Femoro-acetabular impingement (FAI)
Understanding this condition
Femoro-acetabular impingement (FAI) is a morphological abnormality of the hip that creates a mechanical pinching effect with every movement. Either the femoral head has a bump at its junction with the neck (Cam type), the edge of the bony socket is over-covering (Pincer type), or both are combined.
With every flexion or rotation, these two bony structures come into conflict and pinch the soft tissues of the joint, in particular the fibrocartilaginous ring known as the labrum.
Symptoms
The pain is typically in the groin crease, sometimes described by the patient as a C-shape when they place their hand around the hip. It appears mainly when sitting for long periods, getting into a car, crossing the legs, or during wide-range movements (sport, stretching).
The hip gradually loses flexibility, particularly internal rotation. In athletes, performance decreases: pain when squatting, running, or changing direction.
How can it progress?
Repeated impingement eventually damages the labrum (which may tear) and then the adjacent cartilage. This is one of the main causes of hip osteoarthritis in young adults and athletes.
Without correction of the morphological abnormality, the wear mechanism continues: what was only a mechanical impingement becomes early hip osteoarthritis, sometimes by the age of 35–45.
Treatment options
Treatment always starts with non-surgical options: adaptation of sporting activity, targeted physiotherapy to strengthen the gluteal and deep hip muscles, anti-inflammatory drugs during flare-ups. This is sufficient in some cases.
If pain persists and a labral or cartilage lesion is confirmed on imaging, arthroscopic surgery can correct the bony abnormality and repair the labrum through two or three small incisions. The aim is twofold: to relieve pain and preserve the hip for the future. A specialist consultation clarifies the indication.