1b.Superficial back and posterior shoulder part II Flashcards
Describe the unique characteristics of c1. what does the dens articulate with?
no spinous process or vertebral body; anterior tubercle, FACET for dens, posterior and anterior tubercle, transverse foramen, superior articular facet. *dens is anterior and articulates with occipital condyle and the dens of the C2 or axis
describe unique characteristics of c2, what is it called?
c2 is the axis and the dens is posterior here. dens articulates with C1 at the facet for dens on C1
what is a jefferson fracture? what is it caused by?
burst fracture of the atlas (C1) ; often caused by blow to the top of the head. arch broken in one or more places
what is a type 1 fracture of the c2?
type I is an oblique fracture through the upper part of the odontoid process. avulsion fraction (fragment of bone tears away from major bone) this is mechanically stable but associated with life threatening atlantooccipital dislocation. incidence is very low at <5%. treat: hard collar immobilization for 6-8 weeks. caused by motor vehicle accidents and falls
what is the cause of odontoid fractures?
usually falls and motor vehicle accidents (C2)
what is a type II odontoid fracture?
type 2- 60% incidence; occurs at base of the densrequire halo immobilization of 12-16 weeks; internal fixation (screw dens parts back together); posterior atantodental arthrodesis may be required.
what is a type 3 c2 fracture?
type 3- 30% (more frequeent that type 1 but also rare) ; halo immobilization, internal fixation; c1/c2 arthrodesis= where you have clamps, screws or wire bolting the parts together and leaves 50% rotation/mobility
Which C spine injuries are the worst?
the higher or more superior, the higher the morbidity and mortality; craniocervical
junction injiries are the deadliest
What are symptoms, mechanism of injury and clincial findings of c-spine injuries?
a. b.
mechanism of injury: combination of flexion, extension, and rotation
symptoms: pain and inability to actively move neck, sensation of instability so patients may present holding thier head
clinical findings range: quadriplegia w/ respiratory center problems or minimal sensory/motor deficits
c.
Describe cause hangmans fracture; where is the fulcrum? What type of extension?
both pedicles are broken
being hanged, falls, or motor vehicle accidents: momentum carries body forward into windshield and rebound movement or whiplash, causes forceful hyperextension that breaks the pedicles
forced hyperextension with cervical spine as fulcrum
Know xray for hangman’s fraction/ presentations
broken bilateral pedicles forward displacement of C1
speration of upper cervical spine from lower cervical spin
how does fusion happen
Lateral mass screws and pedicle screws go at an angle and then stablize with fusion rods to connect between. This is called a fusion. Laminectomy is sometimes coupled with this (spinous process being removed therefore need stabilization)
How do you repair a hangman’s fracture?
intervention: c2 pedicle arthrodesis: lateral mass screws in c1 and pedicle screws in
c2 and 2 plates for stabilization
describe vertebral subluxation
displacement of vertebrae that can stress spinal cord and nervous system causes: poor posture and sleeping posture, mva, slips/ falls, strenous excercise,
can cause impinged nerve
why kind of joint is the anterior intervertebral joint?
synarthrosis joint: specifically a secondary cartilagenous, also known as a syphysis type joint where the bodies of adjacent vertebrae would articulate with the intervertebral disc located betwen them
what are the 2 types of cartilaginous joints?
1) Primary cartilaginous joints: (synchondrosis): In this subtype the bones are united by a plate of hyaline cartilage so that the joint is immovable and strong. These joints are temporary in nature because after a certain age the cartilaginous plate is replaced by the bone. Examples of this type of joints are joint between the epiphyses and diaphysis of a growing long bone, the costochondral joint and the first chondrosternal joint.
2) Secondary cartilaginous joints: (symphysis): These are also known as fibro-cartilaginous joints. There articular surface is covered by a thin layer of hyaline cartilage and the bones are united by fibro-cartilage. These joints are permanent and persist throughout the life of an individual. Typically the secondary cartilaginous joints occur in the median plane of the body and permit limited movements because of compressible pad of cartilage in them. The thickness of the fibro-cartilage in these joints is directly related to the range of movement the joint offers. Examples of this type of joints are; symphysis pubis, manubrio-sternal joint and intervertebral joints between the vertebral bodies.
Describe the zygapophyseal joint. what type is it?
has superior and infereior facets- the superior articulates with the inferior one above it, forming a diarthrosis joint (plane) therefore movements are gliding or sliding.
Intervertebral formaina is between adj vertebrae and allows for spinal nerves
in facet joint degeneration, what do we see at L4/5? from what view?
coronal view we see severe bilateral facet joint degeneration at L4/5 with air in the joints (show as gaps on X-ray)
How do zygapophyseal joints prevent movement? Difference btwn disc and joint? Describe regional differences
disc controls AMOUNT of movement whereas joint controls DIRECTION of movement
in cervical region- 45 degrees; transverse to frontal plane allows rotation, flexion, and extension
in throacic region- 60 degrees; front plate has sets that permit rotation
in lumbar is 90 degrees (sagittal place); sagittal plane only permits extension and flexion
what are the ligmental supports?
posterior longitudinal= NARROW band from sacrum to C2 on posterior vertebral bodies and discs
ligamentum favum= runs from lamina to lamina from axis to sacrum
anterior longitudinal= WIDE band from sacrum to occiput on anterior vertebral bodies and discs
facet joint capsule
interspinous and intertransverse= goes from spinous processes to spinous process and the intertransverese goes from transverse to transverse
supraspinous= continuous attachment to tips of spinous process from sacrum to C7
nuchal= thickened continuation of supraspinous ligament from C7 to occiput
what are the 3 region specific joints in the cervical region?
uncovertebral
atlantodental
atlantoccipital
where is the uncovertebral joint and what does it do
it prevents lateral translation and is at the uncinate procces (edge of the body) and the one above
what type of joint is the atlantodental?
synovial/diarthrotic joint of the pivot type (move in one plane about vertical axis). artculation btwn dens and posterior facet of anterior tubercle
rotation: just say no! (antlantoaxial),
what type of joint is the atlantooccipital?
synovial/diathrotic, of the condyloid type, superior articular facets of c1 articulate with the occiptal condyles on the occiptal bone of the skull
what is a condyloid joint
here articular surfaces consist of two distinct condyles in which one is convex surface (called the male surface) fitting into a concave surface (called the female surface) of the other bone. These joints mainly permit the movement in plane around a transverse axis. Example of this type of joints is knee joint.
at the atlantodental joint, the dens is held in place by
transverse ligament
DIffrence btwn pivot joint and condyle joint?
pivot joint allows movement in only 1 plane- transverse; while condyle joint allows sagittal and frontal plane movement. so this joint allows you to laterally flex but also to say yes
what is a demifacet?
partical facet; demifacet of neighboring vertebrae have rotaiton with both vertebrae
which don’t have transverse costal facets?
T11 and T12
Costovertebral joint? what region is this in?
plane joint therefore just permits linear movement of articulating surfaces past one another
ribe is wedge shaped so that each side can articulate with each demifacet
articulation btwn tubercle of rib with transverse costal facet; lateral and supiror cosotransverse ligaments support this joint.
thoracic region
what is the region specific joint of the sacral region? what type of joint is it/
sacroiliac joint is a synarthrosis type joint; auricular suface on coxa with auricular surface (resembles ear) on sacrum. with bilateral erosion of bony surfaces
what are the 2 muscle layers of the back? what is their function
1) superficial muscles/ extrinsic : they act on upper limb
2) deep/intrinsic muscles act on vertebral column
What is the function of the trapezius
superior elevation, midline retraction, and inferior depression at the shoulder girdle (not a joint)
what is the function of the throracolumbar fascia
suppors secondary curvature
what is the function of the latissimus dorsi?
extends, medial rotation, and adduction at the shoulder
what is the neuromuscular bundle
vein, artery, nerve
what is the trapezius innervated by?
spinal accessery nerve 11, ascending transverse cervical vein and artery
what is the latissimus dorsi innovated by?
thoracodorsal v, a, n (aka middle subscapular v,a,n
what is the rhomboid maj/min innervated by?
dorsal scapular v, a, n (descnding transverse cervical v, a, n)
what is the legator scapulae innervated by?
dorsal scapular v, a, n
what are the cutaneous nerves of the back?
sensory to skin, motor to sweat glands and erector pili muscles
anterior aspect of trapezius muscle: dorsal rami (come every 2 inches apart and send cutaneous innervation to the skin) ,
sensory to skin, motor to sweat glands & motor to erecto pili muscles that generate tension when you get scared and hair stands on end
Describe nerve distribution to the body wall
spinal cord supplies the cord. can see dorsal root ganglion and spinal nerve which distributes its dorsal ramus through the back muscle to the skin which it supplies and ventral ramus supplies most of the rest of the body wall
dermatome vs cutaneous
dormatome is a strip of skin that is innervated bya pair of spinal nerves.
cutaneous: areas of skin innervated by cutaneous nerve
all joint actions are at the shoulders. which are they?
deltoid: abduction, axilary nerve and posterior humerus circum
triceps brachii: lateral H, LH, profunda branch, radial nerve
what does the supraspinatus do?
initaites and ends abduction at the shoulder joint; supra scapular n/a
what does the infraspinatus do?
lateral rotation at he shoulder joint and supra scapular n/a
what does the trees minor do?
lateral rotation at the shoulder joint and axillary n (posterior branch) and scapular circumflex
teres major
medial rotation of humerus; abduction at the shoulder joint; lower sub scapular n, scapular circumflex
what are the superficial layer muscles of the extrinsic back (hypaxial) muscles? where do they all act?
trapezius, levator scapulae, rhomboideus, and latissimus dorsi
all act on the scapula or humerus and associated with movements of the upper limb and respiration
http://www.anatomyguy.com/essential-anatomy-series-back-muscle-basics-2/
trapezius
a) adducts (aka retraction) of scapula; upper portion elevates and lower portion depresses
b) innervated by spinal accessory nerve or cranial 11
c) axio appendicular : meaning it goes from spinal portion of skeleton to limb portion of skeleton
d) has upper component which wraps around clavicle, a middle component which wraps spine and scapula and inferior that wraps to root of spine of scapula.
e) elevation, retraction or depression of shoulder
latissimus dorsi
adducts (aka protraction) humerus
and medially rotates humerus
-innervated by thoracodorsal nerve (middle sub scapular n or n to lats dorsi)
levator scapula
- elevates scapula
- innervated by dorsal scapular nerve
rhomboid minor and minor; where do they attach?
minor comes from above the root of the spine of the scapula
* both attach to spinous processes of cervical vertebrae (not the transverse process like the legator does
both adduct scapula
-innervated by dorsal scapular nerve
supraspinatus and infraspinatus
supraspinatus:
initiates abduction of shoulder for deltoid
innervated by supra scapular nerve
infraspinatous:
lateral rotator of humerus
innervated by supra scapular nerve
teres minor and major
major: medial rotator and adductor of humerus
innervated by lower sub scapular nerve
minor: lateral rotator of humurus
innervated by axillary nerve
rotator cuff
supraspinatus, infraspinatus, teres minor and subscapularis
support head of humerus in glenoid
location of supra scapular nerve and artery?
on posterior view:
navy over
army under
quadrangular space
axillary nerve
posterior humeral circumflex artery
triangular space
br of scapular circumflex artery
rearrange space
triangular interval
radial nerve
profunda brachii arteyr
quadrangular space syndrome
hypertrophy of quadrangular space muscles or fibrosis of muscle edges may impinge on axillary nerve
could produce weakness even atrophy in muscles it supplies
-deltoid muscle
-teres minor muscle===> more common
could affect control that rotator cuff muscles exert on glenohumeral joint
intermediate layer of posterior back has:
why can the intermediate layer still be included?
- accessory muscles for respiration
- serratus posterior inferior (deep to latissimus dorsi) and superior (level with clavicle, deep to rhomboid)
intermediate layer of muscle but can also be included in superficial back because supplied by ventral rami or 11th cranial nerve (like in the case of the trapezius
movements of the lumbar vs thoracic and cervical
both can do lateral flexion, flexion and extension, but only the thoracic/cervical can do rotation
list all the diarthrosis/synarthrosis/amphiarthrosis joints discussed so far
diarthrosis:
1) atlantodental (pivot)
2) atlantooccipital (pivot)
3) zygophophyseal (plane)
4) costovertebral (plane)
5) costotransvere (plane)
synathrosis:
1) anterior intervertebral
2) sacroiliac jt
differentiate these terms/locations:
scapular circumflex artery supraspinatous supraspinous suprascapular nerve and artery dorsal scapular nerve
scapular circumflex artery:
muscles of scapula- teres minor and major
supraspinatous:
muscles of scapula- supraspinatous initiates abduction and is enervated by the supra scapular nerve
supraspinous:
ligament of vertebrae, connects tips of spinous processes
suprascapular nerve:
muscles of scapula, innervates supraspinatous and infraspinatous
suprascapular nerve/artery: navy over, army under
dorsal scapular nerve:
extrinsic back muscles, innervates rhomboid major/minor and levaetor scapula
on the back, the skin is innervated by ___
but the muscles are innervated by ___ except ___
skin innervated by dorsal rami
muscles innervated by ventral rami, excel the trap which is innervated by cranial nerve 11
The primary action at the atlanto-axial joint is:
The atlanto-axial joint is a complex joint with multiple articulations between the atlas (C1 vertebra) and the axis (C2 vertebra). The primary action at this joint is rotation of the head on the neck.
