Clinical Anatomy: Spine Flashcards
how many vertebrae
33
what are the sections of the vertebral column
7 cervical 12 thoracic 5 lumbar 5 sacral (fused) 4 coccygeal (fused)
what are the normal 4 curves of the spine
cervical (lordosis)
thoracic (kyphosis)
lumbar (lordosis)
sacral (kyphosis)
when do kids develop secondary spine curves
at about 1 year- when start walking develop a lordosis in the lumbar spine
what is atypical about vertebra prominens (C7)
no foramena transeverse process (does not transmit the vertebral artery)
has long spinous process that is non bifid (rounded tubercle)
what are the components of the intervertebral discs
annulus fibrosus surrounding inner gelatinous nucleus pulposus
what movements happen at the spine joints
flexion, extension and lateral flexion at facet joints and intervertebral discs- cumulative effect
why is there less flexion/ extension in the thoracic spine
constraint of the ribs
why is lumbar rotation less than thoracic rotation
more vertically orientated facet joints
what part of spine allows the greatest movement, why?
cervical spine, more horizontal facet joints
what happens to water content in the intervertebral discs over time- what does the lead to
decreases- overload facet joints, second degree OA
in what position is OA pain the worst
when spine extended- standing up straight
is OA usually multilevel or in one area of the spine
multilevel
what is a role of the annulus pulposus
distribute stress and weight load
where is degeneration with age most commonly seen in the spine
L4/5 and L5/S1
why is MRI not diagnostic for intervertebral disc age degeneration
as asymptomatic people will have e.g. bulging discs, disc extrusion, nerve root compression
where are you most likely to get acute disc prolapse
L4/5 or L5/S1
what causes an acute disc prolapse
lifting heavy object- annulus tear- may/ may not feel twang- nerve symptoms
what is an acute disc prolapse
when nucleus pops out of annulus fibrosis
what are the symptoms of an acute disc prolapse
pain on coughing
what is the treatment of an acute disc prolapse
most settle within 3 months with physio and conservative therapy
why is surgery avoided in acute disc prolapses
due to proximity to spinal chord
where do motor neurones originate from
anteriorly- bodies in anterior grey horn
where do sensory neurones originate from
dorsally- bodies in dorsal root ganglion
where does the spinal chord run
in spinal canal formed by the vertebral foramina
where is the cauda equina found
cauda equina can be found in the bottom third of the spinal canal and from the T12/L1 vertebrae to the coccyx, beyond the conus medullaris into the lumbar region
how do spinal nerves (formed form anterior and posterior (dorsal) roots) exit the spinal canal
via the intervertebral foramen
where does the spinal chord end
conus medullaris (tip of spinal chord) at L1
what symptoms does compression of cauda equina produce (cauda equina syndrome)
bowel and/or bladder dysfunction
lower back pain and sensory/ motor defects
lower limb weakness and sensory defects
sexual dysfunction
bilateral lower motor neurone signs
saddle anaethesia
what forms mixed spinal nerves
anterior and posterior (dorsal) nerve roots
describe the nerve roots in the lumbar spine
(cauda equina) sensory and motor nerve roots run together with 2 pairs at each level susceptible to compression
what do upper motor neurones cause when compressed
weakness, spasticity, increased tone, hyperreflexia
what do lower motor neurones (connect stem to muscle cells) cause when compressed
weakness, flaccidity, loss of reflexes
what nerve would a far lateral disc prolapse affect
the exiting nerve root
what nerve would a central compression affect in the spinal chord
thecal sac and traversing root (going to lower level)
what is the path of the exiting nerve root
outside the thecal sac, passes under the pedicle of the corresponding vertebra (e.g. L4 root passes under L4 pedicle)
what is the path of the traversing nerve root
in thecal sac, positioned anteriorly in lateral recess (in prep to penetrate the thecal sac and becoming next exiting nerve root)
is if the exiting or traversing root that is commonly affected in a disc prolapse
traversing (so L5 root affected in L4/5 prolapse, S1 compressed in L5/s1 prolapse)
what does nerve compression result in
a radiculopathy resulting in pain down the sensory distribution of the nerve root (dermatome)
weakness in any muscle supplied- myotome
reduced/ abscent reflexes (LMN signs)
what is sciatica
radiating pain down sensory distribution of sciatic nerve root (dermatome) in the lower limb
what myotome allows hip flexion
L2,3
what myotome allows hip extension
L5,S1
what myotome allows knee extension
L3,4
what myotome allows knee flexion
L5,S1
what myotome allows dorsifelxion
L4,5
what myotome allows plantar flexion
S1,2
what myotome allows foot inversion
L4,5
what myotome allows foot eversion
L5, S1
what nerve roots contribute to sciatica
L4,5 and S1 (plus S2,3)
what is spinal stenosis
when nerve roots are compressed by osteophytes in osteoarthitis and hypertrophied ligaments in OA
what are the feature of neurogenic claudication
radiculopathy or burning leg pain on walking (seen in spinal stenosis)
what is myelopathy
an injury to the spinal cord due to severe compression that may result from trauma, congenital stenosis, degenerative disease or disc herniation
what is cauda equina syndrome caused by
pressure (usually prolapsed disc) on all lumbosacral nerve roots at level of lesion including sacral nerve roots for bladder and bowel control
what exam must you do if you suspect cauda equina syndrome
PR
what are the msucles of the erector spinae
iliocostalis
longissium thoracis
spinalis thoracis
what do the muscles of the erector spinae allow
flexion and extension
what ligaments contribute to spinal stability
anterior longitudinal lig posterior longitundinal lig ligamentum flavum supraspinous lig interspinous lig
what happens when bones are in tact but ligaments torn (chance fracture)
spine very unstable, creates gibbus deformity (kink in spine), may need surgical stabilisation
where should you try to do lumbar puncture and spinal anaesthesia
posterior iliac crest L4 to avoid the spinal chord
PSIS S2
what are the bone causes of back pain
fracture (trauma, osteoporosis)
spondylolistesis
tumour
infection
what are the joint causes of back pain
spondylosis and OA
spinal stenosis
what are the muscle and ligament causes of back pain
sprains and strains
what are the disc causes of back pain
discogenic back pain
sciatic
cauda equina syndrome
what is the most common cause of back pain- describe it
mechanical- related to joints, ligaments and muscles no red flag features
worse with activity, relieved by rest, tends to be long course of relapsing and remitting
what might mechanical back pain be related to
obesity, poor posture, poor lifting technique
what is the treatment for mechanical back pain
analgesia, physio, chiropractor, pain clinic
NO SURGERY
what are back pain red flags
history of cancer, weight loss, night sweats, bladder/bowel problems
what causes of back pain can be helped by surgery
discectomy or decompression good fro sciatica/ leg pain which doesn’t settle with 3 months conservative management
how can you tell radiating mechanical back pain from sciatica
sciatica shouldn’t go past knee
what is the special features of C1
facet for articulation with occipital bone
what movement does the atlanto-occipital joint do
nodding head
what is the special feature of C2
ondontoid process (dens)
what type of joints are facet joints
synovial
what type of joints between the vertebral bodies
cartilaginous joints
what are the ligaments of the vertebral column
posterior longitudinal ligament anterior longitudinal ligament ligament between flavum (between laminae) supraspinatus ligament interspinous ligament
what spinal nerves form plexuses
anterior rami of spinal nerves
what are the three layers of meninges covering the spinal cord
pia matar
arachnoid mater
dura matar
