Infantile Idiopathic Scoliosis
Infantile scoliosis is classically defined as scoliosis that is first diagnosed in a child between birth and 3 years old. Congenital scoliosis (malformed and/or connected vertebrae) is also diagnosed during this period. However, these curves are not included in the infantile idiopathic scoliosis category. Many infantile curves will resolve without treatment. Those that do not resolve can be difficult to manage. Your scoliosis specialist may suggest a magnetic resonance imaging (MRI) study to determine if there are any abnormalities of the spinal cord or spinal column. The study is more difficult in small children because sedation or even general anesthesia may be necessary to relax the child enough to obtain good images. Many infantile curves are left-sided curves in the thoracic (chest) area – in contrast to the right-sided curves more common in adolescents. It is more common in boys than girls. In some patients, there is an increased association with hip dysplasia, mental retardation, and congenital heart disease. Many other infants are health and normal and simply have a small curvature of the spine.
When scoliosis occurs at a very young age, there are several important implications for management and treatment. For example, a 60o idiopathic curve (cause of scoliosis unknown) in a teenager is typically managed quite successfully with a posterior instrumented fusion. The same 60o curve in a 2-year old is managed very differently. The 2-year old needs many years to maximize their trunk height and lung size. A fusion in a young child would prevent further growth of the instrumented segment. Furthermore, depending on the type of instrumentation used, the anterior spine may continue to grow leading to “crankshaft phenomenon”. In this situation, the scoliosis continues to progress despite the posterior fusion. For this reason, other treatments have been developed for the management of early onset scoliosis. These techniques take into account the growth of the spine as well as the growth of the rib cage and lungs. If implants are necessary, multiple expansions or lengthenings may be necessary (usually twice per year) to keep up with growth in the young spine.
The most basic way to monitor the curves is through standing X-rays. X-rays to day have a small fraction of the radiation they did several years ago. Your spine surgeon will probably want to see your child every four to six months and have new front- and side view X-rays made. They will then measure the curves and compare them with prior films. It is ideal to have all the X-rays done at your scoliosis surgeon’s office so that he/she can obtain the proper studies, and compare them properly. Doctors may obtain special bending radiographs to assess the flexibility of the curve(s).
Special studies as MRI or CT are sometimes necessary to look for abnormalities in the bones or pressure on the nerves. An MRI study is often done to evaluate the spinal cord and find any abnormalities that may be causing the scoliosis or kyphosis (round back). In children, sedation or general anesthesia is usually necessary to relax the child. A CT scan may be necessary to rule out bony anomalies.
Casting / Bracing
Figure 1: Casting
If the curve is progressive, your doctor may want to place your child in a cast or brace. This is contingent upon the flexibility of the curve as determined by the bending radiographs. Rarely does a brace permanently correct scoliosis. Instead, the goal is to allow the child to grow before a more definitive procedure (surgery) is done. It must be re-emphasized that the purpose of the brace is to slow the inevitable progression of the curve, not to permanently correct the curve.
Due to their size, small children often respond better to casting – converting to bracing when their torso is large enough (see Figure 1). Placement of the cast on the child may require general anesthesia to increase flexibility of the curve and make the child more confortable during the application. The case is generally changed every six months . Casting can offer superior curve management at the cost of its inconvenience (it cannot be removed for bathing).
The brace that your doctor prescribes may depend on your child’s age and the center you visit. The Kalabas brace has several straps that are applied over the shoulder and bend the child in the opposite direction of the curve (Figure 2A). The Wilmington brace is a custom-molded thoracolumbar orthosis that molds to push and correct the curve (Figure 2B-C). The Boston brace is similar, but uses pads inside the brace to push the curve. This is the most common used in older children and adolescents (Figure 2D). The Milwaukee brace, one of the first braces developed for scoliosis treatment, is rarely used today due to its design, which can include an extension to the chin (Figure 2E). Your doctor will probably recommend that your child wear the brace full time. Braces are generally removed for bathing and special occasions. As your child grows, new braces will need to be made, approximately every 12-18 months.
Bracing may not be effective in every child for various reasons. If the curve is rigid, or the apex (midpoint) is too high (above the level of the armpits), bracing will do little good. Braces also have a more difficult time controlling kyphosis (round back) and lordosis (sway back). Since most braces work on the curve via pressure on the rib cage, concern exists over the effect that the brace has on the rib cage and subsequent development of the lungs. Children with reflux, feeding tubes, and colostomies may have difficulty wearing a brace, but modifications can usually be made (Figure 2C).