Medical Health Encyclopedia

This approach also has its advantages and disadvantages:

• Advantages of the Anterior Approach. Because the frontal approach allows the procedure to be performed higher up in the spine than with standard procedures, the patient may have a lower risk for lower-back injury later on. In addition, transfusion rates are much lower with the anterior approach. With increasing experience, the anterior approach is as effective as the posterior approaches.
• Disadvantages of the Anterior Approach. It is a more recent procedure than the posterior approach, and in inexperienced surgeons there is a higher risk for complications than in the more standard posterior approach. One study noted poorer lung function two years after surgery than with the posterior approach, possible because the wide chest incision produces impairs the chest muscles, which can affect lung function afterward. Anterior instrumentation poses a risk for hyperkyphosis (exaggerated outward curvature) and a higher risk for pseudoarthrosis, a painful condition in which a false joint develops at the fusion site. Hardware failure rates may also be higher with the anterior than posterior approach. Increasing experience and newer hardware designs are reducing many of these problems.

The Combined Anterior-Posterior Approach. The combination approach uses an anterior approach first, which allows better correction of the problems. The fusion part of the operation is done with the posterior approach. This is a very long and complex procedure. It appears to be safe, however, and is proving to be useful, even in very young patients, for preventing the crankshaft phenomenon. It may also be used to correct large rigid curves and for specific severe curves in the thoracic spine.

Minimal Access Spinal Approach. Minimal access spinal technologies use a few small incisions and so are far less invasive than the standard so-called open approaches that require wide cuts. The technique uses endoscopy, in which the surgeon makes small incisions and inserts tubes that contain tiny instruments and cameras through the incisions in order to view and execute the procedure. In most cases, the procedure is done in two stages:

• First, an anterior approach is employed to remove disk material and loosen the spine.
• Secondly, a posterior approach is made for fusion and instrumentation.
• Recovery after surgery is rapid. Most patients are out of bed two days after surgery.
• Corrections are reaching 68% in some patients. There is a much more cosmetically appealing result (fewer and smaller scars) with endoscopy, and an easier recovery than with the more invasive approaches.

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The endoscopic procedure for scoliosis is complicated and few surgeons can perform it yet. Currently, it is generally used only for single curves in the upper back or for patients with a curve in the upper back and a curve in the lower back that compensates for it. Some surgeons are now able to operate on areas below the diaphragm, including the lumbar spine. The patients must still wear a brace for three months afterward. Long-term studies are required to determine how outcomes compare to standard procedures.

Complications of All Procedures

Complication rates are high (nearly 10%) with any of these procedures, including the standard Harrington method and the newer Cotrel-Dubousset procedure. Complications for all procedures include allergic reactions to anesthesia and also include:

Bleeding. Standard procedures increase the risk for major blood loss during the procedure. Patients are encouraged to donate blood before the operation for use in possible transfusions. Children sometimes require more than one transfusion following surgery. Researchers are investigating various methods for reducing the need for transfusions:

In one study, erythropoietin (rhEPO) was given to patients before the procedure. RhEPO is a hormone that acts in the bone marrow to increase the production of red blood cells. Patients who were given this hormone, particularly those with idiopathic scoliosis, needed fewer transfusions and spent less time in the hospital than those who did not receive rhEPO.

According to a small Canadian study, tranexamic acid, an agent used to reduce transfusions in heart and knee surgeries, may also decrease transfusions in scoliosis surgery. More studies are needed.

Newer endoscopic techniques are reducing the need for transfusions.

Postoperative Pain. There is always some pain after these operations, requiring intravenous administration of potent painkillers right after the operation (endoscopic procedures may require only mild pain relievers). Of some concern is a study suggesting that the use of NSAIDs, or nonsteroidal anti-inflammatory drugs (e.g., aspirin, Motrin, Advil), for pain relief right after fusion may increase the risk for fusion failure. Until more research is conducted, these common painkillers should not be routinely used right after surgery.

Infection. Infection is always a risk with any operation. One study reported changes in the immune system for about three weeks after surgery, which indicates a greater risk for infection. Researchers recommended being very vigilant for signs of infection, including in the pancreas and urinary tract. Antibiotics, given by injection for two to five days after surgery and by mouth for one to two weeks longer, are also recommended.

Nerve Damage. Patients often worry about neurologic injuries, but the risk is actually very low. In general, nerve injury occurs in 1% of patients, with the risk highest in adults. If neurologic damage occurs, it most often causes muscle weakness. Paralysis is very rare and can be prevented by using monitoring techniques during the operation. Nearly all monitoring procedures use a so-called wake-up test, in which the patient is brought out of anesthesia during or at the end of the procedure and assessed for sensations to be sure no injury has occurred. One simple method is to wake patients up in the middle of their operations and ask them to wiggle their toes. More sophisticated methods measure the electrical activity of the spinal cord; if the monitor indicates a fall in electrical response and possible injury, the surgeon adjusts his techniques to avoid further damage to the spinal cord.

Pseudoarthrosis. If the fusion fails to heal, pseudoarthrosis may develop, a painful condition in which a false joint develops at the site. In one study, patients at higher risk for this complication were teenagers who smoked and heavier adolescents (over 154 pounds) who had hyperkyphosis (hunchback). There may be a higher risk for this with the anterior approach. One study reported that pseudoarthrosis may be undiagnosed and rates may average 20% after surgery, therefore acting as a major contributor to post-surgery pain. More work is needed.

Disk Degeneration and Low Back Pain. Fusion in the lumbar area produces great stress on the lower back and eventually can cause disk degeneration. Loss of trunk mobility, balance, and muscle strength from surgical treatments can also cause lower back pain and chronic problems in future years on. Patients who are surgically treated with fusion techniques lose flexibility and the back muscles may be weakened if they were injured during surgery. In most cases, however, the consequences are mild to moderate.

Other Complications. Other problems that can occur include, but are not limited to, the following:

• Dislodgment of hooks or fracture of a fused vertebra.
• Gallstones.
• Pancreatitis (inflammation of the pancreas). Among adolescents, this complication tends to occur more often among those who are older or who have a lower body mass index.
• Intestinal obstruction.
• Serious postoperative complications that involve the lungs and circulation. These complications are highest in children whose scoliosis is due to neuromuscular problems, such as spina bifida, cerebral palsy, or muscular dystrophy. Such children may need to be managed in an adult intensive care unit.

Click the icon to see an image of gallstones.

Postoperative Therapy

Breathing and coughing exercises to rid the lungs of congestion must be performed shortly after the procedure and continued through the recovery process. The patient is usually able to sit up the day after the operation, and most patients can move on their own within a week. A brace may be necessary, depending on the procedure. With the anterior approach in the upper back, patients may have some trouble with activities involving the arms and hands--such as tying shoes and cutting food. In one study, however, occupational therapy using stretching and strengthening exercises allowed for full resumption of daily activities, including dressing, bathing, and grooming, within three months. Patients are often concerned that surgery will stiffen their backs, but most cases of scoliosis affect the upper back, which has only limited movement, so that patients do not notice much difference. It may take a year or more for muscle strength to return. In some cases, the operation cannot completely correct the curve, and one leg may be shorter than the other. Heel lifts may be used in this case.

Revision (Salvage) Surgery

Patients may need corrective surgery called revision or salvage surgery, usually for one of four different reasons:

• Failure of the previous procedure.
• Curvature progression around the fusion site.
• Disk degeneration.
• Poor posture alignment.

Experimental Surgeries in Young People

Vertebral Body Stapling. Vertebral body stapling may eventually prevent curve progression in some young patients with curves less than 50 degrees. It involves stapling the convex (outer) curve of the anterior spine (the side of the spine facing the chest), which should stabilize and help reduce progression of the inner (concave) curve. The procedure uses a special metal device that is clamp-shaped at body temperature but can be straightened when subjected to cold temperatures and inserted into the spine. When it is warmed up, the staple returns to its clamp shape and supports the spine. Currently this is only being performed at one center.