The femoroacetabular impingement (FAI)
is a disorder caused by an
abnormal contact between the femoral head and the acetabulum during the
articular excursion. This dysfunction has recently been recognized as a cause
of early osteoarthritis in young patients.
Three types of impingements mechanisms are distinguished:
The different mechanisms of the impingement correspond to different
damages to the acetabular labrum and articular cartilage.
Cam, caused by an anomaly in
correspondence with the morphology of the head-neck junction of the femur, it is
observed more frequently in young males and athletes, with an average age of 30
Pincer, caused by an anomaly of
orientation or depth of the acetabulum, it is observed more frequently in
middle-aged female subjects;
Mixed, caused by the presence
of both anomalies, Cam and Pincer.
The recognition of these mechanisms of
joint damage is important in preventing early degeneration of the joint.