This xray was taken just after a bilateral pelvic osteotomy. For this surgery, the pelvis is cut, rotated and a piece of donor bone is inserted. This is all held together with pins. At 1 is the cut through the pelvis. Next to the arrows you can see that the bone lines are not continuous due to the rotation. The donor bone is difficult to see and is on the outside of the pelvis behind where the pins touch, or cross. 2 shows the hip socket that has been "enhanced" from its previous insufficient development. 3 points to the 2 pins, or K wires, that are used to hold together the bones on each side.