Not everybody with low back pain will require surgery. But if your condition is one that requires surgery, rest assured that spinal fusion has a long history as a treatment option.

A spinal fusion is the permanent joining of two or more vertebrae so that there is no movement between them. Over time they heal into a single, solid bone. The procedure involves roughening the bone between two adjacent vertebrae and then placing bone graft between them. In some cases, disc material may be replaced with donated bone, or in the case of degenerative disc disease with or without Grade 1 spondylolisthesis, plastic or metal spacers may be used instead. Rods and screws are then placed to create an "internal cast" that support the vertebrae, holding it together until the fusion, or bony regrowth, can occur.
Spine surgery involves creating a single incision and stripping the muscles from the spine. In comparison to a minimally invasive technique, the “open” method offers key benefits that include:
• Increased access to the spine to remove the damaged bone or intervertebral discs with less likelihood of leaving compressive elements behind
• Greater visibility to the surgeon in order to place the rods, screws, and bone graft materials needed to stabilize the spinal bones, and hence create less risk of damage to nerves or surrounding structures

When surgeons replace disc material with either bone, plastic, or metal spacers, they may approach the disc space in different ways:
• Anterior lumbar interbody fusion (ALIF) – An incision is made in the abdomen
• Posterior lumbar interbody fusion (PLIF) – An incision is made in the back
• Transforaminal lumbar interbody fusion (TLIF) – An incision is made in the back next to the spine to access the vertebra at an angle
• Direct lateral interbody fusion (DLIF) – An incision is made on the side of the abdomen

All these procedures can also be done using a minimally invasive technique, and all involve joining different parts of two or more vertebrae together. Your surgeon will decide on the best approach after considering various factors, including the spinal condition to be treated, its location in the spinal column, and your overall health.

Spinal fusion is surgery to permanently join together two or more bones in the spine so there is no movement between them. These bones are called vertebrae.

You will be asleep and feel no pain (general anesthesia).

The doctor will make a surgical cut (incision) to view the spine. Other surgery, such as a diskectomy, laminectomy, or a foraminotomy, is almost always done first. Spinal fusion may be done:
• On your back or neck over the spine. You will be lying face down. Muscles and tissue will be separated to expose the spine.
• On your side, if you are having surgery on your lower back. The surgeon will use tools called retractors to gently separate, hold the soft tissues and blood vessels apart, and have room to work.
• With a cut on the front of the neck, toward the side.
The surgeon will use a graft (such as bone) to hold (or fuse) the bones together permanently. There are several ways of fusing vertebrae together:
• Strips of bone graft material may be placed over the back part of the spine.
• Bone graft material may be placed between the vertebrae.
• Special cages may be placed between the vertebrae. These cages are packed with bone graft material.

The surgeon may get the bone graft from different places:
• From another part of your body (usually around your pelvic bone). This is called an autograft. Your surgeon will make a small cut over your hip and remove some bone from the back of the rim of the pelvis.
• From a bone bank. This is called an allograft.
• A synthetic bone substitute can also be used.

The vertebrae may also fixed together with rods, screws, plates, or cages. They are used to keep the vertebrae from moving until the bone grafts are fully healed. Surgery can take 3 to 4 hours.

Spinal fusion is most often done along with other surgical procedures of the spine. It may be done:

• With other surgical procedures for spinal stenosis, such as foraminotomy or laminectomy
• After diskectomy in the neck
Spinal fusion may be done if you have:
• Injury or fractures to the bones in the spine
• Weak or unstable spine caused by infections or tumors
• Spondylolisthesis, a condition in which one vertebrae slips forward on top of another
• Abnormal curvatures, such as those from scoliosis or kyphosis
• Arthritis in the spine, such as spinal stenosis.

You and your doctor can decide when you need to have surgery.