Scoliosis is an abnormal lateral curvature of the spine that deviates from the body’s midline. This condition is a three-dimensional deformity, including both a sideways bend and a rotational component. Levoconvex scoliosis is a specific classification where the primary curve bends toward the left side of the body. This article explains the specifics of this condition and its diagnosis and management.
Understanding the Specific Curve Direction
The term “levoconvex” provides a precise anatomical description of the spinal curve. The prefix “levo” means “left,” while “convex” refers to the outward-curving side of the arc. A levoconvex curve is one where the spine’s outer edge is directed toward the patient’s left side.
This is considered an atypical curve direction, as the majority of common adolescent idiopathic scoliosis cases are dextroconvex, meaning they curve to the right. A levoconvex curve in the thoracic spine (upper and middle back) may prompt a thorough medical investigation to rule out an underlying neurological cause. Levoconvex curves are more frequently observed in the lumbar spine (lower back) or the thoracolumbar junction.
The curve confirms the condition’s three-dimensional nature, as the vertebrae are shifted laterally and rotated around the central axis. This rotation causes the characteristic rib prominence seen during a physical examination.
Causes and Risk Factors
For approximately 80% of all scoliosis diagnoses, the cause is undetermined, classifying it as idiopathic scoliosis. Even in these cases, certain risk factors are associated with its development and progression. Levoconvex scoliosis, especially when it is found in the thoracic area, is less common than its right-sided counterpart and may signal a need to investigate a possible underlying pathology.
Other known origins include congenital scoliosis, which arises from bone malformations present at birth, such as improperly formed vertebrae. Neuromuscular conditions, like cerebral palsy or muscular dystrophy, can also cause levoconvex scoliosis due to muscle weakness and loss of trunk control.
The condition most often manifests during the rapid growth phase just before or during puberty, typically between the ages of 10 and 15 years. Girls are eight times more likely than boys to have a curve that progresses to a severity requiring medical treatment. A family history of scoliosis also suggests a genetic predisposition, increasing the risk of developing the condition.
How Doctors Measure and Confirm the Diagnosis
The initial step in confirming scoliosis is a physical examination, often including the Adam’s Forward Bend Test. In this test, the patient bends forward at the waist, which makes any asymmetry or rotation of the trunk, such as a rib hump, more visible. If physical findings suggest a spinal curve, full-length X-rays of the spine are necessary to confirm the diagnosis and assess severity.
The primary method for quantifying the curve’s magnitude is the Cobb angle measurement, taken directly from the standing X-ray image. The angle is calculated by drawing lines parallel to the top of the most tilted vertebra above the curve and the bottom of the most tilted vertebra below the curve. The intersection of perpendicular lines extended from these two endplates yields the Cobb angle.
A definitive diagnosis of scoliosis is established when the Cobb angle measures 10 degrees or greater. Doctors use this angle to categorize the severity of the condition. Monitoring the Cobb angle over time is also important, as a change of five degrees or more is considered a significant progression.
Severity Classification
Curves are categorized based on the Cobb angle: Mild curves are 10 to 25 degrees, moderate curves range from 25 to 50 degrees, and severe curves exceed 50 degrees.
Management Options
Treatment for levoconvex scoliosis follows a structured protocol based on the patient’s skeletal maturity and the severity of the measured Cobb angle.
Observation
For mild curves (typically less than 25 degrees), the standard approach is observation. This involves regular physical examinations and X-rays, often every six months, to monitor for any signs of progression while the patient is still growing.
Bracing
If the curve is moderate (usually between 25 and 45 degrees in a growing patient), bracing is often recommended to prevent the curve from worsening. A custom-fitted spinal orthosis, such as a Boston brace, is worn for many hours a day, generally between 16 and 23 hours. The goal of bracing is to halt progression until skeletal maturity is reached, not to correct the existing curve.
Surgery
Surgical intervention is typically reserved for severe curves, usually those that have progressed beyond 45 or 50 degrees. The most common procedure is a posterior spinal fusion. Metallic instrumentation, such as rods and screws, is used to straighten and stabilize the spine. This hardware is fused with bone grafts to create a single, solid column, permanently correcting the deformity and preventing further progression.