22. Clinical conditions of the cervical and thoracic spine Flashcards
what is cervical spondylosis?
Cervical spondylosis is a chronic degenerative osteoarthritis affecting the
intervertebral joints in the cervical spine
what is the primary pathology of cervical spondylosis?
The primary pathology is usually age-related disc degeneration, which is followed by marginal osteophytosis (osteophyte formation adjacent to the end plates of the vertebral bodies) and facet joint osteoarthritis
why might cervical spondylosis lead to radiculopathy?
The resultant narrowing of the intervertebral foramina can put pressure on the spinal nerves leading to radiculopathy
What are the symptoms of radiculopathy?
Symptoms of radiculopathy include dermatomal sensory symptoms (e.g. paraesthesia, pain), and myotomal motor
weakness.
Why might cervical spondylosis lead to myelopathy?
If the degenerative process leads to narrowing of the spinal canal, this may instead put pressure on the spinal cord leading to myelopathy. This is a less common outcome than radiculopathy, and may manifest as global muscle weakness, gait dysfunction, loss of balance and/or loss of bowel and bladder control. These symptoms arise due to compression and dysfunction of the ascending and descending tracts within the spinal cord
What is the difference between radiculopathy and myelopathy?
Radiculopathy
• compression of nerve roots
• Osteophyte in the Foramen -
Myelopathy
• compression of spinal cord
• Osteophyte in the Vertebral Canal
• thickening ligamentum flavum
What is the triad for cervical spondylosis?
- Loss of Disc Height
- Osteophytes
- Facet Joint Osteoarthritis
What is the Jefferson’s fracture?
Jefferson’s fracture is a fracture of the anterior and posterior arches of the atlas
vertebra (C1). The fracture causes the C1 vertebra to burst open like a broken Polo® mint.
What can cause jefferson’s fracture?
The mechanism of injury is axial loading e.g. diving into shallow water,
impacting the head against the roof of a vehicle, or falling from playground
equipment. Patients may present to the Emergency Department supporting their
head with their hands.
Are there any neurological signs associated with Jefferson’s fracture?
Fortunately, the ‘bursting open’ of the bone fragments reduces the likelihood of impingement on the spinal cord. This fracture therefore typically causes pain but
no neurological signs.
Occasionally, however, there may be damage to the arteries at the base of the skull leading to secondary neurological sequelae e.g. ataxia, stroke, or Horner’s
syndrome.
What is horner’s syndrome?
Horner’s syndrome is damage to the sympathetic trunk leading to miosis
(decreased pupil size), partial ptosis (drooping eyelid), anhidrosis (decreased
sweating on the affected side of the face) and enophthalmos (sunken appearance
of the eyeball)
What is the Hangman’s fracture?
In a Hangman’s fracture, the axis vertebra (C2) is fractured through the pars
interarticularis (the region between the superior and inferior articular processes).
– Unstable fracture
– Forward displacement of C1 and C2 on C3
What can cause hangman’s fracture?
The mechanism of injury is usually
forcible hyperextension of the head on
the neck; historically by ‘hanging’ and
more recently in road traffic collisions.
Does hangman’s fractres damage the spinal cord?
This fracture is unstable and requires treatment. As with Jefferson’s fractures of the C1 vertebra, the fracture configuration tends to expand the spinal canal, thereby reducing the risk of an associated spinal cord injury
what can cause fractures of the odontoid process (peg fractures)?
• either flexion or extension injuries.
• The most commonly seen mechanism is an elderly patient with osteoporosis falling forwards and impacting their forehead on the pavement.
• This hyperextension injury of the cervical spine can result in a fracture of the
odontoid peg.
• Alternatively, sometimes these fractures are caused by a blow to the back of
the head resulting in a hyperflexion injury e.g. falling against a wall when
balance is compromised (such as when intoxicated)
How can fractures of the odontoid process be seen?
This fracture can be detected on an ‘open mouth’ AP X-ray or a CT of the
cervical spine (performed either as part of a ‘trauma series’ or during a CT scan
of the head).
What is whiplash injury and why are we very prone to it?
The head accounts for 7-10% of the total body weight. It is balanced on the cervical spine, which has high mobility and therefore low stability (as mobility and stability of joints are inversely related). The cervical spine is therefore very prone to whiplash
injury, which is a forceful hyperextension-hyperflexion injury of the cervical spine.
What is the classical mechanism of the whiplash injury?
The classical mechanism is the patient’s car being struck from the rear leading to an
acceleration-deceleration injury as follows:
At the time of impact, the vehicle suddenly accelerates forward. About 100
ms later, the patient’s trunk and shoulders follow, induced by a similar acceleration of the car seat.
The patient’s head, with no force acting on it, remains static in space. The result is forced extension of the neck, as the shoulders travel anteriorly under the head. With this extension, the inertia of the head is overcome, and the head then accelerates forward.
The neck then acts as a lever to increase forward acceleration of the head, forcing the neck into flexion.
After whiplash occurs, what secondary injuries may a patient complain of
- Arm pain and paraesthia (spinal nerve damage)
- Shoulder injuries (if holding the steering wheel)
- Lower back pain
- Chronic myofascial pain syndrome: secondary tissue response to disc or facet injury, chronic pain
How can whiplash result in the injury to the cervical cord
Sometimes whiplash can result in injury to the cervical cord, despite there being no accompanying bony fracture. The cervical spine is highly mobile and the
ligaments and capsule of the joints are weak and loose. Hence, there can be significant movement of the vertebrae (e.g. subluxation or dislocation) at the time of impact, with return to the normal anatomical position afterwards. Soft tissue swelling may be the only visible feature on imaging.
What is a protective factor against spinal cord injuries in the cervical spine
A protective factor against spinal cord injury is that the vertebral foramen is large relative to the diameter of the cord. The normal diameter of the cervical spinal
canal is 17-18 mm. The average diameter of the spinal cord in the cervical region is 10mm.
In which age group does cervical inter vertebral disc prolapse mainly occur?
Cervical disc prolapse with associated compression of nerve roots or spinal cord most commonly develops in the 30 to 50 year-old age group.
describe the mechanism of disc herniation
• The mechanism of disc herniation is similar to that seen in the lumbar spine in that a tear develops in the annulus fibrosus of the disc, and the nucleus pulposus protrudes from the disc, with impingement onto an adjacent nerve root or the spinal cord
• [Note that in the cervical region, it is the spinal cord, not the cauda equina that is compressed].
• Sometimes sequestration occurs in which an extruded segment of nucleus pulposus separates from the main body of the disc and enters the spinal canal where it is ultimately resorbed over a period of weeks, with resolution of symptoms.
• Cervical intervertebral disc prolapse may be spontaneous in origin or may be related
to trauma and neck injury.
Why might even a small disc herniation cause significant pain?
The discs in the cervical spine are not very large. However, there is also little space available for the exiting nerves (unlike in the lumbar spine) so even a small cervical disc herniation may impinge on the nerve and cause significant pain.
