3-24 Functional Anatomy of the Cervical Spine Flashcards
What limits flexion in the neck? What is the range of motion?
–Limited by the posterior longitudinal ligament
–90⁰
What limits extension in the neck? What is the ROM?
–Limited by direct contact of vertebral lamina, zygapophyseal joints (facets), spinous processes
–70⁰
What are the last 2 types of motion in the neck? Where is rotation done?
•Side-bending
•Rotation
–Approximately 50% of rotation in AA joint
–Approximately 50% rest of the cervical spine
What is a vertebral unit?
Two adjacent vertebral segments with their associated intervertebral disk, arthrodial, ligamentous, muscular, vascular, lymphatic and neural elements
How is the vertebral unit named?
•Convention – named for superior vertebra in pair
What is the main joint for the vertebral unit?
•Joint – inferior facets of superior vertebra on superior facets of inferior vertebra
Where is motion considered in the vertebral unit?
•Motion – reference point is superior anterior aspect of superior vertebra
What are the mechanics for the OA joint?
–Sidebends and rotates to OPPOSITE sides (i.e. OA F SLRR)
What are the mechanics for the AA joint?
–Only significant motion (for dysfunction) is ROTATION (i.e. AA RL)
What is the rule for movement of the typical cervical joints (C2-C7)?
–Sidebend and rotate to SAME side (i.e. C3 E RSL)
How many atypical cervical vertebrae are there? What are some special features?
–2 atypical
•Atlas (C1) – no body
•Axis (C2) – odontoid process (the dens)
How many typical cervical vertebrae are there?
–4 typical
•C3-C6
•Have uncovertebral joints both superiorly and inferiorly
How many semi-atypical vertebrae are there in the neck?
–1 semi-atypical
•C7
•Vertebrae Prominens
What are the mechanics of the typical cervical vertebrae?
•Vertebral units of C2-C7
•Primary motion is sidebending
•Sidebending and rotation are paired
–Will always go to the same side
•Will be flexed or extended
How are the facet joints laid out in typical cervical vertebrae?
•Zygapophyseal (facet) joints oriented at a 45 degree angle toward the eye.
–Posterior is inferior
–Anterior is superior
–Lateral is superior
What 4 things makes typical cervical vertebrae unique?
•Unique due to:
–Uncinate processes
–Transverse foramen
–Large vertebral foramen
–Body is convex inferiorly, concave superiorly
What are uncovertebral joints?
•AKA: Joints of Lushka, articular pillars
- Formed by inferior convex portion of superior vertebra on superior concave portion of inferior vertebra
- Concavity is formed by uncinate processes
What are the embryological origins of the dens?
•Embryologic body of C1 was dens, now attached to C2
–Can cause congenital malformations
What is the AA joint considered?
•Vertebral unit of C1 (atlas) on C2 (axis)
What is the primary motion of the AA joint?
•Primary motion is rotation
–Accounts for approximately 50% of entire neck