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Possible Complications


With any surgery, there is the risk of complications. When surgery is done near your spine and spinal cord, these complications can be very serious if they occur. The chance that any of these complications will occur during your surgery or during your recovery is usually very small. You should discuss these complications with your doctor before surgery if you have any questions that are not answered here. This is not intended to be a complete list of the possible complications, but these are the most common.

General Complications

Anesthesia Complications

Most spinal operations require general anesthesia. A very small number of patients may have problems from it. These problems can arise from reactions to the drugs used, other medical conditions you may have, or problems with the anesthesia. Anesthesia affects how your lungs work and can pose problems with lung infections. Nausea and vomiting can occur and are usually treated with medications. The tube inserted into your throat may cause soreness after surgery. In rare cases the tube can harm your vocal cords. Be sure to talk to your doctor and anesthesiologist about possible complications.


Surgery on your spine involves the risk of unexpected bleeding. Spine surgeries performed through your abdominal cavity require your doctor to move your abdominal aorta and the large blood vessels going to your legs out of the way. Doctors take extra care while performing surgery to avoid harming nearby blood vessels.

Blood Clots

Deep venous thrombosis (DVT) (or thrombophlebitis) is the medical name to describe blood clots formed in the veins of your legs. This is a common problem following many types of surgical procedures. These blood clots form in the large veins of your calf. They may continue to grow and extend up into the veins of your thigh, and in some cases into the veins of your pelvis.

It is true that some people develop DVT even though they have not undergone any recent surgery. But the risk is much higher following surgery, especially surgery involving your pelvis or the lower extremities. There are logical reasons why the risk is increased. Your body is trying to stop the bleeding associated with surgery, so your body's clotting mechanism becomes very active during this period. Also, injury to blood vessels around the surgical site from normal tugging and pulling during surgery can set off the clotting process. Blood that does not move well sits in your veins and becomes stagnant. If it sits too long in one spot it may begin to clot.

The prevention of DVT is a serious matter. Blood clots in the deep veins of your legs stop the normal flow of venous blood from your legs back to your heart. This causes swelling and pain in the affected leg. If the blood clot inside the vein does not dissolve, the swelling may become chronic and can cause permanent discomfort. While the discomfort is unpleasant, the blot clot actually poses much more serious danger. If a portion of the forming blood clot breaks free inside the veins of your leg, it may travel through the veins to your lung. There it can lodge itself in the tiny vessels of your lung, cutting off the blood supply to the blocked portion of your lung. This blocked portion cannot survive and may collapse. This is called a pulmonary embolism. If a pulmonary embolism is large enough, and the portion of the lung that collapses is large enough, it can cause death.

Reducing your risk of developing DVT is a high priority following any type of surgery. Preventative measures fall into two categories: mechanical and medical. Mechanical prevention involves getting your blood moving better, and medical prevention involves using drugs to slow the clotting process.


Blood that is moving is less likely to clot. Getting you moving so that your blood is circulating is perhaps the most effective treatment against developing DVT. Once you begin walking, your leg muscles will contract and keep the blood in the veins of your legs moving. But you can still do things while you are in bed to increase the circulation of blood from your legs back to your heart. Simply pumping your feet up and down (like pushing on the gas pedal) contracts the muscles of your calf, squeezes the veins in your calf, and pushes the blood back to your heart. You should do these exercises as often as you can.

Pulsatile stockings are very effective. They are special stockings that wrap around each calf and thigh. A pump inflates them every few minutes, squeezing the veins in your legs and pushing blood back to your heart. Support hose, sometimes called TED hose, is still commonly used following surgery. The hose works by squeezing the veins of your leg shut. This reduces the amount of stagnant blood that is pooling in the veins of your leg and lowers the risk of blood clotting.


Medications that slow down your body's clotting mechanism can reduce your risk of DVT. They are widely used following surgery of the hip and knee. Aspirin can be used in very low risk situations. Heparin shots may be given twice a day in moderately risky situations. When there is a high risk for developing DVT, several potent drugs are available that can slow the clotting mechanism very effectively. Heparin can be given by intravenous injection, a drug called Lovenox can be given in shots administered twice a day, and Coumadin can be given by mouth. Coumadin is the drug of choice when the clotting mechanism must be slowed for more than a few days because it can be taken orally.

In most cases of spinal surgery, both mechanical and medical measures are used simultaneously. It has become normal practice to use pulsatile stockings and place patients on some type of medication to slow the blood clotting mechanism. You are encouraged to get out of bed as soon as possible and begin exercises immediately after surgery.

Dural Tear

Dura mater is the watertight sac of tissue that covers your spinal cord and spinal nerves. A tear in this covering can occur during surgery. It is not uncommon to have a dural tear during any type of spine surgery. If noticed during the surgery, the tear is simply repaired and usually heals uneventfully. If it is not noticed during surgery, the dural tear may not heal and may continue to leak spinal fluid, which can cause problems later. The leaking spinal fluid may cause a spinal headache. It can also increase the risk of infection of your spinal fluid (spinal meningitis). If a dural leak does not seal itself off fairly quickly on its own, a second operation may be necessary to repair the tear in the dura.

Lung Problems

It is important that your lungs are working at their best following surgery to ensure that you get plenty of oxygen to the tissues of your body that are trying to heal. Lungs that are not exercised properly after surgery can lead to poor blood oxygen levels and can even develop pneumonia.

There are several reasons why your lungs may not work normally after surgery. If you were put to sleep with a general anesthetic, the medications used may temporarily cause your lungs to not function as well as normal. This is one reason that a spinal-type anesthetic is recommended whenever possible. Also, lying in bed prevents completely normal function of your lungs, and the medications you take for pain may cause you to not breathe as deeply as you normally would.

After surgery you will need to do several things to keep your lungs working at their best. Your nurse will encourage you to take frequent deep breaths and cough often. Getting out of bed, even upright in a chair, allows your lungs to work much better. You will be allowed to get up and into a chair as soon as possible. Respiratory therapists have tools to help you maintain optimal lung function. The incentive spirometer is a small device that measures how hard you are breathing and gives you a tool to help improve your deep breathing. If you have any lung disease, such as asthma, your respiratory therapist may also use medications that are given through breathing treatments to help open the air pockets in your lungs.


There is a risk of infection any time surgery is performed. Your doctor will take every precaution to prevent infections. You will probably be given antibiotics right before surgery--especially if bone graft, metal screws, or plates will be used. Infections occur in less than 1% of spinal surgeries.

An infection may occur only in the skin incision, or it may spread deeper to involve the areas around your spinal cord and vertebrae. A wound infection that involves only the skin incision is considered superficial. It is less serious and easier to treat than a deeper infection.

A superficial wound infection can usually be treated with antibiotics, and perhaps by removing the skin stitches. Deeper wound infections can be very serious and will probably require additional operations to drain the infection. In the worst cases, any bone graft, metal screws, or plates that were used may need to be removed. Contact your doctor immediately if you suspect that you have an infection. Some indications of infection include:

  • Surgical wound that is red, hot, swollen, and does not heal
  • Clear liquid or yellow pus oozing from the wound
  • Wound drainage that smells bad
  • Increasing pain
  • Fever and shaking chills

Persistent Pain

Some spinal operations are simply unsuccessful. One of the most common complications of spinal surgery is that it does not get rid of all of your pain. Some pain after surgery is expected. If you experience chronic pain well after your operation, you should let your doctor know.

In some cases the procedure may actually increase your pain. Be aware of this risk before surgery and discuss it at length with your doctor. He or she will be able to give you some idea of your chances of not getting the relief that you expect.

Nerve Complications

Nerve Injury

Any time surgery is done on your spine, there is some risk of injuring your spinal cord. This can lead to nerve damage. The nerves in each area of your spinal cord connect to specific parts of your body. This is why damage to your spinal cord can cause paralysis in certain areas and not others; it depends on which spinal nerves are affected.

Spinal Cord Injury

Operations on your spine have some risk of injuring your spinal cord or spinal nerves. This can occur from instruments used during surgery, from swelling, or from scar formation after surgery. Damage to your spinal cord can cause paralysis in certain areas of your body and not others. Injured nerves can cause pain, numbness, or weakness in the area of your body that is supplied by the nerve.

Sexual Dysfunction

Your spinal cord and spinal nerves carry signals from your brain that allow the rest of your body to function and to feel sensation. Damage to your spinal cord and the nerves around your spinal cord can cause many problems. If a nerve is damaged that connects to your pelvic region, it may cause sexual dysfunction.

Implant & Fusion Complications

Delayed Union or Nonunion

A certain number of spinal fusions simply do not heal as planned. This type of problem is called a "nonunion". A nonunion may require a second operation to try to get your bones to heal together. Some fusions will take longer than expected to heal. This type of problem case is called a "delayed union".

Hardware Fracture

Metal screws, plates, and rods are used in many different types of spinal operations as part of the procedure to hold your vertebrae in alignment while the surgery heals. These metal devices are called "hardware". Once your bone heals, the hardware is usually not doing much of anything. Sometimes the hardware can either break or move from the correct position before the surgery is completely healed. This is called a hardware fracture. If this occurs it may require a second operation to either remove or replace the hardware.

Implant Migration

Implant migration is a term used to describe an intervertebral fusion cage that has moved out of place. When this happens, it usually occurs soon after surgery, before the healing process has progressed to the point where the cage is firmly attached by scar tissue or bone growth. If the cage moves too far, it may not be doing its job of stabilizing the two vertebrae in your spine. If it moves in a direction towards your spine or large vessels, it may damage those structures. A problem with implant migration may require a second operation to replace the cage that has moved. Your doctor will check the status of the hardware with X-rays taken during your follow-up office visits.


The term "pseud" means false and "arthrosis" refers to joint. The term "pseudarthrosis" then means false joint. Doctors use this term to describe either a fractured bone that has not healed or an attempted fusion that has not been successful. A pseudarthrosis usually means that there is motion between the two bones that should be healed (or fused together).

There is usually continued pain when the vertebrae involved in a surgical fusion do not heal. The pain may increase over time. The spinal motion can also stress the metal hardware used to hold the fusion, possibly causing them to break. You may need additional surgery for a pseudarthrosis. Your doctor might want to add more bone graft, replace the metal hardware, or add an electrical stimulator to try to get the fusion to heal.

Transitional Syndrome

Your spine behaves like a chain of repeating segments. When your entire spine is healthy, each segment works together to share the load throughout your spinal column. Each segment works with its neighboring segment to share the stresses imposed by movements and forces. When one or two segments are not working properly, the neighboring segments have to take on more of the load. It is the segment closest to the non-working segment that gets most of the extra stress. This means that if one or more levels are fused anywhere in your spine, the spinal segment next to where the surgery was performed begins to take on more stress. Over time this can lead to increased wear and tear on this segment, eventually causing pain from the damaged segment. This is called a transitional syndrome because it occurs at the transition from a normal area of your spine to an abnormal area that has been fused.

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