Scoliosis - Surgery

Instrumentation

Harrington Procedure. Until ten years ago, the standard instruments used in fusion procedures were those of the Harrington procedure, first developed in the 1960s:

To support the fusion of the vertebrae, the surgeon uses a steel rod, extending from the bottom to the top of the curve. (More than one rod may be used depending on the type of curve and whether kyphosis is present.)
The rod is attached by hooks that are suspended from pegs inserted into the bone.
Similar to changing a tire, the steel rod is jacked up and then locked into place to support the spine securely. The surgeon is then ready to fuse the vertebrae together.
After this operation, patients are required to wear a full body cast and lie in bed for three to six months until fusion is complete enough to stabilize the spine.
After one to two years, the steel rod is not really necessary, but it is almost always left in place unless infection or other complications occur.

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The Harrington procedure is very difficult to undergo, particularly for young people, and although the operation can achieve a correction of the curve of over 50%, studies have reported a loss in this correction of between 10% to 25% over time. The procedure does not correct the rotation of the spine and, therefore, does not improve an existing rib hump that was caused by the rotation. The operation does not interfere with normal pregnancies and deliveries later in life.

Certain complications may occur from this procedure:

About 40% of Harrington patients have a condition called the flat back syndrome, because the procedure eliminates normal lordosis (the inward curving of the lower back). Flat back syndrome from the Harrington procedure does not cause any immediate pain. In later years, however, the disks may collapse below the fusion, making it difficult to stand erect, and the condition can cause significant pain and emotional distress.
Studies have reported that five to seven years after their surgery, between a fifth and a third of patients who had the Harrington procedure experienced low back pain. (In one study, only 3% had experienced back pain before surgery.) In such cases, however, the pain was not severe enough to interfere with normal activities and did not require additional surgery.
In children younger than 11 whose skeleton is immature and who have the Harrington procedure, there is a fairly high risk for a specific curve progression called the crankshaft phenomenon. This condition occurs after the procedure when the front of the fused spine continues to grow. The spine cannot grow longer, so it twists and develops a curvature. In one study that followed patients for between five and 16 years, crankshaft curve progression was moderate, however, with the Cobb angle averaging 9 degrees and rotation averaging 7 degrees.