What is Cervical Disc Injuries?
The spinal cord is like a long cable of nerve tissue that runs from the medulla oblongata, part of your brain, down to your lower back. It’s protected by your spine, which is made up of a series of bones called vertebrae. There are different types of vertebrae, seven in your neck (cervical), twelve in your chest area (thoracic), five in your lower back (lumbar), five in your pelvic area (sacral), and three to five at the very bottom of your spine (coccygeal).
The seven neck vertebrae are labeled C1 to C7, starting from the base of your skull. C1, C2, and C7 have unique structures compared to C3 through C6. The structure of C3 to C6 includes a central body with “pedicles” (small stalk-like parts) in the front, and “lamina” (flat sections) in the back, forming a ring around the spinal cord. Movement mainly occurs at the top and bottom joints with the vertebral artery, vein, and a network of nerves running through a hole in the transverse process, a bony projection off the back of each vertebra.
The C1 vertebra (also known as the “atlas”) connects your skull to your spine, mostly through ligament attachments. It doesn’t have a body of its own, but is fused with the C2 vertebra (called the “axis”), which acts like a pivot for the atlas to rotate. The C2 vertebra has a unique, strong upright structure called the odontoid process (or “dens”) projecting from its upper surface. The body of the C2 vertebra is deeper in the front than the back and extends downwards at the front, so it overlaps the top and front part of the C3 vertebra. The C7 vertebra has a long and noticeable bony projection, which you can feel through your skin.
Each neck vertebra is separated by what’s known as a cervical disc. These discs are made up of a gooey inner part (nucleus pulposus) and a tough outer ring (annulus fibrosus). This design allows for flexibility in your neck but it can also make it more vulnerable to injury compared to the sturdier thoracic spine.
What Causes Cervical Disc Injuries?
Degenerative disc disease and acute disc herniation, often seen in the neck area, are common types of spinal disorders. Degenerative disc disease occurs when the disc, which is a soft cushion between the bones in your spine, loses its moisture content. This results in reduced flexibility and can increase the likelihood of developing facer joint disease, a type of arthritis in the spine.
These conditions can also be brought on by traumatic injuries. For example, playing contact sports, or getting into a car accident, can increase your risk of disc herniation, when a disc in the spine ruptures and leaks, irritating nearby nerves.
Risk Factors and Frequency for Cervical Disc Injuries
Neck pain, often caused by a condition called cervical disc disease, impacts up to 15% of people in the United States. This translates to approximately 84 out of every 100,000 individuals suffering from neck pain. Cervical disc injuries, which often result from disc herniation, are most common in individuals in their thirties to forties. Conversely, degenerative disc disease, another cause of neck pain, typically affects people who are older than 50.
Signs and Symptoms of Cervical Disc Injuries
People with a cervical disc injury mainly complain about neck pain. Sometimes, this pain can also spread to the arm and fingers. When health professionals assess these patients, they should find out the details about the pain – how severe it is, when it began, how long it lasts, and what it feels like. They should also ask about things that make the pain better or worse, and any other symptoms that come with the pain. Other symptoms could include muscle spasms, reduced movement, and a feeling of numbness or shooting pain.
A careful physical examination should also be conducted. This would involve a doctor checking the feeling and movement in the relevant areas. They should also look at how far the patient can move their neck – how much they can bend and extend their neck, turn it to the right and left, and bend it side to side. The extent of these movements can be affected by the severity of the pain, spasms, or degeneration.
Testing for Cervical Disc Injuries
If you have a possible issue with your cervical spine (the neck area of your backbone), your doctor may start with an inexpensive method called a plain X-ray. This method can help the doctor look for any injuries to the bone structure in your neck. X-rays can show things like disc degeneration, which appears as a reduction in the space between your spinal bones and bony spurs known as osteophytes. The use of plain X-rays can also show cervical spine stenosis, or a narrowing of the space where your spinal cord passes.
One thing that doctors might measure on your X-ray images is the Torg ratio. This is the ratio of the space inside your spinal canal to that of the body of your vertebrae (the main part of your spinal bones). Normally, this ratio is 1.0. If it falls to 0.8 or below, that suggests you may have cervical spinal stenosis.
Magnetic resonance imaging (MRI) is another method for checking the condition of your cervical spine. It’s the best option if your doctor needs a clear view of any pressure on your spinal cord or disc herniation (when the cushion-like discs between your spinal bones bulge or break open). Your doctor would specifically use T2 weighted views, this provides best imaging for such conditions. The MRI can show decreased disc height, lower signal intensity, and spondylotic osteophytes, which are bony growths that occur with wear-and-tear changes in the spine, also known as spondylosis.
If those methods don’t provide enough information, your doctor might recommend a discography. This procedure involves injecting a dye into a spinal disc and then taking an X-ray or conducting a CT scan. The images can help to identify damaged discs. Your doctor may also recommend electrophysiological studies. These are tests that can help to pinpoint which nerve roots may be affected by a damaged cervical disc.
Treatment Options for Cervical Disc Injuries
When dealing with acute conditions, treatment often starts with relieving pain, starting physical therapy, and considering surgery if needed.
Non-Surgical Treatment
The first step in any treatment plan starts with relieving pain to lower inflammation. Once inflammation is under control, physical therapy can begin. The therapy generally includes guided exercises to help reduce pain, increase the ability of the muscles to move, strengthen muscles, and improve how the spine moves. Over-the-counter anti-inflammatory medications or epidural injections (painkillers delivered close to the source of the pain in your spine) are often used to initially control pain. In severe cases, medical procedures like medial branch blocks or rhizotomies, which specifically target nerves causing the pain, may be needed.
Surgical Options
If the pain doesn’t improve or gets worse with non-surgical treatments, surgery might be the next option. This is especially true when the cause of the pain is a disc herniation (popping out of the cushion-like discs between bones in your spine) resulting in central cord syndrome (a spinal cord injury causing loss of movement and sensation). There are various surgical techniques depending on the specific issue. For example, if the herniated disc is located in front or at the center, removing it and fusing the adjacent spinal bones (anterior discectomy with fusion) is often recommended. However, if surgery has been done at the same spot before, or if the disc cannot be easily accessed from the front, a procedure to create space without removing the spinal bone (laminoplasty) or removing part of the spinal bone (laminectomy) may be considered.
Surgery is usually considered for patients who have been managing their disc herniation or degenerative disc diseases (wear and tear on spinal discs) with non-surgical treatments for 6 weeks to 3 months without significant improvement. A worsening neurological condition is also an indication for surgery.
There are a few types of surgeries that can be performed depending on the patient’s condition. These include total disc replacement, anterior cervical discectomy and fusion (ACDF), laminectomy, or laminoplasty. The choice of surgical procedure will depend on your specific spinal problems and symptoms.
Brief Overview of Surgical Techniques
Total Disc Replacement (TDR) & Anterior Cervical Discectomy and Fusion (ACDF)
The surgeon will make a small cut in the front of the neck to get access to the disc. Special tools are used to remove the diseased disc. If a disc replacement is being done, a synthetic substitute is inserted. If an ACDF is being done, the space is filled with an implant. The procedure may be followed by attaching a support plate if needed. Following surgery, some patients may experience difficulty in swallowing, voice changes, and a sore throat. However, most patients find relief from their original symptoms and can return to full activity after about six months.
Laminectomy
In a laminectomy, the surgeon removes part of the spinal bone to create more room for the spinal cord. This is mainly used for conditions like spinal stenosis (narrowing of the spaces within the spine, which can put pressure on the nerves) or degeneration in multiple levels of the disc causing pressure on the spinal cord from the front. The procedure may carry risks including spinal deformity, chronic muscle pain, and headaches.
Laminoplasty
To prevent spinal deformities that may happen after laminectomy, laminoplasty was developed. This procedure reshapes the spinal bones to make more room for the spinal cord, without having to remove them. It is mainly used for spinal cord compression caused by spinal bones pressing on the spinal cord across multiple levels. Following surgery, about 11% of patients might experience nerve root injury due to tension on the nerve root as the spinal cord shifts position.
What else can Cervical Disc Injuries be?
Here are some conditions or issues that could affect the cervical spine and require rehabilitation or treatment:
- Cervical discogenic pain syndrome
- Cervical facet syndrome
- Cervical radiculopathy
- Cervical spine sprain
- Rehabilitation for osteoarthritis
- Rehabilitation for Paget disease
- Rheumatoid arthritis
- Rotator cuff disease
- Thoracic outlet syndrome
- Traumatic brachial plexopathy
