Femoroacetabular impingement (FAI) results from one or more bony abnormalities that lead to abnormal contact between the acetabulum and the femoral head or neck. The femoral abnormality is proposed to cause compression and shear stresses in the region between the labrum and cartilage, anterosuperiorly. These stresses cause a separation between the labrum and cartilage as the labrum is pushed outwards and the cartilage is pushed centrally. This eventually leads to articular degeneration and eventually global hip osteoarthritis.