Infantile Scoliosis: Surgery
Growing Rods

Most operations that address spinal deformity in the young child work by stopping growth. This may have unfavorable effects on growth of the thorax, lung development, and size of the trunk. The theory of the growing rod operation is to allow for continued controlled growth of the spine. This is done through the back of the spine. In general, the curve is spanned by one or two rods under the skin to avoid damaging the growth tissues of the spine. The rods are then attached to the spine above and below the curve with hooks or screws. The curve can usually be corrected by fifty percent at the time of the first operation. The child then returns every six months to have the rods "lengthened" approximately one centimeter to keep up with the child's growth. This is usually an outpatient procedure performed through a small incision. Most children will have to wear a brace to protect the instrumentation. When the child becomes older and the spine has grown, the doctor will remove the instrumentation and perform a formal spinal fusion operation. In the past, this procedure had a very high complication rate, most of which were related to the instrumentation (hook dislodgement, rod breakage). Newer techniques are more promising but treatment with growing rods remains a long, difficult therapy for the child.

Before today's sophisticated spinal instrumentation was developed, growing rod surgery was typically done by implanting a single rod, with wires, or a hook at the top and bottom. The complication rate was high, due to many factors, including failure of the rods or fixation. The Dual Growing Rod technique was developed in an attempt to reduce the complications associated with the single rod technique. Similar in principle, the dual rods (two rods anchored to the spine side by side) provide the ability to improve the patient's scoliosis curve at the time of the first surgery. It's important to note that only a limited spinal fusion is performed at the location of the spinal anchors (hooks, screws or a combination of both) to allow for a strong base to attach the rods to the spine. The remaining amount of the spine between these anchors is left alone with the hope that it will grow. Special connectors may be used to link the spinal rods together. It is the lengthening of the spine (by lengthening the rods attached to it) that may allow the spine to grow while the rods control the curve. The rib cage (and the lungs contained inside) may also benefit from the initial correction of the spinal curve as well as the growth of the spine and rib cage over time.

Parents and caregivers must understand that the treatment may last several years; in fact, children have been followed successfully for as long as 7 years or more with this technique. Before surgery, parents and caregivers are counseled on the following treatment program.

• X-rays and a visit to the spine surgeon for a physical exam before and after each surgery to measure spine growth and watch the curve for any changes
• Possible CT scan of the rib cage and spine before the first surgery and once or twice during the treatment to measure lung growth and spinal rotation
• Possible pulmonary function testing (PFTs), if the child is old enough to cooperate, to measure lung function
• Initial inpatient surgery, including limited spinal fusion at the anchor locations, placement of the dual rod spinal implants, and correction of the spinal curve. Length of stay in the hospital averages 5 days
• Short-term bracing after the initial surgery to allow the area where the spine anchors are located to heal
• Periodic lengthenings of the spine (usually as an outpatient surgery under general anesthesia), which are recommended approximately every 6 months to help the rod system continue to control the curve and allow for growth. Rods or connectors may be changed periodically as part of the "routine" maintenance of the rod system.
• Once the child's doctor determines that the maximum benefit of the treatment has been achieved, the doctor will counsel the parents about the final treatment, which is usually a spinal fusion with new rods and anchors to permanently correct and fuse the spine in that corrected position.
• Periodic follow up with x-rays after the last surgery to make sure the treatment program was helpful to that patient.

Parents often worry about the strength of the rods and anchors, especially after the initial surgery. Although it is possible for an anchor to lose its holding power at first, once the anchor area heals, this is usually not a problem. Having the child wear a brace helps to protect the anchors during this delicate period of healing.

It is not uncommon to experience complications such as a broken rod during the treatment period, because young children are allowed to become as active as other children, especially after the brace is removed. Because a large portion of the rod spans an area that is still moving and growing, regular activity can cause anticipated "wear and tear" on the rods leading to breakage. The child may hear or feel the rod break. This is often treated by changing the rods at the next scheduled lengthening. Other complications, such as infection and skin problems, may need additional unplanned surgery.

Because each child's spinal deformity and needs are unique, the pediatric spine surgeon will carefully explain both the benefits and the risks of this surgery to the child's parents. Complications including loss of curve correction and wound infection are discussed with each family. Written material is often provided to help the parents further understand scoliosis and this method of treatment. Parents are encouraged to speak with other parents of children with similar curve types so they can get another parent's point of view, first hand; this can be arranged by the surgeon's office staff.