Cervical spine fractures & injuries.
The cervical spine is very often affected by injuries.
The spine is the supporting column of the human body and transfers forces and loads from the head and trunk to the pelvis and legs. For it to perform this function, the spine is positioned almost centrally in the body and has powerful muscles covering it to the rear side. With its frontmost segments, the vertebral bodies, the spine is embedded in the soft tissue of the neck, as well as in the chest and abdominal cavities. The spinal cord runs through a bony canal formed from the vertebral bodies at the front and the vertebral arches at the back. This ends at about the level of the transition between the thoracic and lumbar spine and there passes into the network of nerves supplying the legs.
While thoracic and lumbar spine are designed for stability and high forces, the cervical spine is made for mobility. For this reason, the cervical spine is very often affected by injuries such as spinal fractures.
Fractures & traumatic instability of the cervical spine.
As the structure connecting the head and trunk, the cervical spine has a particular functional significance. The cervical spine not only supports the head, but also carries all nerve tracts running from the head to the body, as well as the nerve tracts carrying signals from the body to the brain. Therefore, an injury to the cervical spine may not just affect the mobility and stability of the head and neck but may also cause direct damage to important nerve tracts. This may in turn have effects on the entire body. There are two transitional zones in the cervical spine area, the transition from the head to the upper cervical spine and the transition from the lower cervical spine to the thoracic spine. Injuries are more common in these regions because they represent a transition from a mobile segment of the spine to a more rigid spinal segment. In infants and the elderly in particular, injuries in the upper cervical spine area are more common.
Symptoms & causes of cervical spine fractures.
Information. Anatomy & injuries of the cervical spine
Structure of the cervical spine.
The cervical spine consists of a total of seven vertebrae and is divided into the upper and lower cervical spine. The reason lies in the different shapes of the vertebrae and the possible injuries resulting from this. For example, the first cervical vertebra is ring-shaped, while the second cervical vertebra already has a vertebral body to the front. This has a pin-like protrusion which extends into the ring of the first cervical vertebra and works with ligaments and joint capsules to prevent shifting. The two upper cervical vertebrae are also attached to the base of the skull with joints and strong ligaments, as a result of which a part of the back of the skull is also considered to belong to the upper cervical spine. By contrast, cervical vertebrae three to seven are uniform in shape. In these vertebrae, the load bearing part, or vertebral body, is located to the front, with a bony arch protruding to the rear which encloses the spinal canal and protects the spinal cord from mechanical impacts. There are discs between the vertebral bodies. These act as shock absorbers and are able to distribute shocks evenly across the entire surface of the vertebral body. The vertebrae are also connected by powerful ligaments, resulting in what is overall a very strong but nonetheless highly mobile functional unit.
When do cervical spine fractures occur?
However, if the cervical spine is unexpectedly exposed to strong forces during an accident, it is possible for individual connections to tear or for fractures to occur in the bone. As the bones and ligaments get weaker with age, it will take less force to cause injuries in the cervical spine.
Types of cervical spine injury.
A distinction is drawn between different types of impact:
- Type A = Compression mechanisms
- Type B = Injury resulting from the cervical spine being bent too far in one direction
- TypeC = Injury or injuries caused by the head and neck being forcefully twisted
In most cases, it is possible to determine the type of impact from the pattern of injuries. For example, major compression will in most cases cause fractures in the area of the vertebral body, which can even be as severe as fragmenting.
Mechanisms causing the cervical spine to be bent too far in one direction frequently result in torn discs and ligaments. The feared dislocation of the cervical spine will in most cases result from forceful twisting movements.
Types of cervical spine injury in older people.
In the elderly, what are known as "trivial mechanisms", such as banging the chin on the sink or falling forwards, are often sufficient to cause fractures in the cervical spine, which is in most cases somewhat stiff and weakened in their bone structure. The most common fractures in these cases include what is known as a dens fracture, which is a break in the tooth-like protrusion on the second cervical vertebra.
Frequency of injuries to the cervical spine.
Only considerable traumatic impacts will cause a fractured spine in a person with a healthy bone structure or tears in the discs and ligaments located between the vertebral bodies. Not counting sprains and strains, approximately 6,000 severe spinal injuries occur in Germany each year. The comparatively small proportion of spinal injuries (0.5 - 1 % of all human injuries), contrasts to a certain extent with the significance of the injury and the consequences of the victim themselves.
Causes. How cervical spine injuries develop
How do injuries to the cervical spine occur?
Babies and infants sometime suffer from cervical spine injuries as a result of severe traffic accidents with rear or frontal collisions. This is caused by the size of the head being disproportionate to the still weakly developed neck muscles. The shear forces arising from the accident may therefore cause severe upper cervical spine injury in particular.
Causes of cervical spine injuries in youths and adults.
- Motorbike and mountain bike accidents
- Diving head first into unfamiliar, shallow water
- Contact sport accidents (ice hockey, wrestling, American football) and horse riding accidents
- In older people, minor trauma, such as a fall, is often enough to cause injuries to the cervical spine.
Symptoms. Signs of cervical spine fractures
Cervical spine injuries and quadriplegia.
Approximately every fifth severe cervical spine injury is associated with paralysis or at least a loss of sensation. This is the result of compression or distortion damaging the spinal cord and the exiting nerves. Compression damage can be a result of vertebrae being traumatically displaced in relation to each other, fragments of bone shooting into the spinal canal and bleeding in the spinal cord or the spinal column.
Typical deficits occur depending on the level damaged by these injuries.
- Injuries to the upper cervical spine region can result in immediate respiratory and circulatory arrest as the vitally important centres for breathing and circulation are found in the near vicinity. These injuries often cause death unless resuscitation is started straight away.
- Injury to the spinal cord above the fourth cervical vertebra can also cause major problems with breathing as the nerves for the diaphragm exit the vertebral column at this point.
- Loss of nerve function can present as so-called complete or incomplete quadriplegia. A complete quadriplegic syndrome at the cervical spine is not only characterised by the complete loss of function in the arms and legs, it is also characterised by the complete loss of sensation below the injured spinal level. This is usually associated with disturbances to the autonomic nervous system which can affect the regulation of the circulation, bowel, and the emptying of bladder and bowel.
What are the symptoms?
In the case of cervical spine injuries involving neural deficits, these deficits will initially be the most obvious symptoms. If conscious, victims will report a loss of sensation or an inability to move their arms and legs; these are clear indicators of the segment of the spine which has been affected by the injury.
If there are no neural deficits, the following symptoms will be reported in most cases:
- Pain in the cervical spine and in the neck when inactive and/or during movement
- A poorly positioned or tilted head
- Patients feeling that they can no longer hold their head up on their own