Spinal Fusion: When is it Necessary and Can it be Achieved with Minimally Invasive Spine Surgery?

By February 5, 2015 Spine Relief No Comments



In a recent post, we discussed Dallas Cowboys quarterback Tony Romo’s spine conditions and his herniated disc treatment with minimally invasive spine surgery. In Romo’s case, spinal fusion was not necessary in his treatment for a herniated disc. By comparison, the minimally invasive spine surgery Denver Broncos QB Peyton Manning needed to heal his neck pain and arm weakness was a pinched nerve treatment called anterior cervical discectomy that did require fusion.

Why did Manning need a fusion if Romo didn’t? In this post, we will discuss what spinal fusion actually means and when it is necessary. Importantly, both quarterbacks made excellent recoveries after receiving the minimally invasive spine surgery they needed. In fact, both were selected for the 2015 Pro Bowl! The same spine surgery procedures are routinely performed to achieve back pain relief at Minimally Invasive Surgical Institute by our fellowship-trained spine specialists.

What is spinal fusion?

Simply put, spinal fusion refers to connecting or “fusing” two adjacent bones in your back. To really understand spinal fusion we have to discuss a little anatomy, including the basic bones and joints that make up your spine.

Your spine is made up of a series of 33 bones (called vertebrae) that extend from your skull all the way down to your hips, forming the spinal canal (a protective tube of bone that your spinal cord runs through). There are 3 major joints that connect adjacent vertebrae at each spine level: a pair of 2 facet joints and 1 intervertebral disc (which is a special type of joint).

Intervertebral discs are in the front of your spinal canal and act as shock absorbers for the wear and tear of everyday life. Facet joints are at the back of your spinal canal and are key to the flexibility in your spine, allowing you to bend forward and lean back. They also provide structural stability to the spine, preventing one vertebrae from sliding too far away from the other, which could narrow your spinal canal and injure your spinal cord.


How is spinal fusion achieved?

In spinal fusion procedures, the soft and mobile joints between vertebrae are replaced by strong bone that enhances stability, providing back pain relief. In most cases, parts of the spinal joints are removed to make space for bone to grow and connect the two adjacent vertebrae. Often times, removing part of the intervertebral disc and/or facets is also very therapeutic, because when these joints degenerate they can put pressure on the spinal cord and nerve. Removing the intervertebral disc in the lower back is called a lumbar discectomy surgery, and removing a disc in the neck is called a cervical discectomy.

Following the removal of joint material from the facets and discs, this space is filled with biologic substances that promote bone growth across the joint space –Fusion! Since you have 33 vertebrae, losing movement at a few levels due to fusion generally has a relatively small impact on the overall flexibility of the spine.


Why does spinal fusion require implants such as rods and screws?

In order for bone growth to occur across adjacent vertebrae, that segment of spine must be kept stable. If the spine were to move too much at the site where bone growth is supposed to take place, fusion would not occur. Implants such as screws and rods are used to hold vertebrae at that spinal level in place while fusion develops. A piece of scaffolding (called an inter-body graft) is often also used to maintain the spacing between vertebrae and aid in fusion. Once fusion occurs, these implants serve no purpose, but they are generally left in place because they do not cause discomfort.


When is spinal fusion necessary?

The main indications for spinal fusion are to enhance spinal stability and/or improve spinal balance. By improving spinal stability and balance, fusion procedures can reduce pain and improve neurologic function. Spinal balance is critical to the pain free function of our spine and essential to our ability to stand upright without expending too much energy. In some cases, individuals are born with their spine curves out of balance (pediatric scoliosis). In others, spinal imbalance is the result of arthritis and progressive degeneration of the spine. In both cases, fusion procedures can be used to restore spinal balance.

Fusion is more frequently used to correct spinal instability, which simply refers to motion of spine segments that is greater than normal. The physical stress of everyday life often leads to degeneration of the joints in the spine, which can cause spinal instability. The increased movement of degenerated unstable joints leads to more inflammation, greater degeneration and further instability – it is a viscous cycle. Joints in the spine are very sensitive and the whole process is incredibly painful! The goal of fusion procedures is to replace these painful unstable joints with solid bone that provides stability and reduces pain.


What are some common spine fusion procedures? 

Spine surgery continues to evolve at an exciting pace, with experts using new technology and novel techniques to treat spine conditions and provide back pain relief. The most common fusion procedure used to treat spine conditions affecting the neck and arms is called an anterior cervical discectomy with fusion (ACDF). Spine conditions affecting the lower back and legs can be treated with lumbar fusion procedures, including transforaminal lumbar interbody fusion (TLIF), and direct lateral interbody fusion (DLIF). If you are considering a spinal fusion, you should discuss which technique your surgeon plans to use and why.


Are there minimally invasive options? And if so, what are the advantages?

Yes! All of these fusion procedures can be achieved through minimally invasive spine surgery. Minimally invasive techniques minimize bleeding, muscle cutting and trauma to the surrounding soft tissue. This reduces post-operative pain and accelerates recovery compared to traditional surgery options.


What type of doctor is qualified to perform a spinal fusion?

Technically, any orthopedic surgeon or neurosurgeon is licensed to perform a spinal fusion.  But given the technical and constantly evolving nature of complex fusion surgeries, doctors who have special fellowship training in spine surgery are the most qualified to perform the procedure. If you are considering a cervical or lumbar fusion and are interested in learning more about the benefits of minimally invasive spine surgery, make an appointment with one of our fellowship-trained spine surgery specialists.

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