Cervical Spine Surgery
The cervical spine, or neck, begins at the base of the skull and through a series of seven vertebral segments connects to the thoracic, or chest, region of the spine.
The first cervical vertebra is unique, as it is a ring—called the atlas—that rotates around part of the second vertebra—the axis. This construct provides most of the rotation for the neck and head.
The seven vertebrae of the cervical spine are connected in the back by paired facet joints, which allow for forward and backward extensions, as well as twisting movements. These facet joints can wear down over time and lead to cervical spinal stenosis or osteoarthritis. In between the vertebrae are six cervical discs that act as shock absorbers and allow flexibility and movement of the neck. These discs may herniate or degenerate, either through wear and tear over time or from an injury.
The cervical spine has eight cervical nerves, C1 through C8, that branch off of the spinal cord and exit through the neural foramen in the back of the spine. Each cervical nerve is named for the vertebra below it. For example, the nerve root that runs between the C5 and C6 is the C6 nerve. A number of cervical spine conditions may inflame or irritate these nerve roots, resulting in pain that radiates down the arms and possibly fingers, known as cervical radiculopathy.
The cervical spine includes an intricate network of muscles, tendons, and ligaments that provide support and movement. These tissues can spasm or become strained, which is a common cause of neck pain and stiffness. The spinal cord travels from the base of the skull through the cervical spine. Any cervical condition that encroaches on the spinal canal can affect the spinal cord and cause neurological symptoms, such as muscle weakness or numbness in the arms or legs.
Any of these cervical spine structures can degenerate over time or become injured, resulting in a variety of possible conditions and symptoms.
Neck anatomy is a well-engineered structure of bones, nerves, muscles, ligaments and tendons. The cervical spine (neck) is delicate – housing the spinal cord that sends messages from the brain to control all aspects of the body – while also remarkably flexible, allowing movement in all directions, and strong.
The neck begins at the base of the skull and through a series of seven vertebral segments connects to the thoracic spine (the upper back). With its complex and intricate construct, and the many stresses and force that can be placed on it through a trauma or even just daily activities, the cervical spine is at risk for developing a number of painful conditions, such as:
- Cervical degenerative disc disease
- Cervical herniated disc
- Cervical stenosis
- Cervical osteoarthritis
The Cervical Spine: Roles and Functionalities
The cervical spine maintains several crucial roles, including:
- Housing and protecting the spinal cord. A bundle of nerves that extends from the brain and runs through the cervical spine and thoracic spine (upper and middle back) prior to ending just before the lumbar spine (lower back), the spinal cord relays messages from the brain to the rest of the body.
- Supporting the head and its movement. The cervical spine literally shoulders a big load, as the head weighs on average between 10 and 13 pounds. In addition to supporting the head, the cervical spine allows for the head’s flexibility, including rotational, flexion/extension and lateral bending motions.
- Facilitating flow of blood to the brain. Vertebral openings (vertebral foramen) in the cervical spine provide a passageway for vertebral arteries to pass and ensure proper blood flow to the brain. These openings are present only in the vertebrae of the cervical spine.
The cervical vertebrae are composed of cylindrical bones (vertebral bodies) that lie in front of the spinal cord, and work with the muscles, joints, ligaments and tendons to provide support, structure and stabilization to the neck.
The first cervical vertebra is unique in that it is a ring that rotates around the second vertebral body (the odontoid). The cervical vertebrae closest to the skull are the smallest. All of the cervical vertebrae are smallerthan the vertebrae in the thoracic spine (upper back) and the lumbar spine (lower back).
Cervical Vertebrae Roles and Responsibilities
Stacked on top of each other with a cervical disc in between them, the cervical vertebrae provide strength and structure to the cervical spine and support the head. The cervical vertebrae also provide for structure and control of certain types of movement in the neck (with the movement described in terms of the two vertebral bodies that are connected), including:
- Rotation (moving the head from side to side). Most rotation of the neck takes place in the first two segments of the cervical spine, specifically the atlas (C1) and the axis (C2).
- Flexion (moving the head forward) and extension (moving the head backward). Most flexion and extension movements in the neck are controlled by the C5-C6 and C6-C7 segments of the spine. Unlike the first two cervical vertebrae, the remaining five cervical vertebrae, C3 through C7, are constructed more similarly to the rest of the spine, with three joints making up each vertebral segment (a disc in the front and two facets joints in the back)
Cervical Pain from Degeneration and Injury
Cervical Degeneration: Bone Spurs and Cervical Osteoarthritis
A bone spur (medically known as an osteophyte) describes an enlargement of the facet joints, the small stabilizing joints that are located between and behind the adjacent cervical vertebrae. Bone spurs are smooth structures that can grow on the bones and tend to occur in adults over 60 years of age.
Patients with cervical bone spurs may or may not have symptoms, which could include neck pain and/or referred pain and weakness in the arms and the legs. For example, patients with cervical bone spurs may experience dull neck pain that occurs when standing. In some instances, the pain may be referred to the shoulders or prompt headaches.
However, it must be emphasized that the presence of bone spurs in and of themselves does not necessarily mean this is what is generating a patient’s pain. Most bones spurs are simply radiographic findings indicating a patient has degeneration in the neck.
Bone spurs may form as the result of cervical osteoarthritis, a condition marked by degeneration and breakdown of the cartilage between the facet joints in the cervical spine. With cervical osteoarthritis (also known as cervical arthritis), different symptoms may occur, such as pain that:
- Refers to the shoulder or between the shoulder blades
- Feels worse at certain times of the day (early in the morning, late at night)
- Calms with rest.
Rarely requiring surgery (such as when there is a vertebral fracture in the neck), cervical osteoarthritis is typically treated via rest, pain medications, chiropractic and/or traction.
There are six cervical discs and 23 total discs in the entire spinal column. Each cervical disc rests between the cervical vertebrae, acts as a shock absorber in the cervical spine and allows the neck to handle much stress. Composed of collagen and ligaments, the cervical discs also hold the cervical vertebrae together and allow for flexibility and different movements of the neck.
Cervical Disc Construction
Each cervical disc is made up of a tough exterior (annulus fibrosus) and a soft, jelly interior (nucleus pulposus), with the circular, outer core comprised of collagen fibers that surround the inner core and distribute pressure and force on the structure.
The nucleus pulposus is a loose, fibrous network suspended in mucoprotein gel that is sealed by the annulus fibrosus and needs to be well-hydrated in order to maintain its strength and softness, and serve as the major carrier of the body’s axial load.
With age, the cervical discs lose water, stiffen and become less flexible in adjusting to compression. Such degenerative changes may result in the inner core of the cervical disc extruding through the outer core and coming in contact with the spinal nerve root (what is known as a herniated cervical disc).
In other instances, the cervical disc may degenerate as a result of direct trauma or gradual changes. With no blood supply and very few nerve endings, the cervical discs cannot repair themselves.
Cervical Symptoms from Degenerative Disc Disease
Cervical degenerative disc disease refers to when a cervical disc is the actual source of pain in the neck, possibly from twisting or falling on the neck but more likely from day-to-day wear and tear on the cervical spine.
Cervical symptoms related to a degenerative cervical disc may include a stiff neck and/or numbness, tingling, and weakness in the neck, arms, and shoulders as a result of a cervical nerve that has been irritated or pinched by the degeneration. Such cervical symptoms may persist for several months and fluctuate in terms of intensity.
Degenerative Cervical Disc Treatments:
- Neck Exercises
- Chiropractic Manipulation
- Cervical Spine Surgery
Patients with a degenerative cervical disc will typically begin with non-surgical treatments (NSAIDs, exercise, chiropractic, physical therapy, etc.) to seek cervical pain relief; however, if such treatment proves ineffective, a cervical spine surgery that removes the disc or fuses the spine may be necessary.
While not as common as degenerative disc disease in the lumbar spine (lower back), cervical disc disease nevertheless is a relatively common source of neck pain.