If you’ve been researching spinal fusion, it’s likely you’ve read and heard stories painting it in a not-so-positive light. On the other hand, you can also find people who claim the surgery reduced their pain and improved their quality of life. So how can you know what life after spinal fusion will be like for you?
You may never be able to predict exactly what your life will look like after spinal fusion, but you increase your chances of making the right decision when you do two things:
- Fully research the procedure and the long-term side effects of spinal fusion.
- Examine the available data around spinal fusion and its outcomes.
This article will get you started on both of the above.
Spinal Fusion: The Short- & Long-Term Effects
If you’ve done any research on spinal fusion, you already know how it works. In brief, a surgeon removes the disc material located at the affected level of your spine and all or part of the associated facet joints, packs the space with bone graft, and then inserts spacers, screws, and rods into the bones to temporarily hold everything in place. Eventually the bone graft fuses, the body heals, and what were once two separate vertebrae are now joined as one solid mass of bone. As a result, your spine has one less joint after surgery than it had before. The impact of having one less joint (or more if you have a multiple-level fusion) means your body won’t move in the same way after surgery. This local change of motion impacts your body in both the short-term and long-term.
What To Expect After Spinal Fusion Surgery: Short-Term Effects
In the short-term, you can expect that your movements may feel somewhat unnatural after spinal fusion surgery. Whereas people normally stand, sit, and bend without thinking about it, spinal fusion patients are almost always conscious of making those movements. Why? Because the loss of a joint means your spine loses its ability to naturally alter its curvature to accommodate your daily activities.
Everyone has a natural curvature to their spine that makes it an “S” shape, from the cervical spine (the neck) to the thoracic spine (the base of the neck to the abdomen) to the lumbar spine (the lower back). These curves change throughout the course of a day, as you sit, slump, lay on the couch, ride in a car, etc. When you’re standing upright, you have more of a curve in your lumbar spine than when you’re sitting. And when you’re sitting in a slumped position, you lose an even greater degree of lumbar curvature.
The removal of a joint during fusion creates an unnatural change in the curvature of your lower back. Surgeons try to compensate for the loss of a joint by fusing patients into a particular position—usually standing. That means the body is “locked” into that position, making it unnatural for sitting and slouching.
You may experience dramatic improvement in you leg pain symptoms after surgery, but there is a good chance you may suffer from residual back pain, either due to the new motion patterns of your spine, or even due to the fusion hardware itself.
If you’re faced with the prospect of spinal fusion surgery, find out about a new motion-preservation procedure that can address your pain and help you keep moving naturally.
The Long-Term Side Effects Of Spinal Fusion
Studies have shown that spinal fusion does have long-term side effects. Over time, many patients develop what’s known as adjacent segment degeneration. That’s because the absence of a vertebral segment (joint) changes the environment in which your spine operates.
By stiffening a segment where there once was a joint, you create abnormal mechanical loads for the spine segments above and below the fusion. Compare it to breaking an elbow: After wearing a cast for six weeks, you expect your elbow to be stiff when the cast comes off. At first you can hardly move it, and it may not be until weeks later that the joint stretches out and begins to move normally.
A similar situation happens with the joints above a fusion. Shortly after surgery, the muscles are contracted and stiff. Eventually they begin moving again, but for some people, the stiffness may only improve slightly. However, those joints adjacent to the fusion are now responsible for handling a greater mechanical load, which causes them to become hypermobile (to move excessively) over time. Because these nearby facet joints and discs are working harder and are under increased stress, they begin to weaken. Essentially, the movement in a fused spine never returns to a normal physiologic state.
What The Data Says
A 2017 presentation at the North American Spine Society annual meeting showed that patients who underwent disc replacement—a procedure that replaces the disc only, and leaves the facet joints intact—showed a degeneration rate of less than 4 percent, simply because they were able to maintain motion in the joints of their spine. Maintaining as little as five or six degrees of motion in your spine markedly lessens the magnitude of the mechanical forces, protecting your spine against adjacent segment degeneration.
Most patients develop symptoms of adjacent segment degeneration five years after fusion. Symptoms start out as exclusively back pain, but they eventually progress to leg pain due to destabilization of the segment followed by nerve compression. Some patients develop the condition sooner—as early as one year after fusion—while others take longer than five years.
How fast the condition develops also depends on how many fusions a patient has already had, and how many levels have been fused. The more levels that are fused the greater the mechanical forces will be on the adjacent levels, so degeneration will happen faster. And if it’s a second or third fusion, it is also likely to happen even sooner than five years.
A healthy spine is dependent on motion preservation. That makes sense if you think about how the other joints of your body—knees, hips, ankles, and shoulders—all have motion restored after surgery. The lumbar spine is the only place where fusion is acceptable.
The bottom line: When your spine loses its ability to naturally alter its curvature to accommodate your daily activities, it initiates an accelerated breakdown process that usually ends in further surgeries.
Data Surrounding Life After Spinal Fusion
Years of spinal fusion data is available, and new medical research continues to be published. It wouldn’t be possible to read every study in this area, but it’s important to seek out information in advance of surgery so you know what to expect.
The following are some important research conclusions to consider related to the long-term effects of spinal fusion:
- In relation to fusion vs. conservative treatments, current literature suggests that, in the long-term, fusion as a treatment for chronic low back pain does not result in an outcome clearly better than structured conservative treatment modes.
- In relation to fusion’s effectiveness, spinal surgery is between 50% and 70% effective, compared to 90+% positive outcomes for hip and knee surgeries, where joint replacement is common.
- Regarding reoperation rates, this study showed that one in five patients required reoperation within four years after surgery. Another showed that the two-year reoperation rate was 12.5%, and the four-year reoperation rate was 19.3%, with adjacent segment disease being the most common reason for reoperation.
- With regard to the relationship between fusion and adjacent segment disease, one long-term study on spinal fusion concluded that “fusion, particularly combined with laminectomy, does accelerate adjacent disc degeneration… [it] showed a 38% frequency of increased disc degeneration among fused patients compared with no increase in disc degeneration in conservatively treated patients.”
- Regarding the long-term effects of spinal fusion, another study showed a progressive worsening of patients’ conditions over the space of 15 years after spinal fusion surgery. Out of 73 patients, five years after surgery, seven patients required revision. By 10 years, 18 patients required revision, and by 15 years, 24 patients required revision.
- With regard to pain relief, 39% of patients who reportedly achieved overall success following surgery for single-level lumbar degenerative disc disease remained on narcotics 24 months later.
Spinal Fusion Surgery Is A Last Resort
Before you commit to terminal fusion, research all your options. Fusion should be a last resort salvage operation, only after you’ve tried a number of conservative treatments and investigated the alternatives.