09 Nov Spinal Fusion Surgery – Traditional versus Minimally Invasive
Spinal fusion surgery is used to unite (fuse) one or more vertebrae (irregular spine bones) together. With this procedure, bone grafts are used to join the vertebrae.
Why is spinal fusion done?
To understand the purpose of spinal fusion, you need to understand the components of the spine. The spine is made of several irregular shaped bones called vertebrae (singular – vertebra). Intravertebral discs separate these bones and act as cushions between them. The discs are composed of a soft, gel-like center (called the nucleus) and tough, fibrous outer layers (called annulus). The discs are quarter-sized and filled with a watery substance. The spinal cord runs through a canal formed by the bones, and spinal nerves branch off the cord to supply the body trunk and extremities (arms and legs). When a disc is problematic, and the irregular bones have shifted, pain can occur. Spinal fusion surgery is used to relieve back pain associated with disc and bone problems.
Why do people need spinal fusion surgery?
The main reason for spinal fusion surgery is a vertebral fracture, but not all spine fractures require surgery. When the fracture causes nerve compression or presses on the spinal cord, surgery is generally required. Other reasons for spinal fusion surgery include severe spinal arthritis, scoliosis, degenerative disc disease, spinal stenosis, and spondylolisthesis.
How common is back pain?
Common causes of back pain include lumbar spinal stenosis, spinal arthritis, and degenerative disc disease. In a recent study, researchers found that lumbar spinal stenosis increased in prevalence with age, affecting 22% of persons under age 60, and 47% of those over age 60. Degenerative disc disease and facet arthritis both also increase with aging. By age 80 years, around 70% of people suffer from these conditions.
What is traditional spinal fusion surgery?
Called ‘open surgery,’ traditional spinal fusion surgery involves a long incision (5-6 inches) at the area for spinal fusion. This incision allows the surgeon to retract muscles and soft tissue so the spine can be viewed. A retractor device is used so the doctor can view the spine and remove damaged and disease discs and bone. With this approach, the surgeon can easily see to place bone graft materials, screws, and cages along the bones to stabilize the spine. One of the main drawbacks of traditional open spinal fusion is that the retraction of muscle tissue can cause damage, causing a longer recovery time and back pain after surgery.
How is the minimally invasive spinal fusion surgery different?
With the minimally invasive spinal fusion surgery, the surgeon avoids making a long incision, which eliminates damage to the muscles and other surrounding tissues. For most people, this results in less pain after spine surgery and a faster recovery. With this procedure, the surgeon makes several small incisions along the back over the area of damaged bone and/or discs. Small tubular retractors are inserted through the small incisions to create a tunnel in the area where damage exists. The retractor holds the muscles apart and is kept in place for the surgery.
The surgeon uses fluoroscopy (x-ray guidance) to view the spine during the surgery, and a small operating microscope allows the doctor to view through the retractor. Using small instruments that fit though the retractor, disc material and bone are removed as necessary, and bone grafts, rods, and screws are used to fuse the spinal bones. After making all changes, the retractor is removed so the muscles can return to usual position.
Hicks GE, Morone, N, & Weiner DK (2009). Degenerative Lumbar Disc and Facet Disease in Older Adults: Prevalence and Clinical Correlates. Spine, 34(12), 1301-1306.
Kalichman L, Cole, R, Kim DH, et al. (2013). Spinal stenosis prevalence and association with symptoms: The Framingham Study. Spine Journal, 9(7), 545-550.