Biomechanics / Pathologies

Question 0

Autonomic Nervous System

Answer 0

Structure - comprised of sympathetic and parasympathetic systems

Function - involuntary component of nervous system that controls the function of the internal organs

Question 1

Spinal nerve

Answer 1

Structure - nerve exiting from the spinal cord

Function - provides sensory and motor functions

Question 2

Biphasic material-

Answer 2

One that is composed of two dissimilar elements such as bone

Question 3

Wolff’s Law

Answer 3

Bone that is not used is lost

Question 4

Spinal motion segment-

Answer 4

Functional unit of the spine

Question 5

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

True or False?

Answer 5

TRUE

Question 6

What are the components of a spinal motion segment?

Answer 6

2 adjacent vertebrae, two facet joints, IV disc, & the ligaments shared by the two vertebrae

Question 7

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

Answer 7

Because spine mechanics explain why certain areas are more prone to failure than others under certain conditions (loading, bone quality, & disease state)

Also explains why spinal deformity increases the risk of future fractures and the value balloon kyphoplasty provides.

Question 8

Explain why one vertebral fracture might result in additional fractures.

Answer 8

With increased kyphosis, the center of gravity moves farther from the axis of the spine which may throw off a person’s balance and will increase the anterior load on the vertebral body. This increased load may cause fractures in individuals w/ osteoporosis or secondary osteoporosis.

Question 9

Be able to identify “three column theory” of the spine.

Answer 9

Anterior Middle Posterior

Refer to diagram in Ch. 5 of anatomy book

Question 10

Explain what components of the vertebra make up each column 1 in the “three column theory”.

Answer 10

Column 1 - anterior longitudinal ligament, cortical and cancellous bone of the anterior half of the vertebral body, & the anterior portion of the anus fibrosus.

Question 11

Explain what components of the vertebra make up each column 2 in the “three column theory”.

Answer 11

Posterior half of the vertebral body, the posterior, longitudinal ligament, & posterior portion of the anulus fibrosus.

Question 12

Explain what components of the vertebra make up each column 3 in the “three column theory”.

Answer 12

Posterior elements of the vertebral arch including the pedicels and all the ligaments related to the vertebral arch.

Question 13

Define linear motion -

Answer 13

Occurs along a line, has only one direction, & can be stopped by an equal opposite force in the opposite direction.

Question 14

Define rotational motion-

Answer 14

Happens in a circle and is comprised of several forces that act at different times

Question 15

Define NPH -

Answer 15

Nucleus pulposus can break through a torn or weakened anulus fibrosus; can compress the nerve structures.

Question 16

Define VCF-

Answer 16

Vertebral bone in the spine collapses causing the spine to shorten and often fall forward.

Question 17

Define Schmorl’s nodes-

Answer 17

Herniations of the nucleus pulposus into the body of the vertebra immediately above or below the disc.

Question 18

Define kyphosis-

Answer 18

Hunchback

Question 19

Define lordosis -

Answer 19

Swayback

Question 20

Define scoliosis -

Answer 20

Lateral deviation of the spine

Question 21

Define arthritis -

Answer 21

Inflammation of the joints

Question 22

Define Spondylitis-

Answer 22

Inflammation of the vertebrae

Question 23

Define Spondylosis-

Answer 23

Abnormal excess development of the vertebral bone such as bone spurs or osteophytes. Can also lead to stenosis of the spinal canal.

Question 24

Define spondylolysis -

Answer 24

Congenital defect in the formation of the pars interarticularis

Question 25

Define Spondylolisthesis -

Answer 25

Vertebral body and part of the vertebral arch is displaced forward. Can cause acute compression of nerve roots

Question 26

How does a NPH progress? What is the natural disease progression for a herniated disc?

Answer 26

IVD pathology usually starts as micro fractures in the anulus fibrosus. The weakened area allows for protrusion on the anulus fibrosus into the spinal canal and / or the intervertebral foramen. The 2nd stage can be symptomatic. If the pathology persists, a hernia of the nucleus pulposus will ensue. An advanced stage of NPH occurs when a fragment of nucleus pulposus becomes dislodged and can be found as a free fragment in the spinal canal.

Question 27

What is the scope of the VCP problem (total # of patients, etc)? Why is this condition worth treating?

Answer 27

There are 700,000 spinal fractures from osteoporosis annually in the U.S. Only 1/3 of them are clinically diagnosed from each year. It's important to treat because of the reduced quality of life and increased mortality risk (the downward spiral) resulting from their first fracture.

Question 28

What is the connection between corticosteroid use and osteoporosis?

Answer 28

Corticosteroid use increases the risk of secondary osteoporosis. *corticosteroid is typically prescribed for managing inflammatory illnesses such as arthritis.

Question 29

Name 2 common cancers that contribute to spinal fractures.

Answer 29

Bone metastasis (cancer that starts in one location and migrates to bone) Multiple myeloma (cancer of plasma cells in bone marrow)

Question 30

Define osteoporosis -

Answer 30

Skeletal condition characterized by the reduction in the mass of the bone affected and an increase in the risk of fractures

Question 31

Define osteopenia -

Answer 31

A bone condition in which the concentration of minerals is diminished and the total bone mass is reduced

Question 32

How are osteoporosis and osteopenia similar?

Answer 32

Both increase risk of fracture from decreased bone mass.

Question 33

How are osteoporosis and osteopenia different?

Answer 33

Osteopenia has de-mineralized bone. Osteoporosis is normal mineralized bone.

Question 34

What are the non identifiable causes of osteoporosis?

Answer 34

- Idiopathic juvenile osteoporosis - idiopathic adult osteoporosis. - Senile osteoporosis.

Question 35

What are the identifiable causes of osteoporosis?

Answer 35

- Osteoporosis associated with an endocrine disease. - Osteoporosis secondary to malnutrition or malabsorption. - Osteoporosis secondary to paralysis or reduced muscular activity - Osteoporosis related to an inflammatory or auto immune disease

Question 36

What are the positive risk factors for osteoporosis?

Answer 36

- calcium intake - exercise - fluoride supplement - moderate alcohol consumption - obesity

Question 37

What are the negative risk factors for osteoporosis?

Answer 37

- aging - gonadal hormones - oophorectomy w/o hormone replacement therapy (HRT) - high protein diet - vitamin d deficiency - smoking