Adjacent Segment Disease
The human spine is built for movement. Spinal fusion surgeries use bone grafts and/or hardware to permanently “lock” together two or more vertebrae for the purpose of making a section of the spine thought to be producing pain symptoms immovable. After a fusion surgery, you’ll likely lose the ability to move your spine at the place where the procedure was done. This means you will no longer be able to bend forward, arch back, twist or tilt your spine at the specific level or levels addressed in surgery.
This “locking” of the spine’s segment invariably forces adjacent parts of the spine to compensate and try to keep the spine flexible. Unfortunately, this stresses and overloads those upper and lower vertebrae, forcing the intervertebral discs to break down and causing nerve compression and pain after back fusion leading to a condition known as Adjacent Segment Disease (ASD). ASD is most likely to occur in the motion segments of the spine used most often, such as L4/L5 and L5/S1 near the highly mobile lower lumbar region and C5/C6 and C6/C7 near the highly mobile upper cervical region.
Adjacent Segment Disease Conditions
This overloading of the adjacent segments of the spine brought on by spinal fusions can result in a number of conditions in the adjacent segments, including:
• Degenerative arthritis in the facet joints
• Stenosis (narrowing of the spaces for the nerves)
These conditions all have the capacity to compress nerves in the spine, causing pain, and conditions including:
• Radiculopathy: pain that radiates into the arms or legs
• Myelopathy: pain that travels along the spinal cord
Approximately 25% of patients who have undergone fusions develop Adjacent Segment Disease about 5 years post-surgery. For those undergoing three- or-four level fusions 29% develop ASD at 5 years and 40% at 10 years.
Diagnosing Adjacent Segment Disease
To diagnose adjacent segment disease, your doctor will likely evaluate any radiculopathy and/or myelopathy. If your doctor can trace those types of pain back to the motion segments above and/or below your surgery site, you may have adjacent segment disease.
Treating Adjacent Segment Disease
Because the conditions resulting from Adjacent Segment Disease are new conditions brought on by nerve compression, conservative treatment may be initially advised, such as:
• Physical therapy
• Cortico steroids
However should these conservative treatments fail to relieve the pain, surgery may be necessary. Traditionally extended fusions or the implantation of interspinous devices have been recommended. The Bonati Spine Institute strongly recommends against extended fusions and implants, since these procedures result in higher rates of ASD in the adjacent segments.
Additionally artificial disc replacements are sometimes recommended for ASD. However, researchers writing in the European Spine Journal, looked at nearly 15 years of data from several studies and found a complication rate for implanted artificial discs of over 50 percent. Potential complications associated with artificial disc surgery may include an allergic reaction to the implant material, implanted discs bending, breaking, loosening, or moving, and nerve or spinal cord injury, possibly causing impairment or paralysis.
The Bonati Spine Procedures have been shown to be highly effective in decompressing the nerves without fusions to treat spinal conditions and very successful in avoiding adjacent segment disease. These procedures produce far fewer complications and preserve motion of the spine, therefore, the potentially deleterious effects of spine and ASD is avoided. The Bonati Spine Procedures can also benefit patients who have already undergone spinal fusions and suffer from ADS symptoms. For more information on how these procedures may help you avoid ASD or be the answer to your ASD simply call (855) 267-0482.