The spine is composed of 33 bones, individually known as the vertebrae. The spine is divided into five main regions, including: cervical (neck), thoracic (middle back), lumbar (lower back), sacral (back of the pelvis) and coccygeal (tailbone).
In addition to providing support to the body, the spine protects the spinal cord and nerves that transmit signals between the brain and the rest of the body. Once the cord reaches the lumbar spine, the nerve roots branch off and exit to the lower portion of the body.
Spinal degeneration occurs as a natural part of the aging process and can cause areas of the vertebrae to weaken and become unstable and nerve roots to become pinched. When this occurs, the vertebrae can be healed (fused) together to restrict movement and stabilize the spine.
Every year, 65 million Americans report suffering from lower back pain, and approximately 80% of Americans will suffer from back pain at some point in their lives. Lower back pain is often caused by a natural degeneration of the spine that occurs with aging. In severe cases, this degeneration can lead to instability in certain areas of the spine and cause the nerves around the spine to become pinched. A pinched nerve may lead to such symptoms as weakness, numbness, burning and tingling that radiate down the legs.
Conservative methods are the first line of treatment for back pain, and include medication, physical therapy, and steroid injections. However, if conservative treatments are unsuccessful, a surgical solution may be necessary. One of the most effective techniques to stabilize the spine is a spinal fusion procedure.
Reasons for Spinal Fusion Surgery
More than 250,000 lower back, or lumbar, spinal fusion surgeries are performed annually in the United States to treat conditions involving back pain caused by spinal degeneration. Some of the conditions that may contribute to spinal degeneration include:
- Spondylolisthesis, which occurs when a vertebrae slips forward over the vertebrae below
- Spinal fractures due to osteoporosis
- Lumbar spinal stenosis, which involves overgrown bone and tissue pressing on nerves in the spinal column
- Degenerative disc disease, which is the gradual wear and tear on spinal discs due to aging
The Spinal Fusion Procedure
During spinal fusion surgery, two or more adjacent spinal vertebrae are fused, or healed, together to restrict movement and decrease the pain caused by instability. The surgeon will typically use metal implants such as pedicle screws and rods that provide a source of bracing and support to immobilize the diseased vertebrae. Additionally, the surgeon will implant a substance called bone graft at the fusion site to help promote the growth of new bone, which fuses the vertebrae together.
For more advanced cases of spinal degeneration, the surgeon may need to implant an interbody device between the vertebrae. The interbody device provides a greater level of stability to the area as the spinal fusion takes hold. Interbody devices restore spacing between the vertebrae and serve as a holding chamber for a substance called bone graft that helps the body create new bone.
Minimally Invasive Fusion Surgery
New advances in technology have provided a less invasive option than traditional surgery for certain patients. Minimally invasive fusion surgery, or MIS fusion, has been shown to be very successful in improving a patient’s quality of life by effectively treating debilitating back and leg pain. MIS fusion involves the use of smaller implants that require smaller incisions than those required for traditional spinal fusion procedures. This minimizes muscle tissue damage, reduces scarring and limits blood loss. MIS fusion offers patients a less painful and quicker recovery, enabling them to return to work and other activities sooner.