Clinical spine Flashcards
How to identify spine sections on X ray
for AP: Owls face Eyes of owls = pedicles Owls beak = spinous process Vertebral body = head Transverse processes stick out to side
Imaging for spine:
X-ray (AP and Lateral)
CT
MRI for ligaments
Common to least common lumbar pathology
Mechanical back pain Prolapsed intervertebral disc Spinal Stenosis Spondylolisthesis Spinal infection/tumour
Causes of mechanical back pain
Bad posture (can be from poorly designed seating)
Little exercise
Obesity
Incorrect manual handling
Mechanical back pain characterised by
Pain when the spine is loaded
Worse with exercise
Relieved by rest
What happens as spine ages?
Loss of height of disc = disc bulging
Osteophytes (syndesmophytes from marginal osteophytosis)
Facet joint OA
What occurs when facet joints get OA?
PAIN (innervated by meningeal branch of spinal nerves)
Ultimate result of decreased disc height, OA in facet joints?
Intervertebral foramina decrease in size = compression of spinal nerves
Pain caused by compression of spinal nerve
Radicular / Nerve pain
What occurs during herniation of disc?
‘slipped disc’
Nucleus pulposus protrudes and compresses spinal nerve
4 stages of disc herniation
Disc degeneration
Prolapse
Extrusion
Sequestration
Disc degeneration
ageing = chemical changes
discs dehydrate and bulge
Prolapse
Protrusion of nucleus pulposus slightly into spinal canal
*Still contained within annulus fibrosus
Extrusion
Nucleus pulposus breaks through annulus fibrosus but still contained within disc space
Sequestration
Nucleus pulposus seperates from main body of disc and enters spinal canal
Most common sites for slipped disc
L4/5
L5/S1
(from mechanical loading)
When are nerve roots most vulnerable?
Crossing intervertebral disc paracentrally
When they exit spinal canal via intervertebral foramina
Paracentral prolapse
most common (96%)
Posterolaterally (PLL prevents straight posterior)
TRAVERSING nerve root affected
Other prolapse
Far lateral (2%) Central (2%) towards spinal cord (risk of cauda equina syndrome)
Exiting root
Nerve that exits spinal canal at same level as disc
Traversing root
Nerve root that emerges level below the disc
Affected in paracentral prolapse
If paracentral herniation occured at L4/5 which root would be affected?
L5 as its traversing
What is sciatica?
Pain caused by irritation or compression to one of the spinal nerves contributing to the sciatic nerve
(L4 L5 S1 S2 S3)
Where is pain usually experienced in sciatica?
Back and buttock
radiates to dermatome supplied by that root (follows path)
L4 sciatica pain
Anterior thigh, anterior knee and medial leg
L5 sciatica pain
Lateral thigh, lateral leg, dorsum of foot
S1 sciatica pain
Posterior thigh, posterior leg, heel, sole of foot
Where is parasthesia experienced in sciatica?
ONLY in affected dermatome (not full path)
Cauda equina syndrome possibly
Prolapsed intervertebral disc filling spinal canal
Other causes Cauda equina syndrome
Tumours Infection/abscess Spinal stenosis (from OA) Fracture in vertebrae Spinal haemorrhage Late stage Ankylosing spondylitis
RED FLAG for Cauda equina
Bilateral Sciatica Perianal numbness Painless retention of urine Urinary/faecal incontinence Erectile dysfunction
Treatment Cauda equina syndrome
Surgical decompression urgently
(otherwise: chronic neuropathic pain, self catheterisation, faecal incontinence, loss of sensation/weakness in lower limb = WHEELCHAIR)
Spinal canal stenosis
Abnormal narrowing of spinal canal compresses spinal cord or nerve roots
Who and why spinal stenosis?
Elderly
Disc prolapse, Facet OA, Ligamentum flavum hypertrophy
Other not so common causes of spinal stenosis
Compression fractures of vertebral bodies
Spondylolisthesis
Trauma
Symptoms of spinal stenosis
Pain when standing Discomfort in shoulder/arm/hand (cervical) or lower limb (lumbar) Numbness at and below stenosis Weakness at and below Neurogenic claudication
Neurogenic claudication - what does it feel like
symptom
pain/pins and needles in the legs after prolonged standing/walking
radiating sciatica distribution
Claudication meaning
Latin for limb
cramping/weakness in legs = limp
Neurogenic claudication cause
Compression of spinal nerves as they emerge from lumbosacral spinal cord/cauda equina
What happens to neurogenic claudicated nerved during exercise?
Venous engorgement
Reduced arterial inflow
Arterial ischaemia = pain/paraesthesia
How is neuroclaudication relieved?
Rest
Change in position
Flexion of spine (open canal)
Spondylolisthesis
Anterior displacement of vertebrae above relative to vertebrae below
How is spondylolisthesis spotted on x ray?
Scotty dog outline on oblique xray of spine
If dog wearing collar = stress fracture (spondylolysis)
If dogs head detatched from body = spondylolisthesis
Spondylolysis
Fracture in pars interarticularis
between superior and inferior articulating processes
Lumbar puncture
Withdrawal of fluid from subarachnoid space of lumbar cistern (filled with CSF)
Patient position lumbar puncture
Patient on side
back and hips flexed (knees to chest)
=Spreads apart vertebral lamina and spinous processes and stretches ligamentum flavum
Where is lumbar puncture needle inserted?
Midline between spinous processes of L3 and L4
or L4 and L5
How can this lumbar location be located?
Plane transecting highest points of iliac crest (supracristal plane)
no danger damaging spinal cord here
What happens during lumbar puncture?
Passes 4-6cm in adults (through skin and subcutaneous fat) needle 'pops' through ligamentum flavum epidural fat and veins punctures dura mater punctures arachnoid mater enters lumbar cistern
Layers of mater
Epidural space Dura mater Arachnoid mater CSF Pia mater at base
