Intervertebral Disc Replacement | Specialists and Information

The spine consists of 24 vertebrae, each of which comprises a compact vertebral body and a hole formed by the vertebral arches.

As the vertebral bodies are arranged in a row, the openings form the spinal canal (nerve canal). The spinal cord, a part of the nervous system, runs through this canal. The spinal nerves exit the spinal canal between the vertebral arches.

Acting as a kind of shock absorber, the intervertebral discs connect two vertebral bodies to each other. This is why the intervertebral disc is also called the vertebral disc. It consists of an outer fibrous ring and a centrally located gelatinous nucleus. The gelatinous nucleus, in particular, absorbs shocks to the spine.

Over the course of a person’s life and due to ongoing stress, the water content in the gelatinous nucleus decreases. The intervertebral discs become thinner, and pathological changes (degeneration) can occur in the bone of the vertebral bodies.

Small tears in the fibrous ring can allow the gelatinous nucleus to protrude through the ring. This results in a herniated disc. The herniated disc can then press on the spinal nerves or the spinal cord, causing severe pain and neurological deficits.

A herniated disc in the lumbar spine manifests as severe lower back pain, muscle tension, sensory disturbances, or paralysis @ Henrie /AdobeStock

A disc prosthesis consists of two metal plates attached to the vertebral bodies and a movable plastic core. Doctors typically insert it from the front, that is, through the neck or the abdomen.

The prosthesis replaces the intervertebral disc, relieves pain, and reduces pressure on the spinal cord and nerves @ Foxstudio /AdobeStock

The main reasons for implanting intervertebral disc prostheses are pain and/or neurological deficits.

These are the result of age-related, stress-related, or disease-related changes in the intervertebral disc or the vertebral bodies. 

In the case of a herniated disc, doctors relieve pressure on the nerves by removing the herniated disc material. By inserting an intervertebral disc prosthesis, they restore the correct spacing between the vertebral bodies. The mobility of the vertebrae is generally preserved.

In spondylosis, persistent improper loading and obesity lead to degenerative changes in the vertebral bodies.

New bony structures form, which exert pressure on the spinal nerves or lead to stiffening of the spine.

Before implanting the intervertebral disc prosthesis, doctors remove the new bony growths.

If the intervertebral discs and adjacent bone structures are degeneratively altered, the condition is known as osteochondrosis.

Specialists in intervertebral disc replacement also treat mild forms of myelopathy (spinal cord damage) caused by a narrowing of the spinal canal. Medical professionals refer to this as spinal stenosis or spinal canal stenosis.

Spinal canal narrowing (stenosis) results in a constriction within the spinal canal @ Axel Kock /AdobeStock

Nonspecific lower back pain, provided it originates from the intervertebral disc, may be a reason for implanting an artificial disc.

Through a patient interview (medical history) as well as a physical and clinical examination, doctors can usually narrow down the causes of the symptoms.

Using imaging techniques, experts in intervertebral disc replacement can assess:

• Spine
• Vertebrae
• Intervertebral discs
• Spinal canal
• Spinal cord

X-rays of the spine show changes in the vertebral bodies (such as spondylosis). The doctor can assess the intervertebral spaces. They can also be used to produce dynamic X-rays to evaluate stability and mobility.

A damaged intervertebral disc may be visible on an X-ray taken with contrast dye @ endostock /AdobeStock

Using magnetic resonance imaging (MRI) or computed tomography (CT), the doctor can also evaluate the intervertebral discs and the spinal canal. This allows for the detection of possible herniated discs.

Myelography is now rarely used. In this procedure, doctors inject contrast dye into the spinal canal to better visualize the spinal cord and spinal nerves.

Before a potential intervertebral disc replacement surgery, doctors may inject a contrast agent directly into the intervertebral disc space (discography). This allows them to observe how the contrast agent spreads on an X-ray. Depending on how the contrast agent is distributed, they can draw conclusions about the nature of the disc damage.

The range of services offered by a specialist in intervertebral disc endoprosthetics includes, among others, the following methods:

• Removal of a herniated disc in the cervical and lumbar spine and implantation of an artificial disc
• Treatment of osteochondrosis through the implantation of an intervertebral disc prosthesis
• Removal of bone spurs in spondylosis and implantation of an artificial disc
• Decompression surgery for spinal canal stenosis by removing the bone and ligament structures causing the narrowing

Experts in intervertebral disc replacement are typically board-certified specialists in orthopedics and trauma surgery or board-certified specialists in neurosurgery. They have specialized experience in the implantation of intervertebral disc prostheses.

When deciding whether or not to proceed with surgery, they weigh the benefits against the risks. They consider possible alternatives to a disc prosthesis. Through certifications, they ensure a high standard of surgical care.