MSK session 8-9 Flashcards
How many vertebrae are there?
33 vertebrae 7 cervical 12 thoracic 5 lumbar 5 sacral 4 coccygeal
Which vertebrae are mobile?
Cervical and lumbar
What are the functions of the vertebral column?
- central bony pillar of the body
- supports the skull, pelvis, upper limbs, thoracic cage
- protection of the spinal cord and the cauda equina
- movement-highly flexible structure of bones, intervertebral discs and ligaments
- haemopoiesis - red marrow
Why do vertebral bodies increase in size inferiorly?
Compression forces increase
What are the movements of the lumbar spine?
Flexion and extension
Lateral flexion
Rotation
What seven processes are there on the vertical arch of a typical lumbar vertebra?
1 spinous process
2 transverse processes
2 superior articular processes
2 inferior articular processes
What does the lamina in the vertebral arch connect?
Lamina connects transverse process to spinous process
What does the pedicle connect in a vertebral process?
Transverse process to vertebral body
What is a laminectomy?
Removal of the spinous process and lamina to increase space for nerves
What type of joints are facet joints?
Synovial joints
How do spinal nerves emerge from the vertebral column?
Intervertebral foramina
What determines the amount of flexion and rotation permitted at different levels in the vertebral column?
Orientation of the inferior and superior articular processes at the facet joints
Where are intervertebral discs fund?
Between vertebral bodies in the vertebral column
Where are the two regions found in intervertebral discs?
Nucleus pulposus (central) Annulus fibrosus (peripheral)
Why does the height of intervertebral discs decrease with age?
Intervertebral discs are made up of water, collagen and proteoglycans.
As age increases, less proteoglycans are produced and replacement is slower. The size of the proteoglycan chains decrease. Proteoglycans attract water so the amount of water present decreases. The discs lose their height.
Describe the structure and function of the annulus fibrosis of the intervertebral disc.
Structure:
Made from lamellae of annular bands. Each lamella has regular collagen fibres arranged in a different orientation.
Function:
In any particular movement the vertebral column is in, some of the lamellae are tended and some are relaxed, providing a constant pressure to the nucleus pulposus.
Are the intervertebral discs or the vertebral body more effective at resisting compression?
Intervertebral disc- fibrocartilage with a high water content to withstand pressure and act as a shock absorber
What is the nucleus pulposus?
Remnant of the notochord
Made up of type 2 collagen
Changes in size with age
Centrally located in an infant, more posterior in an adult
Why is the correct technique of manual handling important?
Intervertebral discs are very strong in axial compression
What are the major ligaments of the vertebral column?
Which is strongest?
Anterior longitudinal ligament (stronger)
Posterior longitudinal ligament
Describe the location and function of the anterior longitudinal ligament.
Anterior tubercle of atlas to sacrum. United with the periosteum of vertebral bodies
Prevents hyperextension
Describe the location and function of the posterior longitudinal ligament.
Body of axis to sacral canal
Prevents hyperflexion
What is ligamentum flavum?
Made up of elastic fibres
Between laminae of adjacent vertebrae
Stretched during flexion of the spine - limits hyperflexion
Where are interspinous and supraspinous ligaments found?
-Interspinous ligaments
Between borders of adjacent spinous processes
Well developed only in lumbar region
-supraspinous ligaments
Between tips of adjacent spinous processes
Tight in flexion
What does the sacrum articulate with?
L5 superiorly
Ilium laterally
Coccyx inferiorly
Describe the curvatures of the different regions of the vertebral column
Cervical - lordosis Thoracic - kyphosis Lumbar - lordosis Sacral - kyphosis Coccyx - kyphosis
Describe the curvature of the vertebral column in the foetus.
Primary curvature (retained throughout life in thoracic, sacral, coccygeal regions)
C-shaped
Kyphosis
When does the lumbar spine lose its primary kyphosis?
Crawling
Lumbar lordosis develops when the child begins to stand up and walk (secondary curvature)
Where does the centre of gravity pass through the vertebral column?
C1 and C2
C7 and T1
T12 and L1
L5 and S1
What happens do the structure of the vertebral column in old age?
Senile kyphosis
What happens to the vertebral column during pregnancy?
Exaggeration of lumbar lordosis
Suggest a suitable vertebral level at which the needle for a lumbar puncture should be inserted. Explain your reasoning.
L3/4 or L4/L5
After the conus medullaris so only mobile spinal nerve roots are here rather than the spinal cord as this is where there is the least chance of neurological damage
State the structures through which the needle will pass in order from the skin to the subarachanoid space in a lumbar puncture
Skin Subcutaneous tissue Supraspinous ligament Interspinous ligament Ligamentum flavum Epidural fat and veins Dura mater Arachnoid mater Subarachnoid space
What is mechanical back pain?
Pain when the spine is loaded (while standing or sitting due to gravity)
Worse with exercise and relieved by rest (when lying down)
What is marginal osteophytosis?
As age increases, load stresses on the intervertebral disc alter.
There is reactive marginal osteophytosis adjacent to affected endplates (senile ankylosis/spondylosis deformans)
What does disc degeneration and marginal osteophytes is lead to?
- Increases stress on facet joints —> osteoarthritis (innervated by meningeal branch of spinal nerve - pain
- Decreased size of intervertebral foramen and compression of spinal nerves
What is disc degeneration?
Chemical changes associated with ageing cause discs to dehydrate and bulge
What is disc prolapse?
Protrusion of the nucleus pulposus with slight impingement into the spinal canal
What is disc extrusion?
Nucleus pulposus breaks through annulus fibrosus, but remains within the disc space
What is disc sequestration?
Nucleus purposes breaks through annulus fibrosis and separates from the main body of the disc in the spinal canal
What has happened when the symptoms of a slipped disc have resolved?
The disc material that had separated from the main body of the disc does not go back into the disc. The material is degenerated and this is an irreversible change to the vertebral disc.
What are the different types of disc prolapse?
Paracentral- within the vertebral canal
Far lateral - not in the vertebral canal, where the nerve root is exiting
Canal filling - compresses the entire cauda equina
What is sciatica?
Sciatica is compression of nerve roots which contribute to the sciatic nerve (L4 L5 S1 S2 S3)
NOT compression of the sciatic nerve
Loss of sensation over anterior thigh, anterior knee and medial shin due to a slipped disc. Which type of sciatica is this?
L4 sciatica
Loss of sensation over lateral thigh, lateral calf and dorsum of foot. Which type of sciatica is this?
L5 sciatica
Loss of sensation over posterior thigh, posterior calf, heel, sole of foot. Which type of sciatica is this?
S1 sciatica
There is a paracentral disc prolapse at the level L4/L5. Which type of sciatica will these lead to?
L5 sciatica
Does not compress exiting nerve as it has already left the spine. Affect nerve root below that
There is a far lateral disc prolapse at the level L4/L5. Which nerve root is compressed?
L4
What is cauda equina syndrome caused by?
Canal filling disc compressing the lumbar and sacral nerve roots
Where does the cauda equina begin?
L1/L2
What are the symptoms of cauda equina syndrome?
Bilateral sciatica
Painless retention of urine
Perianial numbness
Urine/faecal incontinence
What are the potential long term consequences of cauda equina syndrome if left untreated for > 48 hours?
Intermittent self catherisation
DRE
Sexual dysfunction
What is lumbar canal stenosis?
Narrowing of the vertebral canal due to: -disc bulge -facet joint osteoarthritis -ligamentum flavum hypertrophy Occurs in elderly
What is claudication?
Pain in legs when walking
Cause could be:
-neurogenic eg. Lumbar canal stenosis
-vascular
Leg pain with walking is medically known as claudication, and it can be caused by either arterial circulatory insufficiency (vascular claudication) or from spinal stenosis (neurogenic or pseudo-claudication). Leg pain from either condition will go away with rest, but with spinal stenosis the patient usually has to sit down for a few minutes to ease the leg and often low back pain, whereas leg pain from vascular claudication will go away if the patient simply stops walking.
For lumbar stenosis, flexing forward or sitting will open up the spinal canal by stretching the ligamentum flavum and will relieve the leg pain and other symptoms, but the symptoms will recur if the patient gets back into an upright posture. Numbness and tingling can accompany the pain, but true weakness is a rare symptom of spinal stenosis.
What is the pathophysiology of claudication due to lumbar canal stenosis?
As the nerves gradually get compressed, there is less scope for venous drainage
Venous engorgement- pooling of venous blood as drainage is blocked
Nerve roots become ischaemic
Pain going down legs in sciatic distribution
What is spondylolisthesis?
Slip forwards of the vertebra above on the vertebra below
What is the difference between dysplastic and isthmus spondylolisthesis?
Dysplastic - abnormality in the shape of the facet joints
Isthmic - defect in the pars interarticularis
What is the pars interarticularis?
Structure between superior and inferior articular processes
What is the clinical presentation of isthmic spondylolisthesis?
Back pain
L5 sciatica as vertebral arch is not intact
Present in adolescence or in adulthood once disc starts to age
How does degenerative spondolisthesis present?
Claudication as posterior arch is intact so they develop stenosis
Same presentation as lumbar canal stenosis
In the thoracic vertebrae, what do the transverse processes articulate with?
Ribs via costal facets
What is found at the junction of the lamina and the pedicles?
Articular processes
Superior and inferior
These articulate with the articular processes of the vertebrae above and below.
How many cervical vertebrae are there?
7
What are the distinguishing features of the cervical vertebrae?
- spinous process is bifurcated into two parts so is known as a bifid process (except C1 and C7)
- two transverse foramina - one in each transverse process. These conduct the vertebral arteries
- vertebral foramen is triangular in shape
How does the orientation of the superior and inferior articular facet of the cervical vertebrae affect movement here?
Superior articular facet faces upward and backward while inferior articular facet faces downward and forward.
Therefore, allows:
- flexion and extension
- lateral flexion
- rotation
What are the distinguishing features of thoracic vertebrae?
- demi-facets on sides of body
- spinous processes are slanted inferiorly and anteriorly - provides increased protection to the spinal cord
- vertebral foramen in circular
How does orientation of the articular processes influence the movement of the thoracic vertebrae?
Superior articular processes face posterolaterally
Inferior articular processes face inferomedially
This permits:
Rotation
Limits flexion
What is the filum terminale?
Delicate strand of fibrous tissue proceeding downward from the apex of the conus medullaris
What is the conus medullaris?
Tapered lower end of the spinal cord near L1 and L2 or occasionally lower
What is the cauda equina?
bundle of roots from the lumbar and sacral levels that branch off the bottom of the spinal cord like a horse’s tail
What is spina bifida?
Condition where the spine does not develop properly, leaving a gap in the spine.
It is a type of neural tube defect.
In spina bifida, arches of the vertebral bodies do not close properly. Sometimes there is only a gap in the bony arch, but at other times the spinal cord is also involved.
The damage to the spinal cord can lead to problems such as:
weakness or total paralysis of the legs
bowel incontinence and urinary incontinence
loss of skin sensation in the legs and around the bottom
What is the most common type of spina bifilda occulta?
Spina bifida occulta
Opening in the spine is very small and covered with skin
Means that the spinal cord and meninges can’t push out and there is no obvious bulge in the back.
It doesn’t usually cause any symptoms and most people are unaware they have it
What is kyphosis?
Excessive thoracic curvature, causing a hunchback deformity. Happens as you get older.
What is lordosis?
Excessive lumbar curvature, causing a swayback deformity
What is scoliosis?
Lateral curvature of the spine, usually of unknown cause
What is cervical spondylosis?
A decrease in the size of the intervertebral foramina, usually due to degeneration of the joints of the spine. The smaller size of the intervertebral foramina puts pressure on the exiting nerves, causing pain.
Degenerative osteoarthritis of intervertebral joints in cervical spine. Pressure on nerve roots leads to radiculopathy whereas pressure on the cord leads to myelopathy.
What does the atlas articulate with?
Occiput of the skull superiorly
C2 inferiorly
At which joint does 50% of total flexion and extension (nodding) occur?
Atlanta-occipital joint (C1 and skull)
At which joint does 50% of total rotation (shaking the head) occur?
Atlanto-axial joint (C1 and C2)
Which cervical vertebrae does not have a vertebral body and no spinous process?
Atlas
Which is the strongest cervical vertebra?
Axis (C2)
What are the distinguishable characteristics of axis?
- odontoid process or dens
- rugged lateral mass
- large spinous process
What prevents horizontal displacement of axis?
Dens and tranverse ligament
Which cervical vertebrae has the longest spinous process?
Seventh - the spinous process is not bifid
What is the nuchal ligament and what is it attached to?
Thickening of the supraspinous ligament
Attached to:
- external occipital protuberance
- spinous processes of all cervical vertebrae
- spinous process of C7
What are the functions of ligamentum nuchae?
- maintains curvature of cervical spine
- helps the cervical spine support the head
- major site of attachment of neck and trunk muscles eg. Trapezium, Rhomboids
What are the movements are the cervical spine?
Flexion and extension
Lateral flexion
Rotation
What are the distinguishable characteristics of the thoracic vertebrae?
- demi-facets on side of body for articulation with head of rib (T2-T8), whole facets T9-10
- costal facets on transverse processes for articulation with tubercle of rib
- vertebral foramen is small and circular
What does the anterior part of the spinal cord control?
Sensory and motor:
Light touch
Pinprick
Pain
What does the posterior part of the spinal cord control?
Vibration and proprioception
What do the central tracts of the spinal cord control?
Move the arms
What do the lateral tracts of the spinal cord control?
Move the legs
What is anterior cord syndrome?
Compression of anterior spinal cord
Loss of
Sensory and motor:
Light touch, pinprick, pain
What is central cord syndrome?
Compression of central tracts of the spinal cord
Loss of movement of arms
What is posterior cord syndrome?
Compression of posterior spinal cord
Loss of
Vibration and proprioception
What is neural level?
Last functioning level
What is radiculopathy?
Dermatomal sensory symptoms: paraesthesia, pain
Myotomal motor weakness
What is myelopathy?
Global weakness
Gait dysfunction
Loss of balance
Loss of bladder and bowel control
What is a Hangman’s fracture?
Caused by hyperextension of head
Axis fracture through the pars interarticularis
Unstable fracture
Forward displacement of C1 and body of C2 on C3
Leads to death most of the time
What is a peg fracture of the axis?
Caused by a blow to the back of the head or hyperextension
Transverse fracture of odontoid process of axis
How can a peg fracture be viewed?
Open mouth AP X-ray or MRI cervical spine
What is a Jefferson’s fracture?
Fracture of anterior and posterior arches of atlas (atlas fractures in at least 2 places)
Caused by axial load eg. Diving into the roof of a vehicle, falls from playground equipment
Typically causes pain but no neurological signs
May damage arteries at base of skull with secondary neurological sequelae eg. Ataxia, Horner’s syndrome
What is whiplash?
Hyperextension and hyperflexion
How would a cervical prolapsed intervertebral disc present?
Tear of the annulus fibrosis
Nucleus pulposus-migrates through the spinal canal
Wake up with pain
What will a patient complain of with a left sided C5/6 prolapsed disc?
C6 nerve is affected
Pain - biceps into thumb and index finger
Motor weakness - biceps and wrist extension
Sensory - numbness/ parasthesia thumb and index finger
How would a patient present with a C7/T1 prolapsed intervertebral disc?
C8 nerve root is affected
Pain - down to little and ring fingers
Motor weakness - long finger flexors
Sensory - numbness, parasthesia of little and ring fingers
What is cervical myelopathy?
Osteoarthritis of the cervical spine
Osteophytes
Thickening ligamentum flavour
Signal change in the spinal cord
Symptoms: Progressive Disorder Clumsiness Loss Fine motor movements Gait/ Balance disturbance Positive Hoffmanns and Babinski reflex Clonus Dysdiadhokokinesis
What will a patient complain of with a cervical myelopathy at C3/C4?
C3 is the neural level of injury
Pain - neck pain
Motor weakness - shoulder abduction
Sensory - numbness/parasthesia from shoulder down and feet
What will a patient complain of with a cervical myelopathy at C5/6?
Pain - neck pain
Motor weakness - elbow flexion, wrist movements, finger movements
Sensory - numbness, parasthesia from elbows down and feet
What is thoracic cord compression?
Fracture of the vertebra giving bony fragments in the canal or tumour developing in the canal compressing the spinal cord
What is the most common surgical cause of thoracic cord compression?
Fractures and tumours
How would a patient present with thoracic cord compression?
Pain - thoracic pain
Motor weakness - all muscles in legs
Sensory - numbness, pins and needles from umbillicus down, loss of sphincter control
If a tumour was present at T5 causing the thoracic cord to be compressed, how would a patient present?
Pain -High thoracic pain
Motor weakness - all muscles in legs and intercostal
Sensory - numbness, parasthesia just below nipples
Loss of sphincter control
