Scoliosis is a medical condition characterized by a sideways curvature of the spine, often appearing as an “S” or “C” shape when viewed from the back. Most cases are idiopathic, meaning the precise cause is unknown, and typically develop during the rapid growth spurts of adolescence. Testing begins with observation and moves toward definitive imaging to confirm the diagnosis and measure the curve’s severity. Early detection allows for timely management, which can prevent the curve from worsening and improve long-term outcomes for those affected.
Recognizing the Early Signs
The initial indicators of scoliosis are visual asymmetries in the body’s posture and alignment. These signs often prompt medical evaluation, even though the condition is generally painless in its early stages. One of the most common observations is uneven shoulder height, where one shoulder appears noticeably higher than the other.
Due to the spine’s rotation, one shoulder blade may also protrude more prominently, creating an asymmetrical appearance. The curvature can affect the pelvis, leading to an uneven waistline or one hip appearing higher. The head may also no longer appear centered directly over the pelvis. Parents might notice these subtle changes when clothes hang unevenly on the body, indicating that a spinal assessment should be performed.
Standard Physical Screening Procedures
The first formal step is a physical examination performed by a healthcare provider, often called the Adam’s Forward Bend Test. The patient stands with their feet together and slowly bends forward at the waist, letting their arms hang down. This screening procedure is effective because it makes the three-dimensional nature of the scoliotic curve more visible.
The examiner views the patient’s back from behind, looking for asymmetry in this flexed position. The primary sign of a structural curve is a prominence or hump on one side of the rib cage or lower back. This prominence results from the vertebrae rotating as they curve sideways, which is a distinctive feature of scoliosis.
To quantify the observed rotation, a small device called a scoliometer, which resembles a level, may be used during the test. The scoliometer is placed on the most prominent part of the trunk asymmetry to measure the angle of trunk rotation in degrees. A reading of 5 to 7 degrees or more generally suggests significant rotation and warrants further, definitive testing with medical imaging.
Confirming Diagnosis Through Imaging
If physical screening suggests the presence of a spinal curve, the next step is to confirm the diagnosis and measure its severity using medical imaging. The standard diagnostic tool is the full-spine standing X-ray, which provides a complete picture of the spinal column while the patient is bearing weight. These images typically include anterior-posterior (AP) and lateral views, allowing doctors to see the curve in both the side-to-side and front-to-back planes.
X-ray images are used to determine the Cobb angle, which is the gold standard measurement for quantifying the curve’s degree. This angle is calculated by drawing lines parallel to the top endplate of the most tilted upper vertebra and the bottom endplate of the most tilted lower vertebra involved in the curve. The angle formed by the intersection of perpendicular lines drawn from these parallels is the Cobb angle measurement.
A formal diagnosis of scoliosis requires a Cobb angle of 10 degrees or greater. Measurements are categorized to guide treatment: mild curves are typically 10 to 25 degrees, while moderate curves range from 25 to 40 degrees. Advanced imaging, such as MRI or CT scans, may be used if the curve progresses rapidly, is atypical in shape, or if an underlying neurological or structural problem is suspected.