Clinical anatomy of the spine Flashcards
do all spine curvatures develop at the same time?
no
develop at time with movement - walking etc
what are the 2 atypical vertebrae?
atlas
axis
what is the vertebra prominens?
C7
no formaena transverse process (vertebral artery)
bifid spinous process is found where?
cervical vertebrae
what types of joint is the IV joints?
fibrocartilaginous
what do facet joints allow?
flexion, extension and lateral flexion at the facet joints and IV discs - cumulative effect
is there more less flexion in the thoracic spine compared to the cervical spine? why?
less
due to constraint of ribs
which area has the least rotation?
lumbar
due to more vertically orientated facet joints
what gives cervical spine its large rotational ability?
more horizontal facet joints
what happens to IV disc structure with ageing?
loss of water
what can loss of water in the IV joints cause?
overload of facet joints
2 degree OA?
what are the features of a problem with facet joints?
pain which is eased by flexion of the spine
what features suggest IV disc problem?
pain worse with extension of spine
how can OA be treated if in one or two motion segments?
localised fusion
inconsistent results and causes stiff movement
what are the 2 parts of the IV disc?
outer annulus fibrosis
inner gelatinous nucleus pulposis
which vertebra does a disc bulge affect?
the vertebra below
where is IV disc degeneration most common in the spine?
L4/5 and L5/S1
what are the signs of IV disc degeneration?
60% asymptomatic over 45 y/o have bulging discs on MRI
10% have disc extrusion
5% have asymptomatic nerve root compression
is an MRI diagnostic of IV disc degeneration?
no
what causes a disc prolapse? how can this present?
nucleus pops out of annulus fibrosis
lifting a heavy object can cause an annulus tear (twang) which can disrupt the rich innervation of the outer annulus resulting in pain in coughing
do all prolapsed discs need surgery?
no
most settle within 3 months
where do motor neurons originate?
anteriorly
bodies in anterior grey horn
where do sensory nerves originate?
dorsally
bodies in dorsal root ganglion
what forms the mixed spinal nerve and where does this exit?
anterior and posterior roots
exits via IV foramen
what nerves run in the lumbar spine?
cauda equina
sensory and motor nerve roots run together with 2 pairs at each level
susceptible to compression????
where does the spinal cord end and what does it become?
L1
becomes cauda equina
what is the cauda equina?
junction between the upper and lower motor neurons
what would a lateral IV disc prolapse compress?
exiting nerve root
what would a central IV disc prolapse compress?
traversing nerve root (traveling through thecal sac)
most common
what is the thecal sac?
membranous sheath which surrounds the spinal cord and cauda equina in the spinal canal
where does the exiting nerve root pass?
outside thecal sac
passes under the pedicle of the corresponding vertebra
where does the traversing nerve root pair travel?
inside the anterior thecal sac (lateral recess)
will later penetrate the sac and become exiting nerve root
what does a nerve root compression cause?
radiculopathy resulting in pain down dermatome of the nerve root (e.g sciatica)
weakness in any muscle supplied (myotome)
reduced or absent reflexes (LMN signs)
what nerves contribute to the sciatic nerve?
L4,L5, S1, S2, S3
what is spinal stenosis and what can cause it?
compression of spinal nerves
can be caused by OA
- osteophytes
- hypertrophied ligaments
what are the symptoms of spinal stenosis?
radiculopathy or burning leg pain on walking (neurogenic claudication)
what is cauda equina syndrome?
pressure on all lumbosacral nerve roots at level of lesion including sacral nerve roots for bladder and bowel control
- usually caused by prolapsed disc
what are the symptoms of cauda equina syndrome?
bilateral lower motor neuron signs
bladder and bowel dysfunction
saddle anaesthesia
loss of anal tone
what are the 3 important superficial muscles which make up the erector spinae?
iliocostalis
longissimus thoracis
spinalis thoracis
what are the main ligaments of the spine?
anterior and posterior longitudinal ligaments
ligamentum flavum
infraspinous ligaments
supraspinaous ligament (most posterior)
what do the spine ligaments do?
contribute to stability
what is a chance fracture?
fractured vertebral body with disruption of posterior ligaments, with or without fracture of posterior elements (bones intact but ripped all the ligaments, creating gibbus deformity)
how can a chance fracture be treated?
lumbar puncture and spinal anaesthesia at level of posterior iliac crest (L4) or PSIS (S2)
(want to do it in equina area)
is most back pain mechanical or inflammatory?
mechanical
discectomy and decompression surgery is good for what?
sciatica/leg pain which doesn’t resolve within 3 months with conservative management
where does sciatica pain go?
below the knee
most common feature in asymptomatic middle aged patients?
disc bulge > disc protrusion > disc extrusion > nerve root compression or deviation
