The human spine is composed of stacked bones, or vertebrae. When the spine develops an abnormal sideways curvature and rotation, the condition is known as scoliosis. Dextroscoliosis describes a specific pattern of this spinal deviation, requiring a distinct approach to diagnosis and management. This article explains this particular form of spinal curvature, its origins, measurement, and treatment.
Defining the Rightward Curve
Dextroscoliosis is a subtype of scoliosis characterized by a spinal curve that bows toward the patient’s right side. This right-sided curve is the typical pattern, particularly in the thoracic, or middle, section of the spine. A diagnosis of scoliosis requires a measurable sideways curve of at least 10 degrees, known as the Cobb angle, accompanied by a rotational element of the vertebrae. When the curve bends to the patient’s left, it is known as levoscoliosis. A left-sided curve in the thoracic spine is less common and may raise suspicion of an underlying condition requiring further investigation.
Identifying the Underlying Causes
The specific cause of dextroscoliosis is frequently unknown, a classification known as idiopathic. This accounts for 80% to 85% of all scoliosis diagnoses, meaning they lack a single, identifiable cause. This form most often develops during adolescence, coinciding with a period of rapid skeletal growth. While the exact trigger remains unclear, genetic factors may play a role due to the tendency for the condition to appear in families.
Known Causes
Cases with a known cause are categorized by their origin. Congenital scoliosis arises from malformed vertebrae that develop improperly before birth. Neuromuscular scoliosis is secondary to conditions affecting the nerves and muscles, such as cerebral palsy or muscular dystrophy. These conditions result in a loss of muscle support around the spine, leading to curvature. Degenerative scoliosis occurs in older adults due to age-related wear and tear on spinal discs and joints, causing the spine to collapse or curve over time.
Diagnosis and Measuring Severity
The confirmation of dextroscoliosis begins with a physical examination, which may include the Adams forward bend test to check for spinal asymmetry. If a curvature is suspected, a full-length, standing X-ray of the spine confirms the diagnosis. This imaging allows for the precise measurement of the curve’s magnitude, which assesses severity and guides treatment.
The primary metric used to quantify the spinal deviation is the Cobb angle, measured directly from the X-ray image. To calculate this angle, a line is drawn along the top of the most tilted vertebra at the upper end of the curve, and another line is drawn along the bottom of the most tilted vertebra at the lower end. The angle at which perpendicular lines intersect is the Cobb angle, expressed in degrees.
The Cobb angle is the fundamental tool for classifying severity. Curves between 10 and 24 degrees are considered mild, while those measuring 25 to 49 degrees are classified as moderate. Curves of 50 degrees or greater are considered severe.
Management Approaches
Management for dextroscoliosis is tailored to the patient’s Cobb angle measurement and their remaining skeletal growth. Progression is more likely in growing individuals, so treatment decisions depend heavily on skeletal maturity.
Observation
For mild curves (less than 25 degrees), the standard approach is observation. This involves regular monitoring with physical exams and X-rays every four to six months to ensure the curve is not progressing.
Bracing
If the curve is moderate (25 to 45 degrees) in a growing patient, bracing is recommended to halt progression. Bracing is an effective, non-surgical method worn daily until skeletal maturity, preventing the curve from worsening.
Surgery
Surgical intervention is reserved for severe curves, typically those exceeding 45 to 50 degrees, especially if progression continues despite bracing. The most common procedure is spinal fusion, where multiple vertebrae are permanently joined together. Metal rods and screws are used to correct the curvature and stabilize the spine.