Scoliosis surgery straightens the spine by fusing curved vertebrae together using metal rods, screws, and bone graft material. The most common procedure, called posterior spinal fusion, corrects roughly 60% of the curve on average and is typically recommended when the curvature reaches about 50 degrees. The operation is performed under general anesthesia and usually takes several hours, depending on how many vertebrae need to be fused.
What Happens During Spinal Fusion
The surgeon begins by making an incision along the back, directly over the spine or just to either side of it. Once the muscles are moved aside and the vertebrae are exposed, small screws called pedicle screws are placed into each vertebra that’s part of the curve. These screws act as anchor points.
Two metal rods, usually made of titanium or a cobalt-chrome alloy, are then attached to the screws. These materials resist corrosion inside the body and are strong enough to hold the spine in its corrected position. The surgeon carefully contours the rods to match the shape the spine should have, then locks them into the screws. As the rods are secured, they gradually pull the curved vertebrae into better alignment.
With the spine held in its new position, the surgeon places bone graft material along the back of the vertebrae. This graft acts as a biological scaffold. Over the following months, your body grows new bone through and around it, eventually fusing the treated vertebrae into a single, solid segment. The graft can come from the patient’s own body (often small bone chips harvested during the procedure), from a donor bone bank, or from synthetic materials. Research comparing these options has found similar fusion rates for most graft types, though the patient’s own bone remains the standard in many centers.
How Surgeons Protect the Spinal Cord
Straightening a curved spine puts the spinal cord and surrounding nerves at risk of being stretched or compressed. To guard against this, surgical teams use real-time nerve monitoring throughout the entire operation. Small electrodes are placed on the patient’s scalp and limbs before surgery begins. These electrodes continuously send and receive electrical signals through the spinal cord, checking that both sensory and motor pathways are functioning normally.
If the monitoring detects a change in signal strength, the surgeon is alerted within seconds and can adjust the correction before any lasting damage occurs. This system is now routine in scoliosis surgery and has made the procedure significantly safer than it was in earlier decades.
When Surgery Is Recommended
For adolescents with idiopathic scoliosis (the most common type), surgery is generally considered when the main curve measures approximately 50 degrees on X-ray, a measurement called the Cobb angle. Curves below that threshold are usually managed with observation or bracing. The 50-degree mark matters because curves at or above that size tend to continue worsening even after a teenager finishes growing, which can eventually affect lung function and cause chronic pain.
Surgeons also factor in how much growing a patient still has left, how fast the curve is progressing, and whether the curve is causing symptoms like pain or breathing difficulty. A 45-degree curve in a 12-year-old with years of growth remaining may prompt surgery sooner than the same curve in a 16-year-old who is nearly done growing.
Options for Growing Children
Standard spinal fusion permanently locks vertebrae together, which is fine for teenagers who are nearly full height. But for younger children with severe curves, fusing the spine too early would limit how tall they can grow. Two alternatives address this problem.
Magnetically controlled growing rods are titanium rods implanted along the spine with a magnetic component in the middle. During follow-up visits every three to six months, a doctor uses an external remote control to lengthen the rods from outside the body, no additional surgery required. The rods are expanded gradually until the child finishes growing, at which point a final fusion procedure is typically performed.
Vertebral body tethering (VBT) takes a completely different approach. Instead of rods, the surgeon places screw-like anchors into each vertebra on the outer (convex) side of the curve, then connects them with a flexible cord. The tension on the cord slows growth on that side of the spine, allowing the opposite side to catch up naturally over 12 to 24 months. VBT preserves spinal flexibility because no vertebrae are fused, but it works best in patients who are still actively growing and whose curves fall within a moderate range.
How Much Correction to Expect
Spinal fusion for scoliosis typically corrects about 60% of the curve. A patient going into surgery with a 70-degree curve might come out with a curve closer to 28 degrees. The exact result depends on the severity and stiffness of the curve, the patient’s age, and the surgical technique used. Studies of severe scoliosis cases (curves averaging around 107 degrees) have found correction rates between 60% and 62% across different surgical methods, with complication rates as low as 4% when less invasive bone-cutting techniques are used.
The correction is not purely cosmetic. Reducing a severe curve improves rib cage symmetry, which can increase lung capacity. It also redistributes mechanical stress across the spine more evenly, reducing the risk of pain and degeneration in the unfused segments above and below.
Recovery and Activity Restrictions
Most patients spend about three days in the hospital after surgery. By day three, you’re typically eating regular food, walking with minimal assistance, and managing bathroom trips independently. Pain is managed with medication that’s gradually reduced over the first few weeks at home.
Plan on returning to school roughly two weeks after discharge. If you work, most people can go back about a month after surgery, depending on how physically demanding the job is.
The activity restrictions follow a predictable pattern, built around how long the bone graft takes to solidify:
- First 6 weeks: No lifting anything heavier than a half-full kettle. Avoid bending at the waist, twisting motions, and sitting in low or soft chairs. You bend at the knees to pick things up, keeping your back straight.
- 3 months: Gentle swimming and cycling can begin.
- 6 months: Jogging, non-contact sports, and swimming laps are typically cleared. You can start building back to running and activities that involve turning and changing direction.
- 12 months: Competitive and contact sports are usually acceptable, though your surgeon will want to confirm the fusion is solid before giving the green light.
What Life Looks Like After Fusion
The fused section of your spine will no longer bend, which means some loss of flexibility. How noticeable this is depends on how many vertebrae were fused and where. A fusion in the thoracic (mid-back) region, where the spine doesn’t bend much anyway, typically causes less day-to-day limitation than a fusion that extends into the lumbar (lower back) region.
Most people adapt quickly. The unfused segments above and below the fusion compensate for the lost motion, and within a year, many patients report that their movement feels close to normal for everyday activities. The metal hardware stays in permanently unless it causes a problem, and it does not typically set off airport metal detectors with modern screening equipment. Follow-up imaging in the first year or two confirms that the fusion has solidified, and after that, most patients shift to check-ups only as needed.