1.   To prevent certain paralysis they needed to perform a series of operations to graft a spinal vertebra.

2.   Hip fractures are potentially life threatening, while crushed spinal vertebrae may lead to back pain, loss of height and mobility, and eventually curvature of the spine.

3.   Disrupting the nerve flow from the spine may cause disease, Palmer reasoned, and misaligned spinal vertebrae could put pressure on the nerves.

4.   There, the tops of five chestnut-colored spinal vertebrae jut out of the ground like the back of an old sea serpent.