Lumbar Artificial Disc Replacement
An artificial disc replacement in the lower back replaces a diseased or damaged disc with a specialized implant that tries to preserve motion in the back. This procedure is called Lumbar Artificial Disc Replacement.
The spine is composed of individual bones called vertebrae. There are five lumbar vertebrae. They are stacked one on top of another and are separated by discs, which act as elastic cushions or shock absorbers. Discs have a soft center, the nucleus, surrounded by a tough outer ring, the annulus. Discs allow motion between the vertebrae. The interbody space is the disc space that is located between the vertebral body bones. Each vertebral segment creates a bony circle, called the spinal canal that protects the spinal cord and spinal nerves. The spinal cord, which is the nerve center of the body, connects the brain to the rest of the body. The spinal cord and nerves travel from the cervical spine down to the lowest point of your spine, the sacrum. Spinal nerves exit the spinal canal between the vertebrae at each level. Two nerves exit each level, one on the left and one on the right. These nerves exit through openings called foramen. The discs, bony structures, ligaments and strong muscles all work together to stabilize the spine.
Lumbar Artificial Disc Disease utilizes a modular device that allows the surgeon to tailor the device to a patient's distinctive anatomic requirements. While it cannot treat spinal instability, it may be performed to treat the following conditions:
- Degenerative Disc Disease
- Spinal Stenosis
- Disc Herniation
This surgery is done under general anesthesia, meaning the patient goes to sleep. During the surgery the patient lies face up on a special surgical bed. The procedure is performed through a small incision on the lower back to gain access to the spine.
Once the surgeon safely creates a window to see the spine, the damaged disc is removed with surgical tools. This part of the surgery is called a discectomy. The surfaces of the vertebral bodies are prepared to accept the implant. The bones are slightly spread apart to make more room for the disc replacement. This realigns proper curvature and enlarges the openings to relieve pressure off any pinched nerves. The artificial disc is inserted into the space between the vertebrae and carefully secured into place.
Any spine surgery has surgical risks involved. You need to discuss these with your surgeon at your pre-operative appointment. Read about General Complications from Spine Surgery.
There are differences to a disc replacement compared to a fusion however both procedures are very effective and successful treatments. Both are long term and permanent solutions to treating disc levels. The determination for either surgery can be dependent on the patient’s disease pathology.
A disc replacement is thought to reduce mechanical stress on levels of the spine above and below the replacement when compared to a fusion. Since degenerative disc disease stems mostly from genetic causes, people with spinal problems are generally more likely to develop more spinal problems in the future. There is debate as to whether a one level fusion surgery increases stress on the discs above and below causing accelerated degeneration. One argument is that fusion of one level is felt to create greater stress on the remaining “movable” joints leading to early failure. Another argument is that those discs are simply predisposed to degeneration. No study to date has proven that a fusion surgery accelerates this process. Regardless, preserving motion in the spine is an ideal outcome.