrome. Management focuses on reducing pain, improving hip stability and control, and modifying activities to reduce impingement during daily life and sport.
Exercise
Exercise rehabilitation for FAI syndrome targets muscle strength, control, and coordination around the hip, pelvis, and lower back. Strengthening programs are based on individual assessment findings and aim to improve movement quality while avoiding painful impingement positions.
Activity Modification
Activity modification is an important component of physiotherapy for FAI syndrome. Physiotherapists help identify aggravating positions and tasks, such as prolonged sitting in low chairs or deep squatting, and provide practical strategies to reduce hip stress.
Manual Therapy
Manual therapy may be used to address secondary stiffness or pain in the hip, pelvis, or lower back. This can help optimise movement and support active rehabilitation rather than directly changing joint shape.
Dry Needling
Dry needling may be used to reduce muscle spasm and pain around the hip and pelvis, particularly when muscle guarding is limiting movement.
Heat & Ice
Heat or ice may be recommended for short-term symptom relief depending on whether muscle tension or inflammation is the dominant contributor.
Education
Education is central to physiotherapy for FAI syndrome. Understanding why certain movements cause symptoms and how to modify load helps people remain active and engaged in their rehabilitation.
Other
Physiotherapists also guide graded return to sport and higher-level activities based on symptoms and functional testing.
Other Treatments
Anti-inflammatory medications or cortisone injections may be used in some cases to reduce inflammation and pain, allowing improved participation in physiotherapy. These must be discussed with and managed by a medical practitioner.
Surgery
Surgery may be considered if symptoms persist despite comprehensive conservative management. Surgical procedures aim to correct hip morphology and repair damaged structures. Physiotherapy is essential for rehabilitation following surgery.
Prognosis & Return to Activity
Many individuals with FAI syndrome experience significant improvement with physiotherapy and return to full activity. Without appropriate management, symptoms may gradually worsen and function may decline. The long-term outlook varies, with CAM morphology linked to hip osteoarthritis risk.
Complications
- Progressive hip pain and reduced activity tolerance
- Labral and cartilage damage
- Development of hip osteoarthritis over time
Preventing Recurrence
- Avoid prolonged positions that cause hip impingement
- Maintain hip and core strength to optimise joint control
- Seek early physiotherapy for persistent hip or groin pain
When to See a Physio
- Persistent hip or groin pain with movement
- Hip pain affecting sport or daily activities
- Clicking or catching sensations in the hip