Lumbar spine Flashcards
describe the vertebral coloumn
extends from the skull to the apex of the coccyx
madeup of 7cervical, 12 thoracic, 5 lumbar and 5 sacral and 4 coccygeal vertebrae
describe the curvature of the spine and its importance
the spine curves twice
the sacral and thoracic curvature is kyphosis (primary = developed from birth) they are concave anterioly
lumbar and cervical are secondary curvatures known as lordotic (lord with a big belly) , the cerival one occurs when you first look up as a baby, and the lumbar when you take your first step , they are concave posteriorly
they are imporatn for stability and maintainance of a balanced centre of gravity
describe the size and struture of the different vertebrae as you go down
at the top is cervical which is rounded
thoracic is tiranglular
lumbar which is kidney bean shaped and large to increase surface area since it undergoes more compressive weight and carries the weight of the body
sacral is fused
the processes of the vertebrae? and whats special about them
7
- 2 superior articualr processes
- 2 inferior articular processes
- 2 transverse processes
- 1 spinous process
all are lined with hyaline except spinous
draw a lumbar spine and describe it
image
4 articualr processes
a vertebrae foramen wc contains the conus medullaris, cauda equina and meninges
spinous process
the facet joints are at a 90 angle to axial plane and 45 to coronal
label this
what are the articular processes known as
how are vertebrae held to the vertebrae below it?
how much of the body’sweight is carried in an upright position by ‘x?
vertebrae end plaetes and they are covered in hyaline
intervertebral discs
1/3 by posterior elements (everything posterior to the vertebral body)
vertebral arch?
what is the function of the transvere and spinous process
protective tunnel in which the spinal cord runs
formed by 2 pedicles and 2 laminae (pedical connects to the transverse process and laminae joint to maek the spinous process)
what is the joint named when facets link?
what space do they create
zygapophyseal joint
vertebral notch - passageway for the spinal nerves from the spinal canal to the periphery
due to the arrangement of the zygapophyseal joint in the lumbar spine what movements are permitted
some lateral flexion and rotation but they are limited due to the orientation of these joints
describe the intervertebral disc
2 regions = the nucleus pulposus and annulus fibrosus
annulus fibrosus
- made up of layrees of type 1 collagen on the outside going in concentric circles where each layer is a different direction to deal with tension for a wide range of directions and then the inner lamellae of the annulus fibrosus is fibrocartilaginous
- its major function is shock absorbant
- avascaular
- stronger than the vertebral body and can resist axial (top to bottom) compression well = hence when alot of pressure is applied the vertebral body fractures and not the annulus fibrosus
nucleaus pulposus
- remnant of the embryonic notochord
- gelatinous and consists fo type 2 collagen
- high oncotic pressure
- gradually squeezes height through the day due to the mechanical pressure
- it also decreases with age
- in babies itsnt more centrally located but in adults its more posteriorly located
what angle is the intervertebral disc strong
axial pressure (top to bottom)n but not loaded tangenital angle (load at an angle)
name the ligaments of the vertbral body
posterior longitinal ligament
anterior longitindal ligament
interspinous ligament
intertransverse ligament
supraspinatous ligament
ligamentum flavum
what ligaments run along what and allow for what movement
PLL from C2 to sarcal canal = prevents hyperflexion
ALL stronger than PLL runs from anterior tubercule of atlas C1 to the sacrum and is united with ther periosteum of vertebrae body = prevets hypoerextension
interspinatous ligament = weak but highly developed in lumbar and resists hyperfelxion, icnreases the stability fot he vertebral body further, its lax in extension and taught in flexion
ligamentum flavum yellow beucase lots of elastin, stretched during flexion of spine
why do we see osteoarthiric changes of facet joints as we age
when young we transmit 80% of body weight vvia teh vertebral body and only 20% via the facet joints, but as we age the nucleolus pulposus dehydrates and decreases in size and so we transmit 65% of weight in our vertebral body and 35% trhoguh facet joints, thats alot more weight = more stress c those osteoarthitic changes
why do our secondary curvatures reutn back to their primary curvatures and what is this called?
senile kyphosis
as we age the nucleolus pulposus becomes dehydrates and becomes thinner and undergoes degeneration along side the intervertebral disc, this causes the discs to undergo degeneration causeing loss of height, and some patients even undergo osteoporotic vertebral compressionof the fractures, resulting in a wedge-shaped vertebrae
this disc atrophy with or without osteoporotic fractures mean that secondary curvatures start to disappear and continued primary curvature
label this spine
why are the curvatures of our spine balanced?
what are the weak points of the spine?
to prevent falling and aid walking
C1/C2 C7/T1 ,T12/L1 L5/S1
what scan do you use for:
- normal bones
- herniation
- stenosis
- fracture
- inflammatory bone like infection
- sites where primary tumours have metastatised to bone
- x ray
- MRI
- MRI
- x ray
- isotope bone scan
- isotope bone scan
mechanical back pain
% sufferers?
- very common 50% ofthe population have suffred with lumbar pain for at least 24hrs
- 1/2 of those episodes last more than >4wks
- 80% of population have lumbar pain lasting >24 hrs in their lifetime
what is mechanical back pain and how does it present
pain when spine is loaded, that worses when exercising and is relieved with rest
- intermittent and is triggered by innocuous acitivity
- risk factors are obesity, incorrect manual handling technqiues, poor posture, sedentary lifestyle with deconiditoning of the paraspinal (core) muscles, poorly-designed seating
degenerative changes of the verebrae coloumn
- nucleolus pulposus dehydrates and decompresed and degenerates with age
- annulus f. degenrates with age
this causes :
- decreases size of IV disc
- budlging of the disc
- alteration of the load stresses on the joints
- osteophytes (bone spurs) can develop adjascent to the end plates of te discs known as syndesmophytes
- increased stress on the facet joints causes osteoarthritic changes - this is paintful because facetjoints are innervated by menigeal branch of thespinal nerve so arthitis of these joints is perceived as painful
- due to the osteoarthiris of the facet joints and the decrease in the height of the IV disc the intevertrbral foramen decreases in size and so you can compress the spinal nerve, this is percieved as radicular or nerve pain
why is osteoarhitis of the zygapophyseal painful
because these facet joints are innervated byt the meningeal branch of the spinal nerve
herniation of the IV aka x?
x = slipped disc
- pain occurs due to the herinated disc material pressing on the spinal nerve
- most common age group is 30-50 and 90% ofcases solved by 3 montns
- 4 stages:
-
disc degeneration: chemical changes int he disc so it decreases in size as it dehydrate
- prolapse : protrusion of the nucleolus pulposus occurs c slight impingement of the spinal canal but the annulus fibrosus contains the nucleolus pulposus within it
- extrusion: nucleolus pulposus breaks throught he annulus fibrosus but is still contained within the disc space
- sequestration: nucleolus pulposus separates from the main disc body and enters into the spinal cana
most common locations for hernation and why?
most vulnerable nerve roots?
L4/L5 L5/S1 because of the mechanical loading at these joints
- where they cross the IV disc = paracentrally
- where they exit the spinal canal via the IV forament = far laterally
