Trunk Arthrology

Question 1

Anterior Longitudinal Ligament (ALL)

Answer 1

1. Extends from basilar occiput and anterior tubercle of atlas to sacrum
2. Runs along anterior surface of vertebral bodies and discs (has
   attachments to both bodies and discs): thickest centrally, but extends
   to IVF
3. Becomes wider distally
4. Limits extension (only ligament to limit extension)

Question 2

Posterior Longitudinal Ligament (PLL)

Answer 2

1. Runs from axis to sacrum
2. Attaches primarily to discs, some attachment to posterior aspect of
   vertebral bodies
3. Narrower and weaker than ALL, broadest in thoracic region
4. Continuous with tectorial membrane in upper cervical region
5. May limit flexion, limits posterior herniation of discs
6. Well innervated with pain receptors

Question 3

Supraspinous Ligament

Answer 3

1. Runs along the spinous processes from C7 to sacrum
2. Limits flexion

Question 4

Ligamentum Nuchae

Answer 4

1. Continuation of supraspinatus ligament in cervical region ( C6 to occiput)
2. blends with interspinous to hold neck in extension

Question 5

Interspinous Ligament

Answer 5

1. Between adjacent spinous processes
2. Blends with interspinales muscles -> helps hold space between vertebrae
3. Intertransverse ligament serves a similar role between transverse processes

Question 6

Ligamentum Flavum

Answer 6

1. Highly elastic (yellowish) fibers
2. Attaches from anterior surface of lamina above to posterior surface
   of lamina of segment below
3. Limit rapid flexion of spinal column
4. Thickest in lumbar region

Question 7

Intervertebral Discs

Answer 7

1. account for 20-25% of spine length
2. shock absorbers, help disperse forces
3. provides strong attachment between vertebral bodies
4. permits movement between vertebrae
5. consists of the outer annulus fibrosus and the inner nucleus pulposus
6. 80% water in younger individuals
7. wider anteriorly in the lumbar and cervical regions helping to form the spinal curves

Question 8

Anulus Fibrosis

Answer 8

1. Fibrous concentric rings of fibrocartilage around the circumference of
   the disc
2. Fibers in each lamella run obliquely at 60°-90° angles to stabilize
   during rotation, fibers run 30° off vertical to allow rotation b/t
   adjacent vertebral bodies
3. Outer 1/3 has sensory innervation; vascularization decreases as one
   moves centrally
4. Thicker anteriorly than posteriorly
5. Attach to hyaline cartilage (end plates) on the vertebral bodies
6. Also have attachments to the anterior and posterior longitudinal
   ligaments

Question 9

Nucleus Pulposis

Answer 9

1. Fibrogelatinous inner portion: approximately 80 - 88% water (higher
   in younger individuals, reduces with age)
2. Avascular (receives nutrition via diffusion)
3. Serves as a fulcrum during movement

Question 10

Articulations in the trunk between vertebral bodies

Answer 10

symphysis joints

Question 11

facet joints (zygophyseal joints)

Answer 11

1. planar/gliding joints
2. joint capsules innervated by dorsal rami of that spinal level
3. thoracic movement is greatly limited due to the bony elements and articular facets

Question 12

costovertebral joint

Answer 12

1. planar/gliding joints between rib and vertebral bodies
2. reinforced by the radiate ligaments
3. each rib articulates with its names vertebra and the one superior to it

Question 13

costotransverse joint

Answer 13

1. planar/gliding joints between tubercle of rib and transverse process of vertebra
2. reinforced by the costotransverse (superior, medial, and lateral) and intra-articular ligaments

Question 14

sternocostal joint

Answer 14

1st sternocostal = synchondrosis
2-7 sternocostal = synovial joints

Question 15

constrochondral joint

Answer 15

synchonroses = little or no movement

Question 16

interchondral joint

Answer 16

1. at the borders of the costal cartilages 6-9
2. synovial planar joints

Question 17

manubrialsternal joint

Answer 17

symphysis or may be ossified

Question 18

xiphisternal joint

Answer 18

synchondrosis or may be ossified

Question 19

cervical movement and range

Answer 19

1. Rotation: 90°
2. Sidebending: 40-75°
3. Extension: 90°
4. Flexion: 45-50°
5. Coupled movements: in lower C-spine (C3-C7): sidebending and
   rotation are coupled in the same direction
   a. Coupled movements allows greater range than either
   movement alone

Question 20

thoracic movement and range

Answer 20

1. 3-20° flexion/extension
2. 5-10° sidebending
3. 35-50° rotation
4. Coupled movements are highly variable

Question 21

lumbar movement and range

Answer 21

1. 40° flexion
2. 20° extension
3. 10-20° rotation

Question 22

movements of the ribs

Answer 22

1. Rotation and elevation/depression occur at costovertebral and
   costotransverse joints
2. Movements with respiration
3. Upper joints (T1-T6) increase the anterior-posterior diameter = pump handle
   movement
4. Lower joints (T7-T12) increase the medial-lateral diameter = bucket handle
   movement

Question 23

Arterial supply to the spine

Answer 23

Branches of segmental arteries (arteries coming off the thoracic aorta at
each vertebral level)

Question 24

venous drainage of the spine

Answer 24

Intervertebral veins receive drainage from spinal cord and from vertebral
venus plexus

Question 25

zygophyseal (facet) joint innervation

Answer 25

articular branches off of segmental posterior primary rami (PPRs)`

Question 26

vertebral column innervation

Answer 26

recurrent meningeal branches of segmental spinal nerves (arise immediately after dorsal and ventral roots join to make mixed spinal nerve)

Question 27

clinical considerations

Answer 27

a. Osteoporosis b. Laminectomy c. Disc Protrusion d. Spondylolysis (pars interartciularis fracture) e. Spondylolisthesis (anterior slippage of vertebral body) f. Lumbar Puncture