By Becky Wiese
For people who have intractable neck and arm pain or weakness and numbness in their arms, cervical disc arthroplasty (literally surgical replacement of a damaged disc with a prosthesis or implant) may offer hope for reducing pain, as well as a more natural range of movement. Dr. John Atwater, an orthopedic specialist who focuses on issues of the spine, says a cervical disc replacement provides an option other than fusion, with several benefits that make it an attractive alternative for patients who fit the criteria.
“The idea behind these disc implants is very similar to the artificial joints used for knees and hips,” says Dr. Atwater. “We remove the damaged disc and replace it with a metal and plastic joint — we re-create the normal anatomy.”
Traditionally, fusion has been the best option for relieving pain caused by damage to the cervical discs (the first seven vertebrae of the spinal column in the neck, beginning at the base of the skull). Damage can be the result of overuse, an accident, or wear due to age. “In a fusion, the damaged disc is removed and replaced with bone (a plastic implant containing bone). A metal plate secured to the surrounding vertebrae with screws helps keep the implant in place as well as helps the bone grow (fuse) between the vertebrae by preventing movement at that level,” Dr. Atwater explains.
However, securing the plate with the screws inadvertently causes stress to the surrounding discs, which often created a chain effect, which may require a fusion at the next level, and then the next. In addition, because the plate attaches to the outside of the vertebrae on the inside of the neck, it can sometimes cause difficulty in swallowing.
A cervical disc replacement fits completely in the disc space. Made of two metal plates with teeth on the top and bottom and a polyethylene insert, the implant is inserted and the teeth are pressed into the bone to secure it. Disc replacements are available in many sizes to best fit in the patient’s disc space. Choosing the size closest to the patient’s natural disc height is important, as restoring the disc height serves to un-trap nerves that cause pain. No bone is cut, and screws are not used, making it a bone-sparing device. “There’s no drilling or cutting into the bone, and nothing attaches on the front surface,” says Dr. Atwater.
Additionally, the recovery from a disc replacement is much faster. “With a fusion surgery, patients must wear a collar to keep their neck immobilized as well as limit their activity for a period of time to allow the bone to consolidate,” he explains. “After a disc replacement, we encourage patients to move much sooner. In fact, there is less need for physical therapy, so total rehab time is decreased.” Recovery is faster simply because there is no need to wait for the biological process of the bone to grow.
Several manufacturers offer single level disc replacements, per their FDA approved usage. “That’s fine, as long as only one disc is bad,” Dr. Atwater explains. “The problem is that in reality, people often have more than one problematic disc.” The next generation of disc implants has been ushered in by Mobi-C disc, which is approved to replace two adjacent damaged discs in the cervical spine. “This is ideal for a younger person with disc problems, because there is less likelihood of future problems at adjoining levels, as is the case with fusion procedures.”
The same criteria for a fusion apply for candidates of a cervical disc replacement: patients with intractable neck and/or arm pain caused by disc damage as shown in a CT, MRI, or X-ray and who have tried non-surgical forms of treatment such as physical therapy, medication, or injections with no relief, or possibly worsening in spite of treatment. “Patients who are younger and more active and rely on free neck movement make good candidates,” says Dr. Atwater.
The overall benefit of cervical disc replacement includes alleviating pain and preserving movement in the cervical spine — meaning patients can bend side-to-side (lateral movement), forward-to-back (flexion and extension), and turn left-to-right (rotation).
More movement and less pain — exactly what the doctor ordered.
Dr. Atwater focuses on spine conditions and can provide a full range of treatment options, including all types of spine surgery if necessary. He has been named one of the 50 best spine surgeons by the Becker Orthopedic & Spine Review. For more information, you may contact Dr. Atwater at McLean County Orthopedics, 309-662-2628. Their office is located at 2502 East Empire in Bloomington.
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