Orthopedic perspectives on femoroacetabular impingement.

Femoroacetabular impingement (FAI) is a cause of hip pain in which there is abnormal and repetitive contact between the proximal femur and the acetabulum. FAI can occur as a primary condition in children with distinct anatomical abnormalities or can occur as a secondary process in cases of developmental hip conditions or trauma. There are two main categories of FAI, cam and pincer, which are distinguished based on whether the anatomical abnormality is on the femoral side or the acetabular side of the hip joint, respectively. Good outcomes have been achieved with early surgical intervention, but once advanced degenerative changes have occurred the chances for a successful surgical outcome are severely diminished. The orthopedic surgeon's ability to appropriately treat FAI depends on an accurate understanding of the etiology and features of each child. The ability to make an early, accurate diagnosis is enhanced with the use of imaging modalities such as radiographs, MRI and CT. This review will focus on orthopedic perspectives in the use of these imaging modalities in defining the anatomical features of and guiding treatment for FAI.