We all know that every surgery is associated with a certain amount of risk, but what does that actually mean? What patients really want to know: is cervical disc replacement safe? In this article, we discuss the risks of cervical disc replacement by reviewing the numbers and the probabilities so you can assess and determine if cervical disc replacement is safe for you.
It is perfectly reasonable for patients to consider the safety of cervical disc replacement. After all, a surgeon makes an incision in your neck and works in an area with several important structures including major blood vessels, the esophagus, and the spinal cord. Spine surgery attracts the best and the brightest surgeons, and for good reason—there is a lot at stake.
Surgeons and health scientists assess the safety and risk of the procedures they perform in a rather simple way. They look at a large number of people who have had a certain procedure and track the type and number of complications that have occurred.
Intraoperative risk of cervical artificial disc replacement
When scientists examined surgical outcomes across 21 surgical centers in North America in 258 patients who had cervical disc replacement surgery, they found reassuring results. There were no deaths that occurred during surgery. So, the intraoperative death rate was 0%. The most common serious complication that occurred during surgery was a dural tear, which is a break in the covering of the spinal cord. Dural tears occurred in 0.77%, or fewer than 8 cases in 1,000. Other serious complications were related to temporary or permanent nerve injury, and each occurred less frequently than 2 times out of 258. Besides death, the most feared complication is paralysis, had an incidence rate of 0.02%, or 1 in 10,000 cases. Most would say these complication rates are very low, but you should make your own assessment.
Postoperative risk of cervical artificial disc replacement
Several complications may emerge after cervical artificial disc replacement surgery. Fortunately, the serious complications are relatively rare and the common ones are usually temporary.
Dysphagia
Dysphagia, or trouble with swallowing, is very common in life after cervical disc replacement. It may occur in as many as 7 in 10 patients immediately after surgery. In fact, it happens so often that some surgeons consider it an unavoidable part of the surgery rather than a true complication. Dysphagia is almost always temporary and resolves within hours to 1-2 days. Sometimes it resolves in 2-3 weeks. Careful surgical technique may reduce the incidence and severity of dysphagia.
Infection and blood loss
Excessive blood loss and infection are unlikely to occur during cervical artificial disc replacement surgery. In a randomized control trial of 541 patients undergoing cervical artificial disc replacement surgery or cervical spinal fusion, blood loss was minor about the same in both groups (about 2 ounces) and there were no infections. Temporary blood vessel injury may occur in about 1 out of 200 patients
Heterotopic ossification
Heterotopic ossification means that bony material grows in someplace other than in a known bone. In other words, bone may start to grow on and around the artificial disc after cervical artificial disc replacement surgery. It is very difficult to determine how often heterotopic ossification actually happens. It could occur in many cases, but not cause any symptoms or disability. Severe heterotopic ossification can be a problem, however, because it can interfere with range of motion in the neck (becoming closer to fusion surgery than artificial disc replacement surgery). The rate of severe heterotopic ossification may occur in as many out of 1 in 10 patients within the first 2 years after cervical artificial disc replacement surgery. However, excellent surgical technique and certain intraoperative actions can reduce the rate of heterotopic ossification
Disc migration
Artificial discs only work well if they are placed well and stay in place. Unfortunately, that is not always the case. An artificial disc can migrate or move out of its intended position. This can cause pain, decreased range of spinal motion, and possibly require a second surgery. The rate of disc migration happening appears to be about 2 to 3 times in every 100 patients. While that sounds like a lot, we know that a large number of these cases can be avoided in two ways: patient selection and excellent surgical technique. Disc subsidence and migration occurs much more often in people who have “weak bones” that is, osteopenia, osteoporosis, or some disease of bone metabolism. Consequently, people with these conditions are poor candidates for artificial disc replacement surgery. In those without “weak bones,” surgeons can reduce the risk of disc subsidence and migration by avoiding end plate violations during disc preparation and choosing an implant that is too small.
As with any medical or surgical procedure, the decision comes down to benefits versus risks. How likely is it that you are going to experience relief from neck pain? How likely are you going to regain neck mobility? How likely is it that you are going to experience a minor or serious complication? Ultimately, is the benefit worth the risk?
Your surgeon will be an essential partner in helping you determine if artificial disc replacement is right for you. The first decision is whether you need spine surgery at all. Most people who have chronic neck pain that does not resolve after six months of medical care and physical therapy are candidates for corrective spine surgery.
Once you have determined that spine surgery is right for you, you must choose between two procedures: cervical artificial disc replacement surgery and cervical fusion surgery (ACDF). In properly selected patients performed by skilled spine surgeons, the complication rates after cervical artificial disc replacement surgery are virtually identical to those after cervical fusion surgery (ACDF). The major difference is in how flexible the neck is after surgery. After fusion surgery—a procedure in which the spinal bones are fused together—the neck loses a great deal of mobility. After cervical artificial disc replacement surgery, neck motion is preserved or restored. This means that if people are candidates for cervical artificial disc replacement surgery, they will often choose that procedure because they get to retain neck mobility with the same degree of neck pain relief and without additional risk.
But how do you know if you are a candidate for cervical artificial disc replacement surgery? Your surgeon will help you determine if you are a candidate for this procedure by assessing your unique anatomy, your particular cause of neck pain, and whether you have healthy spinal bones.
Lastly, ask the spine surgeon about how many procedures they have performed, both ACDF and cervical artificial disc replacement. Also ask the surgeon about their own complication rates and determine if that rate of risk is acceptable to you. Surgeons with low complication rates are not only technically skilled surgeons, but they are also good at selecting the right patients for the right procedure. If you have found a board-certified spine surgeon who has performed numerous spine surgeries of both kinds with low complication rates, you are almost certainly in good hands.