Mini symposium - spine Flashcards
What is the most common type of prolapse?
Postero-lateral disc prolapse
True or false: the interveterbal discs are avascular structures
True
Describe the structure of intervertebral discs
- Secondary cartilaginous joint
- Annulus fibrosus - Tough outer layer
- Nucleus pulposus - Gelatinous core
Which ligaments connect intervertebral discs with the vertebral bodies?
- Anterior longitudinal ligament
- Posterior longitudinal ligament
What is it about the annulus fibrosis structure that resists rotational movements and twisting i.e preventing disc protrusion?
The fibres of the annulus fibrosis run obliquely and alternately (at right angle) between layers
How does the normal ageing process affect the intervertebral discs?
- Decreased water content of discs over time
- Disc space narrowing
- Degenerative changes in the facet joints (OA) - aggravated by smoking and weight gain
What processes happen within the spinal canal as a result of degeneration?
- Tearing of annulus fibrosis and protrusion of the nucleus
- Nerve root compression by osteophytes
- Central spinal stenosis
- Abnormal movement - spondylolysis or spondylolisthesis
Nerve root pain
- Fairly common
- Limb pain is worse than back pain
- Referred to as radicular pain
- Most will settle, about 90% in 3 months settle without surgical intervention
- Physiotherapy can be helpful in both managing the pain and maintaining stability of the spine and muscle tone in the core muscles around the spine
- Strong analgesia - if severe radicular pain
- If patient has not improved after 12 weeks then they should be referred for imaging - MRI
What signs may a person show if they have a compressed or irritated nerve?
- Root tension signs - the most well known of these is the sciatic nerve stretch test. If the patient has a disc prolapse pressing on L5 or S1 nerve root – on lifting their leg they would develop increasing pain (+ve result)
- Root compression signs i.e lose reflexes or sensation
What are the different stages/names for disc problems?
- Bulge (generalised) – common, majority asymptomatic, relevance?
- Protrusion (annulus weakened but still intact)
- Extrusion (through annulus but in continuity)
- Sequestration (dessicated disc material free in canal)
In cervical disc prolapse which vertebrae are most commonly involved?
C5/C6
Thoracic disc prolapse
- Very rare - less than 1% of prolapses
- Most at T11/T12
- Central, posterolateral and lateral herniations
Lumbar disc prolapse
- Most common type of prolapses
- Majority are L4/5 (45%) followed by L5/S1 (40%) then L3/4 (10%)
- Most are posterolateral because the weakest point of the posterior longitudinal ligament is posterolaterally
- Central disc prolapse may give pain in both legs, or may be back pain only
Look
Need to know this
- EHL - extensor hallucis longus
Cauda equina syndrome
- Medical emergency!!
- Admission, urgent MRI, emergency operation within 48 hours of onset
- If not identified and treated rapidly the patient may be left with longterm disability
- Sacral nerve roots compression can result in permanent bladder and anal sphincter dysfunction and incontinence
What are some causes of cauda equina syndrome?
- Cental lumbar disc prolapse (commonest)
- Tumour
- Trauma (burst or Chance fracture) or spinal stenosis
- Infection i.e epidural abscess
- Iatrogrenic i.e spinal surgery or manipulation, spinal epidural injection
What is a Chance fracture?
Chance fracture is a type of vertebral fracture that results from excessive flexion of the spine.
How to treat lateral recess stenosis?
- Non-operative - may settle on its own
- Nerve root injection of steroid to diminish pain - done under x-ray, localised
- Epidural injection - steroid into epidural space - flows round multiple nerve roots - more general treatment
- Surgery is indicated - if patient is fit and symptoms persists - decompressing the nerve root
What is Spondylolisthesis?
Where one vertebra is translated on the other i.e it slips over the other vertebra.
The most common cause of this is degenerative changes, however, it can also be caused by things like infection, tumours etc
Treatment depends on symptoms and age:
- Most can be managed conservatively with lifestyle changes
- Surgery for persistent pain +/- nerve root entrapment
What is Spondylolysis?
Where there is a defect in the Pars interarticularis (small bone that connects the facet joints between transverse processes). This can cause the posterior elements of the spine to detach from the anterior elements.
Most common causes of spinal cord injuries
- Falls
- RTA
- Sport
- Knocked over/collision/lifting
- Trauma
- Sharp trauma/assault
Tetraplegia
- Complete or partial or total loss of use of all four limbs and the trunk
- Generally this is caused by injury in the cervical region
- Loss of motor/sensory function in the cervical segments of the spinal cord - use of hands is absent
X-ray shows C5 translated anteriorly on C6 - this patient would have respiratory failure due to loss of innervation of the diaphragm (damage to phrenic nerve C3-5)
After a period of spinal shock the patient would then have spasticity (increased tone) and hyperreflexia in all 4 limbs (after any complete spinal cord injury, for a period of time lasting 3-6 weeks, there are no reflex responses from neurons below the level of the injury. The neurons are in ‘shock’ from loss of UMN input, this shock gradually recedes and the reflex loops become increasingly hyperactive in the absence of inhibitory control from UNM’s)
Paraplegia
- Partial or total loss of use of the lower-limbs
- Impairment or loss of motor/sensory function in thoracic, lumbar or sacral segments of the spinal cord
- Upper limbs function well
- There may be associated injuries with this such as chest or abdominal injuries
- If injury is above L1 then get spasticity (spinal cord ends at L1 so anything below this is just nerve roots and affects Cauda equina which are essentially peripheral nerves)
- Bowel and bladder function affected
Central cord syndrome
- Most commonly affects elderly patients who have an arthritic neck
- When they fall and hit their head there is an injury to the central part of the cord
- Central part of the cord innervates upper limbs and more peripheral affects lower limbs
- So CCS causes weakness of arms > legs
- Perianal sensation & lower extremity power persevered
Cross-section of the spinal cord showing the representation of the cervical, thoracic, lumbar and sacral areas in the various spinal tracts
Anterior Cord syndrome
Causes:
- Hyperflexion injury
- Anterior compression fracture
- Vascular injuries to the spine i.e damaged anterior spinal artery causes ischaemia to the anterior cord
Damage to corticospinal tracts causes loss of motor function. Damage to spinothalamic tracts so loss of sensation and pain. Still have posterior collumns which give you fine touch and proprioception
Profound weakness
Brown-Sequard Syndrome
Caused by hemi-section of the cord
If you have an injury to one side of the spinal cord you will lose power on the same side but you will lose temperature sensation and pain on the opposite side below the level of the injury (as it crosses over at the same level it enters)
What is the most important aspect of management of a spinal cord lesion no matter if it is incomplete, complete or partial?
You don’t want any further damage to occur so prevention of a secondary insult is key.
Particularly important in patients with incomplete injuries as you can really make a difference to their function in the longterm by preventing it from becoming more severe. However, a complete injury doesn’t have any chance of recovery.
