What is scoliosis and why is scoliosis surgery required?

The Spine is the backbone of the body. It naturally curves a little. This allows us to walk, move and balance ourselves properly. But some people have a spine that curves too much to one side. This condition is called scoliosis. In most cases, especially in children and adolescents, the cause of scoliosis is unknown and scoliosis is referred to as idiopathic scoliosis.

Scoliosis usually has no symptoms. In severe cases, the body looks asymmetrical with uneven hips or shoulders. Severe scoliosis may also cause backache and could contribute to other health problems.

To diagnose scoliosis your doctor will do a physical examination. The doctor will also order some diagnostic tests such as X-rays, a Computed Tomography (CT) scan and/or Magnetic Resonance Imaging (MRI) to determine the actual curving of the spine. If your doctor considers that your curve is mild they may prescribe back braces to prevent further curving. However, if the curve is more than 45 degrees, your doctor may recommend corrective spinal surgery.

What is the anterior approach for scoliosis surgery?

The goal of scoliosis surgery is to both reduce the abnormal curve in the spine and to prevent it from progressing further and getting worse. To achieve this, a spinal fusion is performed to fuse the vertebrae, in the curve to be corrected. This involves placing bone graft or bone graft substitute in the intervertebral space between the two vertebrae. Instrumentation such as rods and screws are also used to realign and stabilize the vertebrae until the graft heals and fuses the two vertebrae together.

There are several approaches for scoliosis surgery. The choice of approach depends on a number of factors such as the type of scoliosis, location of the curvature of spine, ease of approach to the area of the curve and the preference of the surgeon.

Anterior approach is one of the approaches to perform scoliosis surgery. In this approach, the spine is accessed through an incision made in the front or anterior side of the body over the chest wall or abdomen. Anterior approach is generally used when the curvature is in the middle spine (thoracolumbar spine) or lower spine (lumbar spine) and the curve is severe. It is also often used for rigid curve correction in adults.

How is an anterior spinal surgery performed?

For an anterior spinal fusion, you will be first sedated and then general anesthesia is administered. You will be rolled onto your side with the operative side facing up (lateral decubitus position).

• An incision is made on the side over the chest wall or abdomen depending upon the location of the curve in the spine.
• To reach the spine, the lung is deflated and even a rib is removed. In case of curves in thoracolumbar spine and lumbar spine the diaphragm is also detached.
• Disc material is removed from between the vertebrae involved in the curve. Removal of the disc material increases the flexibility of the curve and also provides a large surface area for spinal fusion.
• Instrumentation is then used to produce correction of the spine. This involves placing the screws at each vertebral level involved in the curve. A single or double rod is then attached to these screws at each level. A combination of compression along the rod and rotation of the rod is performed to achieve proper correction of the spinal deformity.
• The bony surface between the vertebral bodies is roughened and bone graft or bone graft substitute is packed into the space between the vertebral bodies to promote fusion. The source of bone graft may include removed rib, the crest of the pelvis or allograft bone.
• Finally the incision is closed. If the surgery involves the chest cavity a chest tube will be placed through the side of the chest to keep your lung expanded after the surgery.

The whole procedure usually takes several hours.

What are the advantages of anterior approach over other approaches?

The main advantage anterior approach provides is that fewer vertebral bodies need to be fused for curve correction using this approach. This saves motion at the other segments and prevents loading all the stress on just a few motion segments reducing the risk for developing back pain and arthritis later. This is very crucial if the fusion is for lower back curves and goes below L3. Anterior approach also allows for a better reduction of the curve and has a more favorable cosmetic outcome.

However, anterior approach can only be done for thoracolumbar curves. Scoliotic curves in most patients lie in the thoracic spine. Anterior approach is also more difficult than the traditional posterior approach.

How long does the recovery take?

The spine looks much straighter soon after the surgery but some curve will still be there. Spinal bones take a minimum of 3 months to fuse together. However, complete fusion usually takes one to two years.

What are the potential risks and complications of the procedure?

Scoliosis surgery is a major surgery. All attempts are made to reduce the chances of any risks or complications of this surgery. Still, complications may occur in a few patients. Complications of scoliosis surgery may include paraplegia, excessive blood loss, infection and failure of the spine to fuse. Rarely, cerebrospinal fluid leakage or instrumentation problem such as breaking of rods or dislodging of hooks and screws may also occur.