Scoliosis is a three-dimensional spinal deformity where the spine curves sideways and often includes a rotational component. When the curvature becomes severe, typically exceeding 40 to 50 degrees, surgical intervention may be considered to prevent further progression and to correct the existing curve significantly. The primary goal of this complex surgery is to restore spinal alignment and stabilize the spine permanently to ensure better long-term function and balance.
Deciding on the Surgical Approach
The surgical approach depends on a careful assessment of several patient-specific factors. A primary determinant is the patient’s age and, more precisely, their skeletal maturity, which indicates how much growth remains. The magnitude of the curve, measured by the Cobb angle on an X-ray, is a strong indicator, with curves over 45 to 50 degrees generally warranting surgical consideration in adolescents.
The curve’s location (thoracic or lumbar spine) also influences the optimal surgical strategy. Curves that continue to progress rapidly despite non-surgical treatments are typically prioritized for intervention. For adolescents who have largely finished growing, the objective is often a definitive correction and stabilization through fusion. In contrast, treatment for very young children still in a major growth phase focuses on growth-sparing techniques to control the curve while allowing the torso and lungs to continue developing.
The Mechanics of Spinal Fusion
Spinal fusion is the most common and definitive procedure for correcting severe scoliosis, mechanically working to straighten the spine and then lock it into the corrected position. The process begins with preparation and exposure, typically involving a posterior approach where an incision is made to access the vertebrae. Muscles are moved aside to reveal the affected spinal column.
The next stage involves instrumentation and correction, where the surgeon places anchor points, such as pedicle screws and hooks, into the vertebrae above and below the apex of the curve. Two customized metal rods are then attached to these anchor points. The surgeon manipulates these rods, applying force through techniques like derotation and translation, to carefully straighten and realign the spine’s three-dimensional deformity. The rods provide immediate mechanical stability, holding the corrected alignment in place.
The final and most defining step is fusion, which provides permanent stability. Small pieces of bone graft (autograft or allograft) are placed along the corrected segment of the spine. Over the next several months, this bone graft encourages the vertebrae to grow together into a single, solid bone mass, which permanently stabilizes the spine and prevents the curve from worsening.
Understanding Non-Fusion and Minimally Invasive Techniques
For specific patients, alternatives to traditional fusion offer the benefit of preserving spinal flexibility.
Vertebral Body Tethering (VBT)
Vertebral Body Tethering (VBT) is a growth-sparing procedure typically used for younger patients who have significant growth remaining. The surgeon accesses the spine through a less invasive anterior approach, often using small incisions on the side of the chest or abdomen. Metal screws are placed into the vertebrae on the convex side of the curve, and a strong, flexible cord, or tether, is attached to these screws and placed under tension. This tether works by applying a constant, gentle pressure to the outer side of the curve, slowing growth on that side. The continued, unrestrained growth on the concave side of the curve gradually pulls the spine into a straighter alignment, a process known as guided growth.
Growth Rods
Another method for pre-pubescent children is the use of Growth Rods, such as the magnetically controlled growing rods (MAGEC system). These rods are surgically implanted and secured to the spine above and below the curve. They are designed to be lengthened non-surgically in a doctor’s office using an external remote control, avoiding the need for repeat operations required by older systems. This allows the spine to lengthen as the child grows while the rods continue to control the scoliotic progression until the child is old enough for a definitive fusion.
Minimally invasive approaches, utilizing smaller incisions and specialized tubes, are now used for some fusion surgeries, though the fundamental mechanics of instrumentation and bone fusion remain the same.
Post-Operative Care and Recovery Timeline
The recovery process begins immediately after surgery, with patients typically spending three to seven days in the hospital for close monitoring and pain management. During the initial days, a patient-controlled analgesia (PCA) pump is often used to manage post-surgical discomfort. Physical therapists assist the patient in achieving early mobilization, which includes getting out of bed and walking short distances as soon as the first day after the operation.
During the intermediate recovery phase, which spans the first three to six months, patients must adhere to specific restrictions to protect the healing fusion site. Activities such as lifting anything heavier than a few pounds, excessive bending, and twisting of the torso are strictly prohibited. Most patients are able to return to school or desk-based work within three to six weeks.
The long-term outlook is focused on the complete biological fusion of the bone segments. While the metal rods provide immediate mechanical support, the fusion is generally considered solid after six months to one year. At this point, the surgeon typically clears the patient to gradually return to full activity, including contact sports and other high-impact activities.