A Periosteal Elevator – its width is the length of the incision.
With the patient asleep and turned prone, a metal marker is placed over the intended level and a portable X-ray is taken to verify. The small vertical midline skin incision is deepened to the tops of the spinous processes above and below the disc level. Muscle alongside of the spine (on the side of leg pain) are then moved about an inch to the side by the above periosteal elevator. No muscle is cut or penetrated and after the procedure it is allowed to move back against the spine. Thus, the lower half of the upper lamina, the upper half of the lower lamina, and the interspace between are visualized. A metal instrument is then placed between the laminae and another X-ray is taken to double-check that interspace is the level of the herniated disc.
Disc cartilage does not show up on an X-ray, so the vertebrae are counted up from the sacrum to the level of the marker. After the correct level is confirmed the muscle is held laterally with a special retractor, to be shown in Part 2