Adult scoliosis refers to an abnormal sideways curvature of the spine that occurs after skeletal maturity. This condition may be a progression of adolescent idiopathic scoliosis or can develop anew, often due to degenerative changes in the spine, a condition called de novo scoliosis. Surgery is generally considered a last resort, reserved for cases that have failed to respond to comprehensive non-operative management and meet specific structural or functional criteria.
Exhausting Non-Surgical Treatments
Before any surgical intervention is considered, a rigorous trial of non-operative management must be completed, typically for six to twelve months. This initial phase focuses on managing pain and improving the patient’s ability to function in daily life. Physical therapy is a primary component, aiming to strengthen the core muscles that support the spine and improve overall posture.
Specific exercise programs, sometimes focused on scoliosis, are often recommended to help with muscle imbalances and mobility. Pain management involves over-the-counter or prescription medications, such as non-steroidal anti-inflammatory drugs (NSAIDs). For more localized or severe pain, interventional procedures like epidural steroid injections or nerve block injections may be used to target pinched nerves or inflammation.
While bracing is often used for growing adolescents, its role in adults is generally limited to short-term support for pain relief, as it cannot correct the curve in a skeletally mature spine. Only after these conservative treatments have been exhausted without providing adequate relief from pain or functional limitations does the discussion turn toward surgical necessity.
Structural Criteria: Curve Magnitude and Progression
The Cobb angle quantifies the magnitude of the spinal curvature on X-rays. For adults, surgery is typically recommended when the Cobb angle measures 50 degrees or greater. Curves of this magnitude are considered severe and carry a higher risk of continued progression over time, even after skeletal maturity.
Curves larger than 50 degrees may continue to progress at a rate of approximately 0.5 to 1 degree per year, increasing the risk of future complications. Documented progression, such as a noticeable increase in the Cobb angle over successive X-rays, is a significant factor in the decision-making process. In rare instances, particularly with large thoracic curves exceeding 60 degrees, the deformity can start to compromise lung function by restricting the expansion of the ribcage.
Functional Criteria: Intractable Pain and Neurological Deficits
Beyond the size of the curve, the patient’s subjective experience, especially pain and functional limitations, often dictates the need for surgery. Intractable pain, defined as persistent axial back pain or radiating leg pain (radiculopathy) that severely limits daily activities and has not responded to non-surgical treatment, is a strong indicator for surgical intervention.
Scoliosis can lead to spinal stenosis, where the spinal canal narrows and compresses the nerves, causing symptoms like leg weakness, numbness, or neurogenic claudication (pain while walking). The presence of such neurological deficits, including foot drop or significant motor weakness, often necessitates operative treatment. Another functional consideration is sagittal imbalance, where the spine leans forward, forcing the patient to constantly strain their back muscles to remain upright. Correcting this alignment is a major goal of surgery, as this forward lean causes severe fatigue and functional disability.
Understanding the Purpose of Adult Scoliosis Surgery
The goal of adult scoliosis surgery is not to achieve a perfectly straight spine but rather to stabilize the deformity, alleviate pain, and restore proper spinal balance. The procedure typically involves a spinal fusion, where instrumentation like rods and screws are used to hold the spine in a corrected position. Bone graft material is then placed to encourage the fusion of the vertebrae, creating a solid segment of bone over several months.
The operation aims to halt any further progression of the curve and to decompress any nerves being pinched by the deformity. Successful surgical treatment often leads to a significant reduction in radicular pain and an improvement in overall function. Restoration of the sagittal balance—the spine’s alignment from the side—is a major factor for achieving long-term relief and preventing strain on the muscles.