5 Potential Problems with Artificial Disc Replacement Surgery
Lumbar artificial disc replacement surgery is an alternative to spinal fusion for treating disc-related low back pain and other symptoms. While artificial disc replacement is a safe procedure with success rates similar to spinal fusion, there are several potential problems that can occur.
Some of these, such as metal allergies, complications due to improper wound care, or the downsides of seeking care outside your country, can occur with any surgical procedure. Others are specific to artificial disc replacement, including problems related to low bone density and the size of the artificial disc devices.
1. Metal Allergy or Sensitivity
Some people may have an allergy or sensitivity to the materials that make up an artificial disc. These vary among devices, but can include:
- polyethylene (plastic)
Talk to your doctor if you have a metal allergy or sensitivity, because implanting an artificial disc could cause you to have an allergic reaction. This reaction may show up as pain or swelling in the back , rash or itchiness, or other symptoms.
There have also been a few cases of people becoming hypersensitive to the artificial disc materials one or more months after surgery. These cases are rare. However, if an allergic reaction is severe enough, the implant may need to be removed.
2. Improper Wound Care
Dr. Thomas Schuler, a spine surgeon and founder of Virginia Spine Institute in Reston, Virginia, notes that proper wound care is important after any surgery, not just artificial disc replacement, adding that any wound that’s not treated properly won’t heal.
“If people don't keep the wound clean and dry, take care of it, and give it a chance to heal, then they're going to run into problems,” he says.
If a surgical wound becomes infected, a person might need to be placed on a long-term course of antibiotics to control the infection, he says. If the infection is severe enough, he adds, the artificial disc might need to be removed.
Before your artificial disc replacement surgery, talk to your doctor about proper wound care and infection protocols.
Dr. Nikhil R. Nayak, a neurosurgeon with Virginia Neurosurgeons in Arlington, Virginia, says in his practice, standard wound care generally involves washing the incision daily with soap and water. Schuler says patients should avoid submerging the wound in water, such as while bathing or swimming. Eating healthy can also help the body heal the wound, he adds.
3. Risks of Medical Tourism
Some people choose to have artificial disc replacement surgery done in another country, what’s known as medical tourism. They go this route because they believe that the procedure is less expensive in the other country, or surgeons may offer a procedure that U.S. insurance companies may not pay for, because the FDA considers it outside of the intended indications for disc replacement such as a three-level disc replacement.
However, Schuler cautions that, unless you are very familiar with another country’s healthcare system, you can’t be certain that the hospital, physicians, and nurses meet the same quality of care standards as in your own country. So you might not get what you expect.
“Once you go to other countries, anything can happen,” he says. “I’ve heard stories of great care, but I've also heard horror stories from medical tourists.”
Most health insurance companies won’t pay for procedures done through medical tourism, and they may not cover the cost of fixing a failed surgery. So if there are unexpected problems during or after surgery, you may end up paying more out of pocket for a procedure than expected.
“While the risk of surgery is low, if a patient unfortunately has a surgical complication, they will likely need to stay in the area for additional testing, management, and other aftercare,” says Nayak, “which will result in additional expenses and potential difficulties with time away from home.”
He adds that if the complication doesn’t occur until after you return home, you might find it difficult to find a local surgeon willing to take over your care. Schuler agrees, adding that revision, or salvage, cases can be more challenging for a surgeon than the original surgery.
“It’s always easiest to treat something right the first time, rather than trying to clean up messes,” he says. “Plus, you never get as good a result [with a revision] as if it were done right the first time.”
He adds that some surgeons may not have the technical skills to correct a failed artificial disc replacement. Lumbar disc replacement revisions can be especially challenging, he says, because the major blood vessels in front of the lower spine can become surrounded by scar tissue after the initial operation.
”With the lumbar spine, it’s not whether you can do the procedure, because you can,” he says. “But when you have to go back in or salvage it, you may be dealing with scar tissue that makes the operation an extreme threat to the person’s health.”
4. Low Bone Density
Artificial discs have two endplates that attach to the thick front part, or vertebral body, of the adjacent bones of the spine, or vertebrae. If a person has low bone density, the vertebral body may not be strong enough to support the artificial disc.
“Bone density is critical for all spine fusion procedures, but it's especially critical when you're talking about a motion-preserving surgery such as an arthroplasty, or a disc replacement,” says Schuler. “If you don’t have adequate support and the device subsides, then it’s not going to work.”
When the device subsides into the vertebral body, it sinks into the bone, like a thumb pressing into styrofoam. Schuler says if that happens, you lose the proper alignment of the device. One of the benefits of an artificial disc is that it preserves the motion at that level of the spine. If the device is misaligned, you no longer have that added benefit.
Bone density generally decreases with age. Many older adults have osteoporosis, but there is also a less severe type of low bone density called osteopenia. Your surgeon will check your bone density before recommending artificial disc replacement. This is less of a concern for younger patients.
“Most patients getting total disc replacement [in my clinic] are younger, so the [patient’s] bone quality has not been an issue for me,” says Nayak.
Schuler says if someone has low bone density, spinal fusion may be an option. With this surgery, you lose motion in the part of the spine that is fused. However, Schuler says a surgeon uses screws and rods to help maintain the proper alignment and balance in that area. This can reduce pain and improve function.
5. Limited Devices Sizes
Schuler says one problem with all artificial disc devices is that they are not custom-made for each person’s anatomy. ”So the manufactures had to develop a variety of sizes to cover the majority of people, but they don’t cover everybody,” he says.
A device’s size includes its core height, which corresponds to the height of the spinal disc at that level. The other component is the depth, or the footprint of the device. The footprint is represented by the endplates that attach to the vertebral bodies of the adjacent vertebrae.
While older artificial disc devices came in a limited number of sizes, that is less of a problem with more recent devices. “There is a range of sizes of total disc replacement implants,” says Nayak, “and the vast majority of patients will fit within those preset sizes.”
He says the device that he uses comes in three different heights and two different depths. Surgeons can determine which size device to use based on an MRI done before surgery. However, sometimes, once a surgeon starts operating, they may find that the device is not actually a good fit for that patient.
“Too small or too large disc space height may require the surgeon to amend the plan intra-operatively and perform a fusion instead,” says Nayak.
One of the third-generation lumbar artificial disc devices, activL, comes in four different heights, each of which fits four different endplates. This makes it easier for surgeons to choose a combination of endplate size and height that fits most patients.
Benefits of Artificial Disc Replacement
Even with these potential problems, artificial disc replacement still offers a number of benefits, such as:
- Single-level lumbar artificial disc replacement provides similar results as lumbar fusion surgery, in terms of relieving pain and other symptoms.
- Lumbar artificial disc replacement is a safe procedure with low rates of complications and need for revision surgery.
- Artificial disc replacement is a motion-preserving procedure, which allows the spine at that level to move more normally after surgery.
- Fusion surgery can put additional stress on adjacent levels of the spine, which can sometimes lead to additional symptoms later on. This is less of an issue with artificial disc replacement, because the device allows the spine to move more naturally.
- Recovery time after artificial disc replacement surgery is generally shorter than other spine surgeries, including spinal fusion. Patients who follow their surgeon’s post-surgery guidelines have a better chance of recovering quickly.
If you are considering lumbar artificial disc replacement surgery, talk to your surgeon about the benefits and risks of this procedure, and whether it is a good fit for you.