[Femoroacetabular impingement in 2024 : concept and diagnosis]

Femoroacetabular impingement (FAI) is a condition that predominantly affects young people between the ages of 20 and 40. It is characterized by hip pain associated with reduced range of movement of the hip joint. If left untreated, FAI leads to osteoarthritis. When first described in the scientific literature in 2003, the concept of FAI was based on two different anatomic features: cam-type deformity and pincer-type deformity. Since that initial description clinical experience and scientific investigation have identified a third pillar of FAI: abnormal femoral torsion. This first article reviews the concept and diagnosis of FAI.