Facet Joints

Question 1

Facet Joints

Answer 1

Formed by two adjacent articular joints

Question 2

Synovial Joints

Answer 2

Facet joints are surrounded by capsule of connective tissue that produces a flute to nourish and lubricate joint
-coated with cartilage (hyaline) to allow smooth guiding (articulate)

Question 3

Motion Segment

Answer 3

Smallest physiological motion unit in spine, 25 in human spine
-2 vertebral bodies
-1 disk
-2 facet joints
-ligaments
Occipital (base of skull) and C1 (no disk), C1 and C2 (no disk), and L5 and sacrum are not motion segments (not a single disk)

Question 4

Facet Orientation

Answer 4

Cervical Facets; 45 degrees horizontal, gives cervical spine mobility in all directions
Thoracic Facets: 60 degree axial, 20 degrees frontal
Lumbar Facets: 90 degree axial, 45 degree frontal, limits rotation

Question 5

Facet joint load

Answer 5

20 percent of axial load, prone to degeneration later in life