Spinal Fusion

Most people experience at least one episode of back pain during their lifetime. In the fall of 2004, the office of the U.S. Surgeon General issued it’s first-ever report on the nation’s bone health. It warned that by 2020, one in two Americans over the age of 60 would be at risk for fractures—primarily in the wrist, hip or spine—from osteoporosis or low bone mass. Even today, back pain is second only to colds and upper respiratory infections as the main reason people visit a physician. This pain typically is treated successfully by the patient’s primary care physician. Neurosurgical intervention may be required for patients who fail to respond to this conservative treatment and who are found to have a surgical problem upon subsequent examination.

Herniated discs, spinal stenosis and spondylolisthesis are a few of the most common reasons for pain. Spinal fusion surgery now can stabilize this condition and eliminate the patient’s pain.

In the past, traditional “open” spinal surgery for spinal fusion required the surgeon to make a 4- to 6-inch incision over the area of instability, directly exposing the spinal vertebrae by stripping the overlying muscles away from the spine. The fusion was performed by removing bone grafts from the hip bone and layering the bone graft of the unstable vertebrae. Screws were placed in the affected vertebrae, connecting the rods to provide immediate stabilization of the vertebrae. The bone grafts eventually fuse the two vertebrae together to provide permanent stabilization.

Although this surgery proved successful in achieving stability, there were side effects with the recovery that now can be avoided with spinal fusion surgery. Dr. William S. Reid, Jr. of the UT Medical Center pioneered a new less invasive spinal procedure that allows the lumbar spine to be stabilized with less trauma to the muscle and surrounding tissue. The Sextant™ Rod Insertion System utilizes a mechanical arc device that delivers a rod and screws to rigidly fuse adjoining vertebrae.

Now, neurosurgeons such as Reid are able to perform a spinal fusion through small, ½- to 1-inch incisions, greatly reducing surgical trauma to the back muscles and reducing blood loss to a few ounces. Dramatic progress in this technique has resulted in improved fusion rates, shorter hospital stays and a more active and rapid recovery.

One of the most significant technical advances is frameless stereotactic imaging. Also known as surgical navigation, it combines the use of 3-D X-ray images and a computerized guidance system. These 3-D images are created with a specialized fluoroscope that essentially performs a CT scan in the operating room. The fluoroscope is especially unique because it only is available at UT Medical Center in Knoxville, Tenn. Using the 3-D images and an image guidance system, the surgeon can precisely place bone screws through small incisions.

“The high-resolution TV monitor exposes the surgical site, while we manipulate the precision instruments through an incision that is less than an inch long,” Dr. Reid says. “A computer coordinates images from repeated on-site X-rays and CT scans.”

The star of this high-tech surgery is the Sextant System, which looks and works much like a mariner’s sextant, which places stabilizing rods through the heads of the bone screws to lock the screws together. This again can be performed through a ½-inch incision, minimizing surgical trauma.

Today’s patients have more hope for less pain and shorter recovery time with advanced spinal minimally invasive procedures.