Method and apparatus for spinal distraction

A method of treating the spine, comprising the steps of:

• identifying a site on the anterior surface of the sacrum;
• forming a lumen from the site into the sacrum, through a first vertebral body and into a second vertebral body;
• introducing a temporary distraction device into the lumen, the temporary distraction device comprising a proximal piece releasably connectable with a distal piece, the proximal piece having a proximal external thread with a proximal thread pitch, the distal piece having a distal external thread with a distal thread pitch that is finer than the proximal thread pitch;
• increasing the distance between the first and second vertebral body by rotating the proximal external thread into engagement with the first vertebral body and rotating the distal external thread into engagement with the second vertebral body;
• releasing the connection between the proximal piece and the distal piece;
• and
• sequentially removing the proximal piece and the distal piece of the temporary distraction device from the lumen.