Adult scoliosis refers to a sideways curvature of the spine, typically measuring 10 degrees or more, in individuals who have reached skeletal maturity. Unlike adolescent idiopathic scoliosis, which often arises during growth spurts, adult scoliosis can either be a progression of a childhood curve or develop de novo due to age-related spinal degeneration. This article clarifies factors, particularly curvature, leading to surgical recommendations for adults.
Understanding Scoliosis Measurement
The Cobb angle is the primary method for quantifying scoliosis, considered the “gold standard” in orthopedic assessment. It is obtained from a standing X-ray of the spine. To determine the Cobb angle, lines are drawn along the top of the most tilted vertebra at one end of the curve and the bottom of the most tilted vertebra at the other end.
Perpendicular lines are then extended from these two parallel lines until they intersect. The angle formed at their intersection represents the Cobb angle, expressed in degrees. A larger Cobb angle indicates a more severe spinal misalignment. While a Cobb angle of 10 degrees or more is generally diagnostic for scoliosis, this is a two-dimensional measurement of a three-dimensional spinal condition.
Cobb Angle Thresholds for Surgery
Surgical consideration for adult scoliosis often begins when the Cobb angle reaches a certain threshold. In adults, a Cobb angle of 45-50 degrees or more typically prompts consideration for surgical intervention. Curves within this range are often classified as severe scoliosis.
These thresholds are significant due to potential for further progression and health impact. Curves greater than 50 degrees may progress more rapidly than smaller curves. For instance, a thoracic curve exceeding 80 degrees can affect lung function, leading to shortness of breath. Surgery is often recommended at these severe levels to prevent such complications.
Surgical thresholds can vary regionally. For example, the United States generally has a surgical threshold around 40-plus degrees for adolescents and 50-plus degrees for adults, while Canada’s is approximately 55 degrees, and Europe’s is around 60 degrees. These variations highlight that while Cobb angle is a key metric, it is part of a broader clinical assessment. The decision to operate is complex, taking into account the curve’s severity and its potential to worsen over time.
Other Factors Influencing Surgical Decisions
While the Cobb angle provides an objective measure of spinal curvature, it is not the sole determinant for adult scoliosis surgery. A patient’s overall clinical picture, including their symptoms and functional limitations, plays a substantial role in surgical decision-making. Persistent, severe back pain unresponsive to non-surgical treatments is a frequent reason for surgery.
Neurological symptoms like weakness, numbness, or radiating pain into the legs (radiculopathy) can indicate a need for surgical intervention. These symptoms often arise from nerve compression due to spinal deformation. Significant functional limitations impacting daily activities, balance issues, or noticeable curve progression over time are important considerations. Spinal balance, the overall alignment of the spine, also guides surgical decisions.
A patient’s general health status, age, and any existing medical conditions are carefully evaluated to assess their ability to tolerate surgery. The decision is highly individualized, considering all these factors to determine if the potential benefits of surgery outweigh its inherent risks.
What Adult Scoliosis Surgery Aims To Achieve
A main objective of adult scoliosis surgery is to improve a patient’s quality of life and prevent further health deterioration. This includes alleviating pain, particularly severe back and leg pain resistant to conservative management. Correcting spinal curvature and decompressing pinched nerves reduces discomfort.
Another aim is to prevent spinal curve progression, which can lead to increasing deformity. Surgery also improves spinal balance and posture, enhancing mobility and allowing patients to resume activities. While complete correction of the deformity is not always the goal, the aim is often to achieve functional improvement and a more balanced spine.
For cases with neurological symptoms, surgery decompresses affected nerves or regions of the spinal cord. Patients considering surgery should discuss anticipated outcomes, potential risks, and realistic expectations with a spine specialist.