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
Why are the ligaments important in the AA joint?
Strong ligamentous attachments limit motion and instability
What are the major ligaments of the AA joint?
•Alar Ligament
–Attaches dens to occipital condyles
•Cruciform Ligament
–Transverse ligament with superior and inferior crus
–Attaches C1 to C2
What makes up the OA joint?
•The occipital condyles articulating on C1
What is the primary motion of the OA joint? Other motions?
•Primary motion is flexion/extension
•Sidebending and rotation will always be opposite
–Can be found in either flexion or extension
How are the condyles of CV1 laid out? Superior articular facet? Posterior aspect? Occipital condyles?
•Superior articulatory facet of C1 has anterior medial convergence.
–Posterior aspect of occipital condyles are more lateral and superior.
–Anterior aspect of occipital condyles are more medial and inferior
What are the 8 ligaments of the c-spine?
- Anterior longitudinal ligament
- Posterior longitudinal ligament
- Ligamentum flavum
- Interspinal ligament
- Intertransverse ligament
- Supraspinal ligament
- Nuchal Ligament
- Posterior atlanto-occipital membrane
What 7 mm anteriorly make up the deep musculature of the neck?
•Rectus capitis lateralis
–From TP of C1 to occiput
•Rectus capitis anterior
–From LM of C1 to occiput
•Longus Capitis
•Longus Coli
•Anterior Scalene
•Middle Scalene
•Posterior Scalene
What 6 mm posteriorly make up the deep musculature of the neck?
- Rectus capitis posterior minor
- Rectus capitis posterior major
- Obliquus capitis superior
- Obliquus capitis inferior
- Interspinalis Cervecis
- Intertransversarii Cervicis
What 6 muscles makes up the intrinsic deep posterior muscles of the neck?
–Deep
•Semispinalis (Cervicis, Capitis)
•Multifidus (Terminates at CV2)
•Rotatores (Terminates at CV2)
–Intermediate
•Longissimus (Cervicis, Capitis)
•Iliocostalis (Terminates at lower cervical vertebrae)
–Superficial
•Splenius (Cervicis, Capitis)
What is the extrinsic mm of the neck?
•Extrinsic muscles
–Descending trapezius
What 3 other muscles should we consider with the neck?
•Sternocleidomastoid (SCM)
–Sidebends and rotates the head in opposite directions when unilaterally contracted
–Flexes the head when bilaterally contracted
•Strap muscles
•Pharyngeal muscles
What 7 fascias are in the neck?
- Investing fascia
- Infrahyoid fascia
- Pre-tracheal fascia
- Buccopharyngeal fascia
- Alar fascia
- Pre-vertebral fascia – includes Sibson’s
- Carotid sheath
What 3 ganglia are in the neck and provide sympathetic innervation to the head?
•Sympathetic innervation to the head and neck
–Superior cervical ganglia
•Anterior to C1-2
–Middle cervical ganglia
•Anterior to C6
–Inferior (stellate) ganglia
•Anterior to C7
•May fuse with T1
What structure in the neck provides parasympathetic innervation to the rest of the body?
•Parasympathetic Innervation to most of the body
–Vagus nerve (CN X)
•Affected by OA and C1 somatic dysfunction
Where is the phrenic nerve? Origin and course?
•Phrenic Nerve
–From cervical plexus (3, 4, and 5)
–Exits neck between clavicular and sternal heads of SCM
Where is the greater occipital nerve? What is a clinical correllation?
•Greater Occipital Nerve
–From C2
–Can cause tension HA due to course through descending traps
•C3 may also contribute through lesser occipital nerve
Suboccipital release can affect this nerve and HAs
What is the origin and course of the brachial plexus?
•Brachial Plexus
–Contributions from cervical nerves 5, 6, 7, and 8.
–Passes between anterior and middle scalenes
Again, what are the rules for the c-spine? (3rd time it’s been mentioned, probably high yield)
•OA
–Sidebends and rotates to OPPOSITE sides (i.e. OA F SLRR)
•AA
–Only significant motion (for dysfunction) is ROTATION (i.e. AA RL)
•Typical cervical joints (C2-C7)
–Sidebend and rotate to SAME side (i.e. C3 E RSL)
What are the major landmarks that can be palpated for the c-spine? Name one for each vertebrae.
- C1 is the first transverse process palpated - posterior and medial to mastoid prominence
- C2 is the first spinous process palpated
- C3 is at the level of hyoid bone
- C4/C5 are at the level of thyroid cartilage
- C6 is at the level of cricoid cartilage
- C7 is the most prominent spinous process
Do landmarks always align exactly with anatomy?
No
What are some general considerations with palpation - vertebral width, relative size of body and transverse processes?
- Each vertebrae is about a finger’s width thick
- The body and vertebral arches are much wider than the majority of the thoracic spine.
- Transverse processes are much smaller than in other areas of the spine
To palpate the neck, what is the bottom-up approach?
Bottom up
- Locate posterior rib 1
- Follow medially to vertebrae.
- CV 7 located superior to articulation of Rib 1 with TV 1
What is the top-down approach to palpation?
Top down
- Locate mastoid process posterior to external auditory meatus
- From inferior tip of mastoid process move medially to contact CV1
What is a hangman’s fracture?
•Hangman’s Fx
–Caused by forceful extension of the neck
–Bilateral Fx of pars interarticularis
–Can result in death
What is a dens fracture?
–Results in avascular necrosis
–Concomitant cruciate ligament rupture
•Death or quadriplegia
•Children with Down Syndrome may have a congenital absence of stabilizing ligaments
What neurological injuries and resulting deformities can result from neck nerve injuries?
- Erb’s palsy (C5/C6)
- Waiter’s tip
- Winged scapula
- Long thoracic nerve (C5/C6/C7)
- Klumpke’s palsy (C8/T1)
- Claw Hand
What is a stinger/burner? Is it a spine or spinal cord injury?
•Shooting or stinging pain traveling down an upper extremity
•Possibly followed by numbness or weakness.
•Considered a spine injury
–Not a spinal cord injury
–Spinal cord injuries can result in paralysis
What is torticollis? What SD does it cause in the neck? What is the long term clinical complication?
- Unilateral SCM contracture is the most common cause of idiopathic torticollis in children
- Causes sidebending and rotation of neck in opposite directions with SCM involvement
- Can lead to top down scoliosis
What are hiccups caused by? How do you treat them?
- Can be caused by imbalance of the phrenic nerve
- Can be treated by balancing the anterior fascia of the neck
