What might go wrong?
All types of spine surgery, including artificial disc replacement, have certain risks and benefits. Complications from any kind of surgery can also occur from anesthesia, infection, and development of blood clots (thrombophlebitis). Medical complications arising from spinal surgery are rare but could include stroke, heart attack, spinal cord or spinal nerve injury, pneumonia, or possibly death.
Your spine surgeon will discuss the most common complications with you. This document will help you prepare any questions you may have. It doesn’t provide a complete list of all the possible complications. Complications from the artificial disc replacement procedure are rare and are lower than for spinal fusion. Results continue to improve with advances in technology and better surgical techniques. The more common problems may include but are not limited to:
- problems with anesthesia
- thrombophlebitis (blood clots)
- nerve damage or paralysis
- spontaneous ankylosis (fusion)
- problems with the implant
- retrograde ejaculation (men only)
- ongoing pain
Problems can arise when the anesthesia given during surgery causes a reaction with other drugs you may be taking. In rare cases, a patient may have problems with the anesthesia itself. In addition, anesthesia can affect lung function because the lungs don't expand as well while a person is under anesthesia. Be sure to discuss the risks and your concerns with your anesthesiologist.
Thrombophlebitis (Blood Clots)
Thrombophlebitis, sometimes called deep venous thrombosis (DVT), can happen after any operation. It occurs when blood in the large veins of the leg forms blood clots. This may cause the leg to swell and become warm to the touch and painful. If the blood clots in the veins break apart, they can travel to the lung, where they lodge in the capillaries and cut off the blood supply to a portion of the lung. This is called a pulmonary embolism. (Pulmonary means lung, and embolism refers to a fragment of something traveling through the vascular system.) Most surgeons take preventing DVT very seriously. There are many ways to reduce the risk of DVT, but probably the most effective is getting you moving as soon as possible after surgery. Two other commonly used preventative measures include
- pressure stockings to keep the blood in the legs moving
- medications that thin the blood and prevent blood clots from forming
Infection following spine surgery is rare but can be a very serious complication. Some infections may show up early, even before you leave the hospital. Infections on the skin's surface usually go away with antibiotics. Deeper infections that spread into the bones and soft tissues of the spine are harder to treat. They may require additional surgery to treat the infected portion of the spine.
Nerve Damage or Paralysis
Any surgery that is done near the spinal canal can potentially cause injury to the spinal cord or spinal nerves. Injury can occur from bumping, stretching, or cutting the nerve tissue with a surgical instrument. Nerve involvement can cause nerve pain, muscle weakness, and a loss of sensation to the areas supplied by the nerve.
These symptoms are usually temporary and will gradually go away in one to three months’ time. Swelling around the nerve or the formation of scar tissue can also result in pressure or traction on the nerve. Scar tissue called fibrosis does not always resolve resulting in chronic pain and long-term weakness and sensory changes.
Scientists aren’t sure why but sometimes the spine fuses itself, a process called spontaneous ankylosis. Loss of spinal motion is the main side effect of this problem. Bone may also form in the soft tissues around the vertebrae. For example, cartilage turns to bone or bone-like tissue. This process is called ossification. Ossification may or may not affect the implant or your final results in terms of motion or function.
Problems with the Implant
The prosthesis itself can sometimes be a source of complications. Although rare, the prosthesis can shift out of its normal position and even dislocate. If the implant migrates out of position, it can cause injury to the nearby tissues. A second surgery may be needed to align or replace the implant.
And similar to other types of joint replacements, the artificial disc may fail over time if the parts wear out. Your ADR is estimated to last 15 to 20 years. If the disc moves out of position or wears out, it can be removed. When surgery is done to take out the original prosthesis, a fusion surgery will most likely be recommended.
Subsidence is another possible problem. The implant actually sinks down into the vertebral body above or below it. This results in a loss of the normal disc height. Neurologic compression with neurologic symptoms can occur.
Over time, wear and tear just from the physical process of motion across a bearing surface can cause tiny bits of debris to flake off the implant. The body may react to these particles with an inflammatory response that can cause pain, implant loosening, and implant failure. So far, significant inflammatory reactions have not been reported for spinal ADRs.
Lumbar disc replacement surgery carries risks associated with operating from the front of the spine. In men, the anterior approach can also sometimes result in a complication called retrograde ejaculation.
Tiny nerves in front of the lower spine may be damaged during the anterior approach. If so, semen enters the bladder instead of going out through the urethra during ejaculation. Male patients planning a family might wish to consider donating sperm before surgery. Studies have not reported cases of sexual dysfunction but it is a potential risk.
Not all patients get complete pain relief with this procedure. As with any surgery, patients should expect some pain afterward. If the pain continues or becomes unbearable, talk to your surgeon about treatments that can help control your pain.