Scoliosis is a condition characterized by a sideways curvature of the spine, often appearing as an “S” or “C” shape rather than a straight line. While the spine naturally has slight front-to-back curves, scoliosis involves an abnormal curve in the side-to-side plane. The severity of this spinal curvature is measured in “degrees,” and this measurement is important for understanding the condition’s impact and guiding its management. Most cases are mild and may not cause noticeable symptoms, but more severe curves can affect posture and, in rare instances, breathing and movement.
Measuring the Curve
The standard method used to quantify scoliosis is the Cobb angle. This measurement is obtained from an X-ray of the spine, taken with the patient standing. To calculate the Cobb angle, a healthcare professional first identifies the two most tilted vertebrae at the top and bottom of the spinal curve. These are known as the end vertebrae.
Next, a line is drawn parallel to the upper edge of the top end vertebra and another line is drawn parallel to the lower edge of the bottom end vertebra. Perpendicular lines are then drawn from each of these parallel lines. The angle formed where these two perpendicular lines intersect is the Cobb angle, expressed in degrees. This value represents the curve’s magnitude.
Classification of Scoliosis Severity
Scoliosis is classified into different severity levels based on the Cobb angle measurement. A curve measuring less than 10 degrees is considered a minor spinal asymmetry and not classified as scoliosis. Mild scoliosis is diagnosed when the Cobb angle is between 10 and 25 degrees. These curves often present with subtle signs, making early detection challenging.
Moderate scoliosis is characterized by a Cobb angle ranging from 25 to 40 degrees. At this stage, postural changes become more noticeable, and the curve may progress more significantly. Severe scoliosis is indicated by a Cobb angle greater than 40 or 45 degrees.
Treatment Considerations Based on Degree
The measured degree of scoliosis significantly influences treatment decisions and management plans. For mild curves, observation is often the primary approach. This involves regular monitoring with physical exams and X-rays, every 4 to 6 months, to track any progression of the curve. The goal of observation is to ensure the curve does not worsen, especially in growing individuals.
For moderate curves, bracing may be recommended. Bracing aims to prevent the curve from progressing further, particularly in adolescents who are still growing. The brace is designed to apply external forces to the spine, helping to maintain its alignment and ideally prevent the need for surgery.
Surgical intervention is considered for severe curves, or for curves that continue to progress despite other treatments. The most common surgical procedure is spinal fusion, which involves joining vertebrae together to correct the curve and stabilize the spine. The decision for surgery also considers factors such as the patient’s age, skeletal maturity, and potential impact on lung function for very large curves.