Introduction
Degenerative disc disease is a prevalent cause of neck pain, characterized by the deterioration or breakdown of the spinal discs. For individuals suffering from degenerative cervical disc disease, artificial cervical disc replacement can serve as an alternative to anterior cervical discectomy and fusion (ACDF). Unlike spinal fusion, this procedure promotes more natural spinal motion, restores the normal height of the disc, and allows for near-normal stress absorption within the spine.
Anatomy
The spine consists of a series of bones known as vertebrae, organized into distinct regions based on their curvature and function. The cervical spine is comprised of seven small vertebrae located in the neck. Each vertebra features a back portion called the lamina, which forms a roof-like structure over the vertebra's rear opening. This central opening creates the spinal canal, through which the spinal cord, nerves, and arteries travel, serving as a conduit for messages between the body and brain.
Intervertebral discs are situated between the vertebrae and are composed of robust connective tissue. Each disc has a tough outer layer known as the annulus fibrosus and a gel-like center called the nucleus pulposus, with healthy discs containing approximately 80% water. The discs, along with two small spinal facet joints, connect each vertebra, allowing for movement and providing stability. Additionally, these discs act as shock-absorbing cushions, protecting the vertebrae.
Causes
Degenerative disc disease can affect any area of the spine. As individuals age, their discs may lose fluid, collapse, or rupture, resulting in reduced space between the vertebrae. This deterioration can alter the vertebrae's structure and lead to conditions that place pressure on the spinal cord and nerves. While most symptoms can be managed with non-surgical treatments, surgery may be necessary if the spine becomes unstable or if pain is unmanageable through other means.
Symptoms
Intervertebral discs typically function as cushions between the vertebrae. When a disc degenerates, pain can arise from various sources. Abnormal bone growths, known as bone spurs, may form in the joints and encroach upon the spinal canal. A damaged disc can compress nerves, leading to pain, burning sensations, tingling, pressure, weakness, and numbness, which may radiate into the arms.
Diagnosis
Diagnosis of degenerative disc disease involves a physical examination and imaging studies. Your doctor will inquire about your symptoms and medical history, assess muscle strength, joint motion, and stability, and conduct a neurological examination of your arms and legs to evaluate nerve function.
X-rays can be used to assess the condition of the vertebrae, and in some cases, a myelogram—where dye is injected into the spinal column—can enhance X-ray images, revealing potential pressure on the spinal cord or nerves from herniated discs, bone spurs, or tumors.
Computed tomography (CT) scans may be ordered to examine the shape and size of the spinal canal and surrounding structures, sometimes accompanied by a CT myelogram involving dye injection. A discogram allows for a view of the internal structure of a disc by injecting dye directly into it, which can help identify pain sources. Magnetic resonance imaging (MRI) provides the most detailed visualization of the discs, ligaments, spinal cord, nerve roots, and tumors.
Treatment
Most individuals with degenerative disc disease undergo non-surgical treatments aimed at alleviating pain. These treatments focus on pain relief and restoring function but do not address structural deformities. If non-surgical methods yield minimal or no improvement, surgery may be recommended. Traditionally, spinal fusion surgery is performed to remove the degenerative disc and fuse two or more vertebrae, but this procedure can limit movement. An alternative is artificial cervical disc replacement.
Surgery
The primary objective of artificial cervical disc replacement is to relieve pain while preserving spinal motion, reducing further degeneration, and enabling a quicker return to daily activities. This surgery is typically performed at specific levels of the spine (C3-C7), and your surgeon will discuss the most suitable artificial disc options for your case.
The procedure requires hospitalization and begins with a small incision at the front of the neck. The surgeon removes the damaged disc and surrounding tissue, creating a space between the vertebrae that accommodates the artificial disc. The vertebral space is then restored to its normal height to alleviate nerve pressure, and the artificial disc is positioned in the prepared space.
Recovery
Post-surgery, patients usually stay in the hospital for one to two days. Most individuals can return home with minimal restrictions on movement. Recovery from artificial disc replacement generally occurs more swiftly than from fusion surgery, as the artificial disc allows for natural spinal motions, including flexion, extension, rotation, and lateral bending.
