Chapter 5

Question 1

Wolffs law

Answer 1

Bone that is not used is lost

Question 2

Spinal motion segment

Answer 2

The functional unit of the spine

Question 3

True or false:

As kyphotic deformity increases, the center of gravity moves farther from the axis of the spine

Answer 3

True

Question 4

What are the components of a spinal motion segment?

Answer 4

It is composed of two adjacent vertebrae, two facet joints, intervertebral disc, and the ligaments shared by the 2 vertebrae

Question 5

Why is understanding spine biomechanics valuable in working with surgeons and other customers?

Answer 5

It is important because spine biomechanics explain why certain areas are more prone to failure than others under certain conditions. In addition, it explains why spinal deformity increase the risk of future fractures and the value that balloon kyphoplasty provides

Question 6

Using your understanding of the biomechanics of the spine, explain why one vertebral fracture might result in additional fractures

Answer 6

With increased kyphosis, the center of gravity moves farther from the axis of the spine which may throw of a persons balance, and will increase the anterior load on the vertebral body. This increased load may cause fractured in individuals with osteoporosis or secondary osteoporosis.

Question 7

Draw a diagram which illustrates the “three-column theory” of the spine

Answer 7

Look at pic

Question 8

Biphasic material

Answer 8

One that is composed of two dissimilar elements, such as bone