Overview of Spinal Fusion Surgery

DISEASES OF THE SPINE such as spinal stenosis, degenerative disc disease, scoliosis, a spinal tumor, spondylolisthesis or traumatic spine injury may require surgical intervention. Typically, when the resulting neck or back pain becomes so severe patients will seek treatment. Often, the pain symptoms can be treated with conservative care such as physical therapy, over the counter medications or steroid injections which are the preferred methods to prevent or delay the need for surgery. If these treatments do not resolve the discomfort within a few weeks, or the pathology is already too severe,  depending on the diagnosis and long-term goals of the patient, one type of surgical intervention is a spinal fusion. A spinal fusion entails surgical procedures that rebuild damaged unstable vertebral bone and spine joints. The aim of this operation is to structurally strengthen and stabilize the unhealthy parts of the spine to the adjacent health segments of the spine. Spinal fusions are extremely effective when performed by experienced, skilled surgeons such as those at Centers for Neurosurgery, Spine, & Orthopedics. The CNSO dedicated team has years of successfully diagnosing, conservatively managing, and if necessary, performing the correct spinal surgery for our patients.

When is Spinal Fusion Necessary?

A spinal fusion may be necessary if the vertebral bones are significantly misaligned with one another or are severely deformed or damaged. One or a combination of these defects can occur at one or more levels of the spine. In every case, the patient is chronically uncomfortable or is losing the ability to function because nerves or the spinal cord itself is being pinched. Depending on the medical conditions being addressed, a spinal fusion will also resolve problematic pinched nerves and pressure on the spinal cord. Both the  neural decompression and spine fusion surgery would be performed in one surgical session. Below is the description of each category of surgery:

1. Neural Decompression Surgery – Used to remove and free a pinched nerve or spinal cord. The spinal cord and nerves normally travel in tunnels within the bones and joints that make up the spinal column. Many disease states, usually arthritis and trauma, can narrow these tunnels, causing the neural structures to become compressed. This compression causes pain, tingling sensations, weakness and a loss of function which can escalate to dysfunction or even paralysis. When this weakness or loss of function occurs, surgical decompression of the neural elements by a neurosurgeon or an orthopedic spine surgeon is required. Depending on which part of the spine is problematic, such as a slipped disc or arthritic bone spur growth, surgical procedures called discectomy, facetectomy, foraminotomy, or laminectomy may be used. These surgeries remove compressive bone or disc pathology off neural elements allowing the patient to be pain free again.
2. Spinal Fusion Surgery – When joints or vertebral bones of the spine become severely arthritic, damaged by trauma, or brittle because of invasive malignant bone tumor, the spinal column may become unstable and impinge on the surrounding nerves and spinal cord itself. Or if a spinal cord tumor, such as an astrocytoma or meningioma of the spine develops, it must be removed. In order to access the tumor, however, the surrounding bone must be removed. Whether the spine pathologic condition is within the bone or within the spinal cord, it may be necessary to surgically restructure and stabilize the surrounding vertebral bone after the diseased area is removed.

 What Happens in Spine Fusion Surgery?

The goal of fusion surgery is to restore the normal anatomical alignment of the vertebral bones and permanently secure the alignment in the most functional biomechanical position. This allows the patient to move with little to no discomfort.

The spine fusion procedure starts with a small incision, directly above the area in need of repair. Next, the damaged spine vertebra or intervertebral disc that has become problematic and painful is most likely trimmed back or if necessary, is removed. If the goal is to remove a spinal cord tumor, the least amount of vertebral bone is removed in order to clearly access the tumor and successfully remove all of it.

Once this has been accomplished, the bones of the spine are restored to their normal anatomical alignment. Then bone or bone-like filler, called a bone graft, and perhaps a synthetic device will be placed in the necessary spinal column areas to maintain the original or correct spine height.

This prosthetic, usually made of carbon fiber, plastic, or 3-D printed titanium, maintains the restored distance and alignment of the bones, creating a solid fusion across the joint space.

Lastly, to assure that the bones hold their position and new bone growth takes place, the addition of stabilization hardware such as pedicle screws or a titanium plate will be applied.

Examples of Common Spinal Fusion Surgery

• Anterior Cervical Discectomy and Fusion (ACDF): The cervical neck disc that is herniated or torn is approached from the front or anterior side of the patient. The problematic portion of the vertebral bone and cervical disc is removed. A construct is then placed to leave the native spinal column securely in place and enabling the patient to comfortably resume all physical activities for the rest of their life.
• Anterior Lumbar Interbody Fusion (ALIF): The operation is performed at the level of the lower back by anteriorly accessing the lumbar spine. The benefit of an ALIF is less time under anesthesia allowing for a quicker recovery compared to the older technique of resolving a lumbar spine condition by a posterior lumbar spine surgery followed by an anterior lumbar surgery both performed on the same day. With an ALIF approach, patients also have significantly less postoperative discomfort compared to an Anterior/Posterior open staged surgery.
• Transforaminal Lumbar Interbody Fusion (TLIF): Departing on the part of the lower back that is causing the patient’s pain and discomfort, the transforaminal approach may allow the least invasive angle to correct the spine pathology while using a minimally invasive approach. For the TLIF, once the patient is anesthetized the patient will be placed, face down, in the prone position. The surgical incision will be placed on the posterior lower back side of the patient, 45-50 mm lateral to the midline of the spine. This access point angle will allow the neurosurgeon or orthopedic spine surgeon to visualize both the lateral and anterior side of the spine where the correction of the spine pathology and the stabilization of the spine needs to occur. This technique can be used for a number of spine conditions including spondylolisthesis.
• Robotic surgery: With the use of robotics and spine navigation systems, incisions can be minimized and OR time further reduced.  The use of robotics is especially beneficial if the patient has a multilevel spine condition, spinal deformity, or is in need of spine revision  CNSO neurosurgeons and orthopedic spine surgeons use robotics for these complex cases in New Jersey hospitals.  If a multi-side approach is necessary, robotics help minimize anesthesia time by limiting the need to reposition the patient during the operation which is required for more traditional surgical access positions.