Spine Flashcards
What are the sections of the vertebral column?
Cervical 7 Thoracic 12 Lumbar 5 Sacral 5 Coccygeal 4
Which sections of the spine are the most mobile?
Cervical
Lumbar
What are the functions of the vertebral column?
- Protect spinal cord
- Haemopoiesis
- Supports skull, pelvis, upper limbs and thoracic cage
- Movement
What are the movements of the lumber spine?
Flexion & extension
Lateral flexion
Rotation
What are the typical features of a lumbar vertebrae?
Large kidney-shaped vertebral body
Short, blunt spinous process
Triangular foramen
What is the composition of the vertebral body?
90% cancellous bone - light
10% cortical bone
Why does the size of vertebral bodies increase superior to inferior?
Increased compression forces
Lumbar are weight-bearing
The superior and inferior articular joints are strengthened by which ligament?
Ligamentum flavum
What is the composition of intervertebral discs?
70% water
20% collagen
10% proteoglycans
What are the central and peripheral regions of the discs called?
Nucleus pulposus
Annulus fibrosus
What is the nucleus pulposus made from?
Remnant of the notochord
Type 2 collagen
What is the annulus fibrosus made from?
Lamellae of annular bands
Outer = type 1 collagen
Inner = fibrocartilage
Which is stronger, the anterior longitudinal ligament or the posterior longitudinal ligament?
Anterior
What is the function of the anterior longitudinal ligament?
Prevents hyperextension
What is the function of the posterior longitudinal ligament?
Limits hyperflexion
What is the ligamentum flavum made up of?
Elastic fibres
Where is the ligamentum flavum located?
Between laminae of adjacent vertebrae
Which region of the spine are interspinous ligaments most developed?
Lumbar region
What is the primary curvature?
Kyphosis
What is the secondary curvature?
Lordosis
Which 2 regions of the spine demonstrate secondary curvature?
Cervical and lumbar
When might physiological exaggeration of lumbar lordosis occur?
Pregnancy
What level does the spinal cord finish?
L1/L2
Where should you carry out a lumbar puncture and why?1
L2/3 or below to avoid damaging spinal cord
How does the intervertebral disc degenerate with age? What problems can this cause?
Nucleus pulposus dehydrates with age
Height of IV disc decreases
Load stresses on IV discs alter which leads to osteophytes
Increased stress on facet joints which leads to osteoarthritis
What type of joint are facet joints?
Synovial
What are the 4 types of slipped disc?
- Degeneration
- Prolapse
- Extrusion
- Sequestration
What is disc degeneration?
Chemical changes associated with ageing which causes the discs to dehydrate and bulge.
What is meant by disc prolapse?
Protrusion of the nucleus pulposus with slight impingement into the spinal canal (maintained)
What is disc extrusion?
Nucleus pulposus breaks through annulus fibrosis but remains within disc space
What is disc sequestration?
Nucleus pulposus breaks through annulus fibrosis and separates from the main body into the spinal canal
Where do disc prolapses most commonly occur?
L4/L5 or L5/S1
What are the 3 types of disc prolapse, which is most common?
Paracentrally - most common
Far lateral - at nerve root exit
Canal filling - compress cauda equina
What is sciatica?
Compression of the nerve roots which contribute to the sciatic nerve
Which nerve roots contribute to the sciatic nerve?
L4-S3
What is the most common cause of sciatica?
Prolapsed disc
What are the 3 types of sciatica, based on dermatomes?
L4, L5 and S1
What areas you expect to be affected by L4 sciatica?
Anterior thigh, anterior knee, medial shin
What areas you expect to be affected by L5 sciatica?
lateral thigh, lateral calf, dorsum of foot
What areas you expect to be affected by S1 sciatica?
Posterior thigh, posterior calf, sole of foot
Which nerve root will be compressed in an L4/L5 paracentral disc prolapse?
L5
Which nerve root will be compressed in an L4/L5 far lateral disc prolapse?
L4
What is cauda equina syndrome and what age group does it usually occur in?
Canal filling disc compressing the lumbar and sacral nerve roots
30-50 year olds
What will patients with cauda equina experience?
bilateral sciatica
perianal numbness
painless retention of urine
urinary/faecal incontinence
What patients are usually affected by lumbar canal stenosis and why?
Elderly patients- degenerative changes
Give 3 things that can cause lumbar canal stenosis.
- Disc bulge into canal
- Arthritis in facet joints -> osteophytes
- Ligamentum flavum stiffer, deposits and expansion
What is claudication?
Pain in the legs when walking
What is a common neurogenic cause of claudication?
lumbar canal stenosis
What is spondylolisthesis?
A slip forwards of the vertebrae above onto the vertebrae below
What happens in isthmic spondylolisthesis?
Pars articularis is thinner than usual so is at risk of fracture, often in teenage years.
Present as backpain predominantly.
Where is the pars articulates?
Between superior and inferior articular process’
How does the presentation of degenerative spondylolisthesis differ to isthmic spondylolisthesis?
Isthmic presents as backpain predominantly
Degenerative presents with claudication predominantly.
What happens in degenerative sponylolisthesis?
Arch still intact but develop stenosis via the same mechanism as lumbar canal stenosis.
What are the 3 types of spina bifida?
Occulta
Meningocele
Meningomyocele
What is the end of the spinal cord called?
Conus medullaris
What is scoliosis?
Abnormal lateral curvature of the spine
What is spina bifida?
Abnormality in development of the bones in the vertebral column
What happens in occulta spina bifida?
Laminae of lower lumber vertebrae and upper sacral vertebrae fail to fuse completely
What are the effects of occulta spina bifida?
No physical disability
Not usually detected
What happens in meningocele spina bifida?
Protrusion of the meninges through cleft in vertebrae.
Spinal fluid fills protrusion to give a cyst-like structure on childs back.
What are the potential effects of meningocele spina bifida?
May be residual damage to spinal cord, lower limb weakness, urinary or foetal incontinence
What happens in meningomyelocele spina bifida?
As well as meninges, spinal cord also herniates through vertebral cleft.
Significant spinal cord dysfunction.
What are the potential effects of meningomyelocele?
Learning difficulties
Paralysis/weakness of lower limbs
Incontinence
By what mechanism can meningomyelocele cause hydrocephalus?
Brainstem often pulled downward into spinal canal at base of the skull, obstructing flow of CSF.
