The drastic increase in spinal fusions performed by surgeons in the United States has been attributed to several factors, including economic incentives for providers and relationships with device companies. However, there are several other, more subtle, factors that have contributed to the rise of spinal fusions that surgeons are keenly aware of, even if they aren't always mentioned in healthcare legislation and policy debates.
"There is an underlying economic incentive because surgeons are paid more for fusions than decompressions, but I don't think that's the main cause of this increase," says Hyun Bae, MD, Director of Education at Cedars Sinai Spine Center in Los Angeles. "I think the more important causes include the fact that we can perform spinal fusions easier. Developments in minimally invasive surgery, biologics and instrumentation have allowed us to obtain a fusion more reliably with less patient morbidity. All these factors combined have allowed us to perform spinal fusions on a greater population of patients."
Using data obtained from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample from 1998 to 2008, a group of researchers including Dr. Bae examined the numbers for an article published in the January 2012 issue of Spine: over that 10-year period, discharges for spinal fusion procedures increased 137 percent (from 174,223 to 413,171) between 1998 and 2008. The national bill for spinal fusions has also experienced a huge jump — from $4.3 billion in 1998 to $33.9 billion in 2008 — which is a 7.9-fold jump. Comparatively, knee and hip arthroplasty only experienced 5.1-fold and 3.5-fold increases over the same period.
"It's easy for people whose main focus is on cost of healthcare to look at particular procedures and identify the trends up or down, expensive or less expensive, and draw conclusions based simply on that type of user and demographic information," says Dennis Crandall, MD, founder and medical director of Sonoran Spine Center in Phoenix. "What it doesn't do, and where it isn't helpful, is understanding the group of patients with the disease process you are looking at in the first place."
The authors of "Spinal Fusions in the United States: Analysis of Trends From 1998 to 2008" sought to examine the numbers associated with spinal fusions over the past decade to draw a more holistic picture of spinal fusions in the United States. Here, several spine surgeons and specialists discuss which factors play the biggest role in this increase and how spinal fusions will likely trend in the future.
1. The increasing aging population demands spine care. One of the most heavily-cited reasons for the increase in spinal fusions is the influx of appropriately-indicated patients. Part of the natural aging process is experiencing spinal degeneration, and people are living longer today than ever. Coupled with the large baby boomer population and desire to remain active, surgeons are seeing more patients from the Medicare population who would benefit from spinal fusions.
"People are living longer and staying active longer," says Sheeraz Qureshi, MD, MBA, a spine surgeon at Mount Sinai Medical Center in New York City. "Degeneration of the bones and joints is a normal part of the aging process and this includes degenerative changes of the spine. Often these degenerative changes result in instability or stenosis and can benefit from surgical treatments including fusion."
In 1998, Medicare patients represented 21.3 percent of all spinal fusion discharges, which rose to 30.3 percent in 2008. While reimbursement for spinal fusions may be more than other treatments — such as decompressions or conservative care — Medicare reimbursement has steadily declined over the past decade to less than the cost of the procedure. By comparison, Medicaid patient representation only increased 0.5 percent over the same period.
"These baby boomers are just the first wave of individuals who are pretty healthy and active in their 60s and beyond," says Robert J. Banco, MD, associate clinical professor in the orthopedic surgery department at Tufts University School of Medicine in Boston and founding partner of Boston Spine Group, LLC. "These patients don't want to slow down and they don't want to live with pain. Our culture in this country is very into health and people don't want to stop being active and functional; they don't want to be impaired."
However, the increase in the aging population cannot completely explain the increase in spinal fusions; similar procedures — such as joint replacements and percutaneous transluminal coronary angioplasty — have increased at a much lower rate over the past decade. Overall, knee replacements hip replacements yielded 49.1 percent increase and knee replacements saw a 126.8 percent increase, compared to the 137 percent increase of spinal fusions.
"I trained in England where they have a national health service and even though the medical care is very good and the physicians are excellent, many patients suffer in pain for a long time before they can have surgical treatment," says Robert Watkins, Jr., MD, co-director of the Marina Spine Center at Marina Del Rey (Calif.) Hospital. "I think in America, we expect to be healthy and pain free, and if anybody has pain or limitations in their life, they want to treat it as soon as possible. Americans desire to be as good as they can be immediately; sometimes surgery is done aggressively because of the patient's and physician's desire to be well immediately."
2. Comorbidities aren't as prohibitive. Patients with comorbidities were once considered non-candidates for surgery because of their condition. However, but better anesthetic and perioperative support has allowed surgeons to perform spinal fusions for patients who weren't considered good candidates for surgery 10 years ago.
"The technology has improved dramatically so you can do these procedures in elderly patients who have comorbidities," says Neel Anand, MD, director of spine trauma and minimally invasive spine surgery at Cedars-Sinai Spine Center in Los Angeles. "We are able to do complex spinal fusions minimally invasively so an older patient can tolerate it. Ten years ago, these patients would have had too many comorbidities for surgery."
Before the advent of modern surgical technique, it was too risky for patients with heart issues or at a certain advanced age to undergo surgery. Now medical professionals are able to manage those conditions, along with many others, and perform successful surgery. This means spinal fusions have become a viable option for a significant number of new patients who meet the appropriate indications.
"Our overall medical care in this country has improved so much that people in their 70s, 80s and 90s can undergo spinal fusions more safely now, whereas 10 to 20 years ago surgeons may have said they were too old to undergo surgery," says Dr. Watkins. "People are in good status so they can tolerate spinal fusions."
Published data also supports this trend. According to the article, the average age for spinal fusions in 1998 was 48.8 years old and rose to 54.3 years old by 2008. Approximately 26.5 percent of patients were over the age of 65 by 2008, well over the 18.5 percent of patients who were older than 65 in 1998.
"Additionally, surgical times are shorter with minimally invasive procedures," says Dr. Watkins. "Some of these multi-level fusions, for instance, may have taken eight to 10 hours in the past and someone over the age of 70 probably wouldn't be recommended for the procedure. These days the surgery can be done safely in four hours and people have good medical care, so there's a relatively low risk of undergoing surgery."
3. Advancement in surgical technology. Beyond just expanding options to more patients with comorbidities, the advancement of surgical technology has made the procedure easier for all patients to withstand. Surgeons across the country are now training in less invasive ways to approach the spine.
"The improvements in the surgical technology have made performing spinal fusions more effective, therefore they are done more often," says Dr. Watkins. "Computer navigation allows us to put instrumentation such as pedicle screws into the spine minimally invasively with three-dimensional visualization, which makes the procedure safer and faster. In some difficult cases 20 years ago surgeons wouldn't recommend surgery for patients because it was too dangerous, but now it can be done more safely because of computer navigation."
Through these new techniques, surgeons can perform spinal fusions through a smaller incision without muscle disruption. As a result, the procedure time is shorter, blood loss is less and recovery time is quicker.
"We are able to treat people with more medical conditions and allow healthy patients to undergo more complex surgery safely because of our perioperative team," says Steven Lee, MD, a spine surgeon with Muir Orthopaedic Specialists in Walnut Creek, Calif. "People who have multiple medical problems are now able to withstand surgery because the medical care around surgery has improved."
Technology is exploding now and driving some of the increase, but it may slow over the next several years. "Medical advances happen much more slowly than advances in information technology," says Stephen T. Onesti, MD, director of neurosurgery at South Nassau Communities Hospital in Oceanside, N.Y. "The body is very complex and there are a lot of regulatory and quality issues that must be addressed with each new innovation."
4. Quicker recovery times. When making the decision about whether to undergo surgery or continue managing the condition, many patients in the past were weary of the long hospital stays and recovery times, so they opted out of surgery.
"As we continue to do surgery less invasively, such as direct lateral fusions, we can give patients the same positive results with a quicker recovery time," says Dr. Qureshi. "The quicker recovery has been a factor in the increasing number of spinal fusions because we can get patients better faster."
Over the 10 year period in the study, length of stay at the hospital decreased from 4.4 days to 3.7 days for spinal fusions. For primary cervical fusion, the length of stay was reduced from three days to 2.7 days; for primary thoracic fusion, the length of stay was reduced from nine days to 8.5 days; and primary lumbar fusion length of stay was reduced from 4.9 days to 3.9 days.
"In the spine market, there is a lot we don't know and we are still discovering," says Dr. Crandall. "There are several ways to achieve good results and surgeons have a lot of options to decide with patients the best treatment pathway. Over time, we will see fewer technologies embraced long term because they are supported by the data."
Spine spinal fusions are even being performed in outpatient an ambulatory surgery center, which means patients return home less than 24-hours after the procedure. "The patients are able to undergo early movement and ambulation, which leads to better functional results early on in the course of recovery," says Steven Lee, MD, a spine surgeon with Muir Orthopaedic Specialists in Walnut Creek, Calif. "As a result, patients are more willing to accept fusions as a reasonable solution for them."
Now that spinal fusions are less extensive and allow people to return to work and play more quickly, additional appropriately indicated patients are choosing surgery instead of living with pain after failed non-operative therapies.
"In my experience, in a vast majority of patient who are appropriately selected, spinal fusions can have a clear advantage over conservative treatment," says Dr. Onesti. "There have been some nice studies done as well to show lumbar fusion is effective in appropriate patients."
5. Stalled innovation in non-fusion procedures. While the advancement in spinal fusion has been rapid, innovation in the non-fusion technology has been stalled by the regulatory process and insurance companies. Even though studies are available showing non-fusion technology, such as disc replacement, can have good outcomes and benefits in some patients, many insurance companies won't pay for the technology and the FDA approval process is onerous on device companies.
"Non-fusion procedures never really got going for a number of reasons," says Dr. Anand. "The FDA approval process is expensive and time consuming; then, even after the device receives approval, insurance companies won't cover it. We have two discs right now that were approved after extensive studies, but they are denied by payors. If nobody is paying and authorizing for the technology, it won't be around."
Non-fusion and motion sparing technology is a field of increasing interest among surgeons willing to innovate, but application of those technologies is difficult.
"I was involved in a study with a facet-type device that we had to abandon because of funding," says Jaideep Chunduri, MD, a spine surgeon with Beacon Orthopaedics & Sports Medicine in Cincinnati. "It costs so much money to conduct these studies. You will see fewer novel ideas developed in the future because it is so expensive to conduct research."
However, if innovation in the field of disc arthroplasty continues and insurance companies begin covering it, spinal fusions may decrease as more surgeons and patients opt for non-fusion procedures.
"Looking forward, as we research the effects of spinal fusion and begin to investigate other motion preserving technology and less invasive technology, we are understanding better that there are certain disease processes and techniques that can be used for patients whereas in the past the only option was spinal fusion," says Dr. Crandall. "Going forward, we will see a trend of somewhat of a decrease in the total number of spinal fusions done, in a real sense, as surgeons shift to more motion-preserving techniques and technology."
Additional research areas, such as biologics, may also become a player in the spinal field down the road. "Some fusions might be replaced with motion sparing technology or biologic discs — that's the next step," says Michael J. Halperin, MD, a spine surgeon with Norwich Orthopedic Group in North Franklin, Conn. "One day we may be able to utilize stem cells to grow a new disc or some other tissue which could have a similar functional role."
6. Fusion is more easily achieved. Along with advancement in other surgical technology, fusion material has changed to allow for more dependable fusion rates. In 1998, most spine surgeons were using bone harvested from the iliac crest to enhance the fusion; now, surgeons are able to use synthetic biologic agents such as bone morphogenic protein products to promote fusion.
"In 1998, probably around 70 to 80 percent of surgeons were using iliac bone crest for fusion; now it's probably less than 10 percent," says Dr. Bae. "This development has changed our attitude toward fusion and bone grafting. I don't think the morbidity of achieving a fusion with biologics and instrumentation is the same as it was in 1998."
By using the appropriate amount of synthetic fusion material, some spine surgeons are able to achieve fusion nearly 100 percent of the time, including with complex cases where a successful fusion would have been unlikely otherwise.
"We now have bone morphogenic protein that gives us the ability to approach a 100 percent fusion rate without going to the patient's pelvis," says Dr. Halperin. "This has made it easier for fusions to become more prevalent. People are more willing to undergo surgery because the old horror stories of having to undergo multiple operations before the fusions are achieved aren't as common any longer."
7. The procedure is safer than in the past. In-hospital mortality rates have also decreased for spinal fusion from 0.28 percent in 1998 to 0.25 percent in 2008. Primary lumbar fusion in-hospital mortality rates decreased significantly, from 0.15 percent in 1998 to 0.12 percent in 2008. These rates can be attributed to the advancement in technology and procedures, but risks are still a huge factor when surgeons and patients are deciding whether spinal fusion is a good option for them.
"Fusions are often associated with a higher degree of morbidity, especially when surgeons harvest bone from the iliac crest, which is one reason why surgeons in the past were hesitant to perform the procedure," says Dr. Bae. "Since we've introduced biologics to achieve fusion, there has been a change in attitude about spinal fusions among surgeons because there is less morbidity associated with the procedure now."
The refinement of the spinal fusion technique also eliminated concerns about morbidity and opened the door for more patients to receive the procedure. "When someone develops mechanical instability, and instability is a natural part of the aging process, fusion is effective most of the time," says Dr. Watkins. "Fusions are here to stay; as technology advances, surgeries will be done less invasively and more safely."
Over the past 10 years, small-bed-size hospitals performed 9 percent of all spinal fusions in 1998, which grew to 12 percent in 2008. By contrast, medium-bed-sized hospitals accounted for 26.8 percent of all fusion discharges in 1998 and 21.2 percent in 2008. There was a slight increase in the percentage of procedures performed in large-bed-size hospitals.
"If you follow strict outlines on stability, the data we have proves fusion is a good procedure," says Dr. Chunduri. "In the 1990s, everyone had cage rage; now we are in an era of fusion rage, but if patients have the indications to perform the procedure it can be very helpful. I think the current rates of spinal fusion will remain the same for a while."
8. More spine surgeons are becoming fellowship trained. In some regions of the country, spinal fusions may have increased simply because there were more specialty-trained spine surgeons available to perform them. "I did my spine surgery fellowship from 1991 to 1992," says Dr. Halperin. "Back then, in this country, spinal surgery was predominately performed by general orthopedic surgeons and neurosurgeons. Although they both had some training in spine surgery, they tended to be generalist who did a little bit of everything. Today we have fellowship-trained spine surgeons who have a better understanding of the pathophysiology associated with spinal disorders. These surgeons have the skills and training to better accomplish what previously was considered to be difficult or complex."
This doesn't mean that surgeons are performing unnecessary surgery for a well-covered population; it means appropriately indicated patients were previously left untreated because surgeons weren't accessible.
"The number of laminectomies performed decreased while the number of spinal fusions increased," says Dr. Bae. "There were a lot of non-spine specific surgeons who were doing laminectomies, but the fellowship training and dedication to spine surgery allows surgeons to perform more complex spinal fusions. We can see the same trend occurring with percutaneous angioplasty as well."
Neurosurgeons are also becoming more confident in performing spinal fusion — a procedure they left to orthopedic surgeons in the past. "With the passage of time, more orthopedic and spine surgeons have emerged with the ability to practice high quality spine surgery and there has been a dramatic increase in neurosurgeons comfortable and very effective at solving spine-related disease with techniques such as fusion," says Dr. Crandall. "We have a significant growth in people who are qualified, comfortable and capable of doing spine work."
Along with the increasing number of fellowship-trained physicians, spine surgeons are also more likely to become members of a single-specialty group than they were in the past, focusing on spine care. Even in hospitals, spine-focused units are popping up that pair patients with highly trained specialists in areas where that expertise may not have existed in the past.
"Single specialty comprehensive spine groups exist all over the country," says Dr. Banco. "These groups deliver care from the entire spectrum of disorders, from the trivial on one end to the spinal reconstruction on the other. One of the reasons spinal fusions are increasing is because we have these single specialty groups where surgeons truly understand how to treat patients from the beginning of their spinal disorder all the way through until they might require reconstructive procedures."
9. DDD diagnosis is increasing. One of the most interesting statistics coming from the report was the diagnosis for spinal fusion. In 1998, degenerative disc disease was the third most common diagnosis prior to spinal fusion, representing only 9.1 percent of the cases. However, by 2008, DDD was the most common diagnosis, representing nearly 14 percent of all cases.
"There is a big spectrum of what falls under the diagnosis degenerative disc disease," says Dr. Anand. "At one end of the spectrum, there are patients who are just starting to develop degeneration — black disc — but the disc height is maintained and there isn't any instability; on the other hand, there are patients who have a collapse of the disc space and instability, which go along with aggressive degeneration. The latter group may benefit from a spinal fusion, but unfortunately a lot of insurance companies lump all DDD into one basket."
Some insurance companies, most notably Blue Cross Blue Shield of North Carolina, are writing guidelines that say they won't cover spinal fusions for patients with DDD as the singular diagnosis. "The real issue comes in when we don't have the appropriate indications fur surgery based on the insurance company's guidelines," says Dr. Qureshi. "Spinal fusions for DDD can be a very gratifying operation in the right patient."
Surgeons across the country are feeling push back from payors regarding spinal fusion coverage, which could present access to care issues. "Spinal fusions are a great operation if properly done with the proper indication," says Dr. Anand. "Medicine will always be an art; not a science. That's where experience and technology come in."
One of the reasons why DDD has become a more prevalent diagnosis is because there are more people who are entering into the demographic most at-risk for spinal degeneration: the elderly population. "You are seeing more severe spinal stenosis and DDD," says Dr. Chunduri. "You are seeing more patients who have the conditions that necessitate spinal fusion. Even though the insurance companies are strict with who can have a spinal fusion, we are still seeing this increase."
If the strict guidelines from insurance companies persist, we may see a decrease in spinal fusions because patients won't have access to those procedures unless they pay out-of-pocket, which is expensive. "We don't know what type of restrictions will be placed on us by government and insurance companies," says Dr. Onesti. "Surgery will be scrutinized and practitioners must show good quality outcomes for cost-effective care."
10. More research is available on spinal fusion indications. There are several factors that impact individual patients' response to treatments and procedures, including their overall healthcare, demographics and history. Research into these different areas has allowed surgeons to become more comfortable about reliably predicting success in their patients.
"As we have understood disease processes better and researched outcomes on what types of treatments make people feel better, spinal fusions continue to be durable in its ability to improve pain and function in people with certain types of diseases," says Dr. Crandall.
Payors are now paying sharp attention to each study released about the effectiveness of spinal procedures and applying strong data to evidence-based guidelines for recommendations and coverage.
"There has been a lot of emphasis on evidence-based medicine and outcomes driven by procedures," says Dr. Banco. "There are some groups, like The Boston Spine Group, that have very large databases and follow patients long term to gather information on which surgeries work, which don't and where there are high complication rates. These databases have given us a map that allows us to apply the technology to patients more effectively."
By examining the data, surgeons can be more confident about which patients are likely to benefit from spinal fusions and which patients will have better outcomes with other treatments. "It's important that we don't over-perform the procedure without the appropriate indications because then we will see the results diminish," says Dr. Qureshi. "We don't want to get to the point where we are fusing three or four levels in every patient's back who has arthritis."
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