Dr.AmitJhala,Sr. Consultant Spine Surgeon,HCG Hospitals, Ahmedabad
The spine, in a healthy body, is an engineering masterpiece. A column of 33 interlocking bones holds us upright, protects the spinal cord, and allows us to bend, twist, and carry the weight of an entire life. In some people, that column deviates, curving sideways into the characteristic S or C shape that clinicians have debated for more than a century. The Indian Orthopedic Association estimates the condition affects 2–3% of the population, roughly 7 to 15 million individuals, yet it remains poorly screened for and frequently diagnosed only after it has progressed beyond the easiest treatment window.
Understanding Scoliosis
Scoliosis is defined as a lateral curvature of the spine of at least 10 degrees, measured using the Cobb angle, the radiographic gold standard since 1948. What distinguishes it from postural asymmetry is its structural nature: the spine doesn’t merely lean but also rotates along its vertical axis, making it a three-dimensional deformity. Curves below 20 degrees are monitored; those between 20 and 40 degrees may be braced; curves above 45–50 degrees in a growing child typically warrant surgical evaluation, carrying risks of progression, pain, and in thoracic curves, compromised lung function.
Types of Scoliosis: Causes, Classification and What Each Means for Treatment
Idiopathic scoliosis is the most common, accounting for approximately 80% of all cases. Idiopathic means the cause is unknown. It is classified by age of onset: infantile (birth to three years), juvenile (three to ten), and adolescent (ten to skeletal maturity). Adolescent idiopathic scoliosis is by far the most prevalent subtype.
Congenital scoliosis originates in embryonic development, vertebral malformations occurring in the first six weeks of gestation create structural asymmetry. A hemivertebra, present on only one side, produces an inherent wedge shape that causes progressive curvature if uncorrected.
Neuromuscular scoliosis develops in children with conditions impairing the muscles or nerves controlling the spine: cerebral palsy, muscular dystrophy, spinal muscular atrophy. Without balanced muscular support, curves can be severe and rapid.
Degenerative scoliosis develops in a previously normal spine, typically after the fifth or sixth decade of life, as a consequence of asymmetric disc and joint degeneration.
Scoliosis in Children: How the Spine Curves During Growth
The critical window is the adolescent growth spurt. Once a curve is established, it tends to worsen during growth and stabilize at skeletal maturity. A 15-degree curve in a ten-year-old with years of growth ahead carries a very different prognosis from the same curve in a 16-year-old nearing the end of their growth period.
Scoliosis in Adults: How Ageing Changes the Spine
In adults, intervertebral discs gradually lose water content with age. When this degeneration occurs asymmetrically, it creates unequal load distribution, setting up a self-reinforcing cycle of joint deterioration, vertebral rotation, and lateral shift. Osteoporosis accelerates the process: even minor compression fractures on one side of a vertebra can introduce the asymmetry that initiates or worsens a curve. A 2025 study in Scientific Reports found that moderate scoliosis raised the odds of severe facet arthropathy at L3–L4 more than six-fold. Unlike the adolescent form, adult scoliosis is defined primarily by pain, chronic back pain, nerve compression, and progressive difficulty walking.
The Screening Gap
Because mild scoliosis rarely causes pain in children, it often goes unnoticed until it has already progressed. US research found that when school-based screening was discontinued, children presented with more advanced curves requiring more intensive treatment. In India, where screening remains inconsistent and largely urban, the first clinical encounter often comes only once a curve has produced pain, deformity, or breathing difficulties, long past the point where conservative management is sufficient.
The question of why some spines curve and others don’t still lacks a complete answer. What is clear is that scoliosis is a multifactorial condition, in children and adults alike, where early detection drastically changes outcomes. That is sufficient reason to screen widely, monitor carefully, and treat on evidence.
