I'm looking into the possibility of having a disc replacement in my neck (around C6). I saw in a brochure about the procedure that the implant can shift causing problems later. If that happens, could my neck get stuck in a certain position or what?
Artificial disc replacement for the cervical spine (neck) have been used for the last 10 years, so the first batch of long-term studies are just coming out. Researchers are looking at many things in these studies. For example, what are the potential problems? How often does the patient need another surgery? Does everyone keep good neck motion years later?
One of the possible adverse events that can occur with any implant is migration or movement of the device. Sometimes it's just a minor shift or sinking into the bone. The patient may not even be aware of it until an X-ray is taken showing the changes. But a significant shift of the implant can put pressure on the spinal cord or nerve roots, resulting in neck and/or arm pain and neurologic symptoms. That's when the surgeon may have to go in and remove the device and fuse the spine.
The few studies that are out show pretty good results overall for cervical spine artificial disc replacements. Although many patients have one problem or another, most of these are minor and don't require a second surgery to correct. Significant symptoms (especially pain or paralysis) or loss of neck alignment would be addressed immediately.
You would not be in any danger of getting your neck stuck in some unusual position. Loss of motion may increase your neck stiffness or make it more difficult to flex, turn, or side bend your head. These are rare and unusual events that you aren't likely to experience.