Periacetabular osteotomy (PAO) is a surgical treatment for hip dysplasia, a condition where the hip joint is misaligned. In younger patients (roughly 40 and under), it can be used as an alternative to hip replacement surgery.
The hip joint is a ball-and-socket joint. The ball, at the top of the femur (thighbone) is called the femoral head. The socket, called the acetabulum, is a part of the pelvis. The ball rotates in the socket, allowing the leg to move forward, backward, and sideways. In a patient with hip dysplasia, the ball and socket do not meet at the correct angle, causing pain and restricting movement.
In a PAO, a surgeon cuts and adjust the angle of the pelvic bone so that the acetabulum and femoral head meet at an angle that allows both freedom movement and freedom from pain.