Scoliosis is a condition characterized by a lateral curvature of the spine, often appearing as an S or C shape. Congenital scoliosis (CS) is a rare form of this spinal condition, affecting about one in 10,000 newborns, that is present at birth. This type is caused by structural defects in the vertebrae, which develop abnormally during the earliest stages of pregnancy. In contrast, the most common type, idiopathic scoliosis, has no known cause and typically appears during adolescence.
How the Spine Develops Differently
The structural problems originate from an error during the first six to eight weeks of fetal development when the vertebral column is forming. The developing spine must properly form and then segment into distinct, individual vertebrae. Errors in this process lead to two primary categories of vertebral anomalies that cause the spinal curvature.
The first category is a failure of formation, resulting in a wedge-shaped bone called a hemivertebra. Since only half of the vertebral body forms, this creates an imbalance in the spine’s height, leading to a sharp, angular curve that worsens as the child grows. The second category is a failure of segmentation, where adjacent vertebrae fail to separate and fuse together into a single block. This fused section, known as an unsegmented bar, prevents growth on that side of the spine while the opposite side continues to lengthen, causing a progressive, asymmetrical curvature. The most severe deformities often involve a combination of both types, such as a hemivertebra opposite an unsegmented bar, which creates the greatest potential for rapid progression.
Recognizing and Diagnosing the Condition
Though present at birth, the spinal curve may not be noticeable until a child goes through a period of rapid growth. Visible signs include a noticeable asymmetry of the trunk, such as uneven shoulders, a disproportionate waistline, or one hip appearing higher than the other. When a child bends forward, a doctor may observe a prominence of the ribs on one side, known as a rib hump.
A diagnosis begins with a physical examination but requires specialized imaging to classify the defect. Standard X-rays are the initial diagnostic tool, providing a two-dimensional image that clearly shows the number, location, and type of vertebral malformation. However, a comprehensive evaluation is necessary because of the high incidence of associated anomalies in other organ systems that develop during the same embryonic period.
Up to 25% of children with congenital scoliosis also have genitourinary problems, like kidney or bladder abnormalities, and about 10% have cardiac defects. A mandatory work-up includes an abdominal ultrasound to inspect the kidneys and an echocardiogram to check the heart. Magnetic Resonance Imaging (MRI) is crucial before any surgical intervention to check the spinal cord for issues like tethering or other neurological malformations, which are present in up to 40% of cases. A Computed Tomography (CT) scan provides a detailed, three-dimensional look at the complex bone structure, which is invaluable for surgical planning.
Treatment Approaches
The management of congenital scoliosis is highly individualized and is based on the specific type and location of the vertebral defect, as well as the potential for the curve to progress. For mild deformities or “balanced” defects, where multiple hemivertebrae counteract each other, the primary approach is careful observation. This involves regular clinical check-ups and X-rays during growth spurts to ensure the curve remains stable.
Unlike treatment for idiopathic scoliosis, external bracing is ineffective for congenital curves because the rigidity is caused by a fixed, bony abnormality. Surgical intervention is necessary for curves predicted to progress significantly, often worsening at a rate greater than 10 degrees per year. The goals of surgery are to prevent the curve from worsening, correct the deformity, and allow for continued growth of the chest cavity and lungs.
For localized, severe defects, one surgical pathway involves removing the abnormal bone structure, such as a hemivertebra, and performing a spinal fusion to permanently stabilize the section. For very young children who still require substantial growth, surgeons may utilize growth-sparing techniques like growing rods. These devices control the curve while allowing the spine and torso to lengthen. Modern advancements, such as magnetically controlled growing rods, allow for non-invasive lengthening in a doctor’s office, reducing the need for multiple surgeries.