Though scoliosis is often associated with children, adults can have it too. Adult forms of scoliosis often have a degenerative element. That is, scoliosis develops due to wear and tear of spinal structures that cause the spine to tilt. When this occurs, it’s known as adult degenerative scoliosis. In other cases, the scoliosis begins in childhood and progresses into adulthood (often made worse by spinal degeneration)—this is called adult idiopathic scoliosis.
Symptoms associated with adult scoliosis are often initially managed with nonsurgical therapies; such as medications, physical therapy and/or injections. However, when symptoms don’t respond to nonoperative treatment, or when the spinal deformity is severe or getting worse, spine surgery may become necessary.
The general principles involved in surgery on adult patients with scoliosis, which will be reviewed in this article, are:
Nerve compression causing pain, numbness, tingling, or weakness in the legs is commonly associated with adult scoliosis. During surgery, there are a variety of techniques available that can be used to reduce nerve compression, but may be broadly grouped into direct and indirect decompressions.
Direct decompression involves looking right at the nerve and removing bone, ligaments, and/or disc material causing compression. Microdecompression with laminotomy / foraminotomy and laminectomy are examples of these techniques. Because these techniques remove bone and ligament, there is some concern that when used alone in the setting of adult scoliosis, the scoliosis or deformity can worsen and cause recurrent symptoms. For that reason, correction and fusion of the spine are often used along with these techniques, as discussed below.
Indirect decompression relies on correction of the scoliosis or deformity and/or increasing the space between the vertebral bones to open up more space for the nerves, without necessarily looking right at the nerves. These techniques also require fusion of the bones together in an improved alignment, as discussed further below.
Improvement of spinal alignment can be accomplished by a variety of techniques. While it is desirable to reduce the amount of scoliosis (side-to-side curve), it is probably more important that any loss of lordosis or kyphosis (front-to-back curves) is corrected to keep the patient standing upright.
With progressively severe and rigid or stiff curves, more complex maneuvers—with associated increased risks—may be required to allow correction of the deformity.
An osteotomy involves cutting into and removing spinal bone to loosen the spine and allow it to be moved into a more normal position. In the simplest form, an osteotomy may involve removing only part of the small facet joints along the back of the spine. In more complex osteotomies, bone is removed across the entire spine—essentially cutting a spinal bone in half. These more complicated procedures are called pedicle subtraction osteotomies—in which a wedge of bone is removed from the spine—and vertebral column resection—in which an entire vertebral body is removed from the spine.
After correction of the scoliosis, a spinal fusion is performed to prevent adult scoliosis and deformity from recurring. In simple terms, a spinal fusion “fuses” two or more spinal bones (vertebrae) into one solid bone. Fusion eliminates the motion between the vertebrae, but maintains the overall corrected spinal alignment.
The process of spine fusion involves stabilizing the bones and placing material around the bones to promote bone healing. The stability between the vertebrae is achieved by implanting instrumentation. Instrumentation generally involves putting screws into the bones and connecting them with metal rods. Cages may also be placed in the empty disc space between the vertebrae.
Your surgeon will also insert material to promote healing of the bone between the vertebrae. Morselized pieces of bone—called bone graft—are placed around the vertebrae and instrumentation. Two types of bone graft are autograft (your own bone) and allograft (cadaver bone). In addition to bone graft, there are other commercially available substances that may be used to promote bone healing. Over time, the bone grows from one vertebra to another in a process similar to a fracture healing. The process of fusion is complete when all the bones included in the fusion have grown together, which can take several months to occur.
Spinal fusion is a common type of spine surgery—not only for scoliosis but for a host of other spine conditions.
Moving Forward from Adult Scoliosis Surgery
The duration and ease of your recovery will depend on the type of scoliosis surgery you have, but your surgeon will likely recommend physical therapy to help strengthen your muscles and improve flexibility. A key to long-term success after scoliosis surgery is to follow your surgeon’s instructions. So, ask questions if you’re not clear how to move forward after the procedure. With time and dedication, pain associated with adult scoliosis can be improved, and patients can achieve significant improvement in their quality of life.