Coxa profunda refers to a deep acetabular socket. On pelvis x-rays it is seen as the acetabular fossa being medial to the ilioischial line. It should be differentiated from protrusio acetabuli, where the femoral head is seen additionally medial to the ilioischial (Kohler's) line. Coxa profunda is much more common in females.
Coxa profunda is a non-specific finding and has previously been implicated in pincer-type femoroacetabular impingement, but is just as likely to be seen in asymptomatic patients .