4 - Lumbar Spine and Disorders Flashcards
What are the mobile and immobile parts of the spine?
Mobile = Lumbar and Cervical
Immobile = Thoracic
What are the functions of the vertebral column?
- Protection
- Haemopoiesis
- Support
- Movement
What do the lamina and pedicle connect?
- Lamina connects transverse process to spinous
- Pedicle connects transverse to body
What are the joints like between each vertebrae?
Facet/Zygapophyseal Joints
Lined with hyaline cartilage and synovial joints
Interlocking design prevents antero-posterior displacement
What movement occurs in each region and why?
Cervical: Flexion, extension, lateral flexion, rotation
Thoracic: Only lateral flexion and rotation
Lumbar: Mainly flexion and extension some limited lateral flexion and extension from L5 as facet faces anteriorly
What other joints are there in the spine apart from facet?
Secondary Cartilaginous (Symphyses): Intervertebral discs
Fibrous: Sacro-iliac joint
What is the structure of the intervertebral discs?
- Contains water and proteoglycans too
- Discs lose height with day and age
- Slightly wedge shape posteriorly
- Avascular and aneural so all diffusion and osmosis
- Nucleus goes from central to slightly posterior as get older and has high oncotic pressure
Label this diagram with the main ligaments of the spine.
What do each of the spinal ligaments do?
Posterior Longitudinal: prevents hyperflexion from C2 to S canal. Reinforces annulus fibrosus centrally
Anterior Longitudinal: stronger than pos and prevents hyperextension. C1 to Sacrum. Blends with periosteum but loosely attached and slides over discs
Ligamentum Flavum: Yellow between laminae and adjacent vertebrae. High elastin. Stretched during flexion
Interspinous: Weak fibrous tissue between spinous processes, well developed in lumbur area, restrict hyperflexion
Supraspinous: Tips of spinous processes, lax in extension, prevent hyperflexion and mechanical stability
How do intervertebral discs mainly prolapse?
Paracentrally as posterior longitudinal ligament supporting annulus fibrosus
How should you lift heavy weights and why?
Close to you with straightback so force picking up is equal to force on back
Where does force transmission occur in the spine?
Young: 80% vertebral body, 20% facet joints
Old: Disc dehydration so 35% in facet joints, leading to osteoarthritic changes
Describe the structure of the sacral and coccygeal spine and discuss what it articulates with.
Coccyx is remnant of a tail
Where does the central canal end?
Fourth sacral at the sacral hiatus
What nerves originate from the cauda equina?
- 2nd to 5th lumbar nerves
- 5 sacral nerves
- 1 coccygeal nerve
All innervate the pelvic organs and lower limbs
What is the dural sac?
The proximal parts of the cauda equina are enclosed in tough fibrous sac that terminates at around S2
How do nerve fibres leave from the sacral vertebrae?
Posterior sacral foramina
What is the filum terminale?
Continuation of the pia mater from the conus medullaris to the first segment of the coccyx. Approx 20cm and gives longitudinal support to spinal cord
What are the curvatures of the vertebral column?
What happens to the curvature of the spine with age and in pregnancy?
- Senile Kyphosis due to loss of disc height and osteoporitic fractures
- Pregnancy leading to exaggerated lumbar lordosis to reestablish centre of gravity
Where are the weak points of the vertebral column and why are they weak?
- C1 and C2
- C7 and T2
- T12 and L1
- L5 and S1
Centre of gravity passes through these so curves needed. Junctions are from mobile to stiff so weak spots.
Allows transmission of weight into lower limbs with curves
Label the parts of this spine.
Can assess disc height and some ligaments with this
Label this MRI of the spine.
Can see ligaments and discs better
Label the ligaments of this spinal MRI
What is mechanical back pain?
Pain when the spine is loaded that worsens with exercise and relived by rest. Intermittent and can be brought on by littlest of activities
Risks: obesity, sedentary, poor posture, deconditioning of core muscles, incorrect manual handling, poor mental health stresses can feed into pain
What are age degenerative changes of the vertebral column?
What condition is this x-ray displaying?
Syndesmophytes leading to marginal osteophytosis
What are the stages of a disc slipping (herniate)?
- Most common at L4/5 and L5/S1 due to mechanical loading
- Will affect nerve below as nerve passes through superior intevertebral disc, e.g L4/5 herniation will affect L5
Where are nerve roots most vulnerable?
- Where they cross the intevertebral disc (paracentrally)
- Where they leave the spinal canal (laterally)
Where are the spinal roots?
White dot on left, other side cannot be seen due to herniation
What are the different types of herniation and what can they lead to?
- Paracentral: traversing nerve root vulnerable
- Far Lateral: exiting nerve root vulnerable
- Central: cauda equina syndrome
What is sciatica?
- Pain caused by irritation or compression of one or more of the nerve roots that contribute to the sciatic nerve (L4, L5, S1, S2, S3)
- Pain from lowe back/buttock to dermatome. Can be due to things like slipped disc and marginal osteophytosis
Why would irritation occur with a slipped disc?
Release of nucleus pulposus which has a low pH
Where is the typical distribution of pain in L4, L5 and S1 sciatica?
What is cauda-equina syndrome caused by?
Can occur secondary due to canal filling disc prolapse that compresses lumbar and sacral roots. Also occurs due to:
- Tumours in meninges and vertebrae
- Infection/abscess
- Spinal stenosis
- Vertebral fracture
- Spinal haemorraghe
What are the red flag symptoms of cauda equina and how do you treat it?
Surgical decompression within 48 hours or wheelchair bound, impotent, self-catheterisation, fecal incontinence
What is spinal canal stenosis?
Symptoms:
- Discomfort standing
- Discomfort/pain in shoulder, arm, hand or lower limb
- Numbness + Weakness at or below level of stenosis
- Neurogenic claudication
70% stay same, 15% worse, 15% better
What is neurogenic claudication?
- Pain and/or pins and needles in legs on prolonged standing and walking, radiating in sciatic distribution
- Compressiom of spinal nerves as they arise from lumbosacral spinal cord
- Anything that favours flexion is tolerated as increases spinal canal space. Relieved by rest
What is spondylolisthesis?
- Anterior displacement of the vertebra above on the vertebra below
- Can be asymptomatic, neurogenic claudication, sciatica, lower back pain
How do you treat spondylolisthesis?
Initially NSAIDs, activity modification etc depending on the grade
How do you take a lumbur puncture?
Withdrawal of fluid from subarachnoidal space of lumbar cistern for diagnostic testing.
Patient lying on side, hips flexed, flexion of vertebral column to spread open spinous processes and stretch ligamentum flavum.
Lumbur puncture needle L3/L4 or L4/L5 by finding supracristal plane where L4 spinous processes cross
Pops through ligamentum flavum, then dura, then arachnoid to enter lumbar cistern
What is spondylolysis?
Separation of the articulating facets due to a pars articularis fracture
