Lecture 4 - Spinal conditions Flashcards
Mechanical back pain
Pain when spine is loaded
Worst with exercise and better with rest.
Risk factors for mechanical back pain
Obesity Poor posture Sedentary lifestyle Weak core muscles Incorrect manual handling
Marginal osteophytosis
Bony spurs (syndesmophytes) develop adjacent to the endplates of the vertebral discs
Due to nucleus pulposus dehydration with age
Therefore decrease in height of disc, bulging and changes to load stresses on joints.
Increased load on facet joints - osteoarthritic changes
Why does arthritis cause pain
Facets supplies by meningeal branch of spinal nerve
Decreased size of intervertebral foramen therefore compression of spinal nerves
Causes radicular/nerve pain
Slipped disc
Herniation of an intervertebral disc compresses spinal nerve
4 stages of disc herniation
- Disc degeneration
- Prolapse
- Extrusion
- Sequestration
Disc degeneration
Chemical changes associated with ageing causing the nucleus pulposus to dehydrate and bulge
Prolapse
Protrusion of the nucleus pulposus occurs causing slight impingement into the spinal canal
Nucleus pulposus still contained within annulus fibrosus
Extrusion
Nucleus pulposus breaks through the nucleus fibrosus but still contained in disc space
Sequestration
The nucleus pulposus separates from the main body of the disc and enters the spinal canal
Common sites for slipped disc
L4/L5
L5/S1
Where are the nerve roots most susceptible to damage?
- When leaving the spinal canal in the neural foramen laterally
- Where they cross the intervertebral disc paracentrally
What is the most common direction for nucleus pulposus herniation?
Posterolaterally - lateral to the posterior longitudinal ligament
Therefore compresses spinal nerve root within the intervertebral foramen
Paracentral prolapse
Herniation of the nucleus pulposus posterolaterally which compresses the spinal nerve in the intervertebral foramen
96% of cases
What is the risk of central herniation?
Cauda equina syndrome
What nerve is at risk of compression in a far lateral herniation
Exiting nerve root - emerges at the same level as the intervertebral disc
What nerve is at risk in a posterolateral herniation
Traversing nerve root- emerges at a level below the intervertebral disc
In a paracentral herniation of the L4/L5 disc, what nerve root is compressed?
L5
Sciatica
Pain caused by irritation or compression of one or more of the sciatic nerve roots (L4 - S3)
Pain in the back and buttocks and radiates to the dermatome supplied by the affected nerve root.
Causes of sciatica
Marginal osteophytosis
Slipped disc
L4 Sciatica distribution of pain
Anterior thigh
Anterior Knee
Medial Leg
L5 Sciatica distribution of pain
Lateral thigh
Lateral leg
Dorsum of foot
S1 Sciatica distribution of pain
Posterior thigh
Posterior leg
Heel
Sole of foot
Nerve compression in sciatica
Only causes paraesthesia in the affected dermatome
Cause of cauda equina syndrome
- Centrally prolapsed disc - canal filling disc
- Tumours of the vertebral column or memninges
- Spinal infection
- Absesses
- Spinal stenosis secondary to arthritis
- Vertebral fracture
- Spinal haemorrhage
- Late-stage ankylosing spondylitis
Compresses the lumbar or sacral nerve roots within the spinal canal
5 Red flag signs of cauda equina
- Bilateral sciatica
- Perianal numbness
- Urinary/ faecal incontinence
- Painless urine retention
- Erectile dysfunction
How to treat cauda equina syndrome?
Emergency surgical decompression with 48 hours of teh onset of sphincter symptoms
(otherwise poor prognosis)
Spinal canal stenosis
Abnormal narrowing of the spinal canal that compresses the spinal cord or the nerve roots
Causes of spinal canal stenosis
Combination of:
- Disc bulging
- Facet joint osteoarthritis
- Ligamentum flavum hypertrophy
Also get:
- Compression fractures of the vertebral bodies
- Spondylolisthesis
- Trauma
What is the most common spinal cord stenosis and how does it present?
Lumbar stenosis
Discomfort while standing Discomfort/pain in the lower limb Bilateral symptoms Numbness and weakness at or below level of stenosis Neurogenic claudication
Neurogenic claudication
Pain or pins and needles in legs on prolonged standing and on walking
Radiating in a sciatic distribution
Causes of neurogenic claudication
Compression of spinal nerves as they emerge from the lumbosacral spinal cord
Venous engorgement of the nerve roots during exercise
Reduced arterial blood flow- transient ischaemia
What relieves neurogenic claudication?
Rest
Flexion of spine
Change in position
Spondylolisthesis
Anterior displacement of the vertebrae above
Causes of spondylolisthesis
Congenital - unstable facet joints Degenerative - arthritis and joint remodelling Trauma Pathological - infection/malignancy Iatrogenic
Lumbar puncture (L3/L4)
Withdrawal of fluid from the subarachnoid space of the lumbar cistern
Patient lying on the side with back and hips flexed
L3/L4 located by identifying the highest point of iliac crest
