What is the impact of the implant revolution? Comprehending the reach of medical devices in our world requires a full accounting of the costs, a consideration of the number of operations, and a tabulation of the total number of devices implanted every year.
Turn on a televised political debate and you will hear about the “massively inefficient” US medical system, so described because of its “runaway expenses.” This focus on costs is critical, especially because Medicare spending is part of the enormous direct, or mandatory, spending that is considered an entitlement for US citizens. The US government spent $692 billion of our dollars on Medicare in 2016, which was a 9 percent increase over 2015.1
Importantly, “inefficient” can be different than “costly.” Do we decry the costs associated with building (and rebuilding) municipal airports because modern jet airplanes need longer runways? Do we complain about the new costs of visually stunning LED flat panel televisions in relation to our grandparents’ radios? Of course, we all complain about the expenditures in our public and private lives, but we gladly pay for home Wi-Fi, smartphones, and drive-through coffee shops—modern conveniences we can’t imagine living without.
The real question is, how much are we willing to pay for healthcare? As was outlined in chapter 12, no member of Congress could have possibly guessed what was brewing in the minds of scientists and physicians in 1965. In 1967, the first full year of Medicare and Medicaid implementation, total federal spending on Health Services and supplies was less than $10 billion, with $5.5 billion allocated on hospital care2 ($38.4 billion in 2015 dollars).3 Who could have dreamed that annual federal spending on health care could increase 1,700 percent in half a century? Outcomes in the treatment of cancer, heart disease, and arthritis have dramatically improved in the last fifty years, but the question remains, how much are we willing to pay?
Some healthcare critics have cited a doomsday event of sorts wherein one day we might spend more money on healthcare than our mortgages. Even acknowledging the tragedy of uninsured Americans and poor healthcare outcomes among disadvantaged families, shouldn’t we prioritize the health of our bodies above the status of our houses? Hopefully, we can avoid that mathematical reality, but a bit of the sting of sticker shock is placated by an appreciation of how very far we have come in the last seventy-five years.
A tabulation of implantable medical devices will now be offered. The simplest way of accomplishing this will be by specialty, but because there is no national registry this is a daunting calculation. The methodology is based upon a combination of US federal government information and industry reports. Both require the purchasing of reports and the consultation of experts.
A review of implants based upon their longevity (temporary versus permanent) and structural makeup was proposed (organic, biological, plastic, metal, and electronic). Every implant that exists in a human can be described as some combination of those descriptors.
Another way of categorizing implants is based upon their function. Implants are used for: repair, reconstruction, substitution, stabilization, restoration, augmentation, and electrical stimulation. This classification is mine, and is presented, not as a factual representation but as a conceptual approach.
Repair implies the realignment of our own tissues, like sewing lacerated skin edges together or attaching tendon edges to a bone, like rotator cuff repair. Repair almost always entails the use of suture, and more often than not, permanent suture that is intended to stay forever. Open-heart surgery and repair of the mitral valve (between the left atrium and left ventricle) involves a great deal of permanent sutures and, oftentimes, a permanent reinforcing mesh ring for annuloplasty.
Reconstruction involves implanting a new tissue into a specific area with the expectation that the body will (miraculously) respond by: 1) not rejecting the tissue, 2) microscopically responding by accepting and incorporating the tissues to nearby structures, and 3) functionally adapting the tissues to adopt the role of previous tissues. The most common reconstruction operation every year in the world is anterior cruciate ligament (ACL) reconstruction, in which tendon from a patient (or cadaver) is implanted in a patient’s knee, and after healing, functions as a stabilizing and critical knee ligament.
Substitution surgery involves complete replacement of a worn-out or diseased body part with an implant that is meant to restore function. Examples include joint replacement, wherein the arthritic bony surfaces, with their worn-out cartilage, are resurfaced with metal or ceramic parts, or heart valve replacement surgery, in which diseased or misshapen valves are replaced with animal (pig or cow) or metal implants. Substitution surgery can not only restore previously lost function, it can prolong life and dramatically improve a person’s existence.
Stabilization surgery involves the implantation of devices that bolster the body during a restorative healing process. Stabilization differs from repair in that an additional structure, like a metal plate and screws, is configured adjacent to a biological zone for healing. Severe displaced fractures are internally stabilized with trauma hardware, which allows the bone ends to slowly knit together. Similarly, spinal fusion is achieved by linking vertebrae together with large screws and rods, attaining a fusion of neighboring structures. Under the right conditions, this type of fusion is advantageous, but only occurs when the stabilization is so secure that the cells can accomplish solid healing across the chasm.
Restoration surgery reinstates function when the body cannot achieve it on its own. When a heart has lost its own rhythmic pacing ability due to diseased electrical conducting nerves, there is no medicine or nonsurgical treatment that can restore normalcy. Implantation of a pacemaker restores regular pacing of the heart—a profound and modern miracle. Another, more recent marvel is deep-brain stimulation, in which precisely placed electrical leads are positioned in tiny areas of the brain to affect a mood, an inhibition, or excitation. Tremors or seizures are decreased (even abolished); memory is enhanced, depression is lifted, and perhaps, Alzheimer’s is held at bay.
Augmentation surgery and other types of plastic and aesthetic surgery do not enhance function, but instead alter appearances with permanent implants. In the case of augmentation breast surgery following mastectomy, the line is blurred between augmentation and restoration.
In fact, the lines are often blurred among categories. For instance, a cochlear implant is used to restore hearing among the deaf, but is this restoration or substitution? When a cardiac stent is precisely snaked into a coronary artery, is this repair or restoration? Whatever the case, implants powerfully facilitate healing at the hands of physicians and surgeons. As Francis Bacon dreamed four hundred years ago, “Let us hope … there may spring helps to man, and a line and race of inventions that may in some degree subdue and overcome the necessities and miseries of humanity.” Here, then, is a computation of the lines of invention.
Orthopedic surgeons facilitate the implantation of more devices than any other specialty. Joint arthroplasty of shoulders, elbows, wrists, fingers, hips, knees, ankles, and toes, combined with spinal fusion, fracture management, and tendon and ligament repair result in millions of operations every year in America. Prior to Smith-Petersen’s cup arthroplasty in Boston in 1938, almost no implantation of metal occurred in America, and for another decade, a slow uptick in the rate of implantation occurred. During the 1950s, orthopedic surgeons in America, Europe, and Japan began pioneering joint arthroplasty, and by the 1960s the revolution was in full bloom.
As discussed elsewhere in this book, there is no US joint registry, so appraisals about joint replacements are based upon commercial and governmental estimates. The most reliable estimates are contained in the National Inpatient Sample (NIS), the “largest all-payer inpatient care database in the United States, containing data on more than seven million hospital stays.”4 NIS is the largest database compiled by the Healthcare Cost and Utilization Project (HCUP), and is sponsored by the Agency for Healthcare Research and Quality (AHRQ), itself a part of the US Department of Health and Human Services (HHS), with a tiny budget compared to other divisions like the NIH, CDC, CMS, and FDA. Information in the NIS captures about 20 perent of all hospital discharges, so extrapolation of the data must be performed to come up with national estimates.
The first FDA-approved total hip replacement in the United States was performed by Dr. Mark Coventry at the Mayo Clinic on March 10, 1969. John Charnley had been performing “modern” total hip replacements for almost a decade when Coventry officially implanted the first hip in America. FDA approval for medical devices would become much more stringent after the Dalkon Shield fiasco in 1976, and the Medical Device Amendments of 1976 (to the Food, Drug, and Cosmetic Act of 1938) greatly strengthened the federal government’s oversight of devices.
At the passage of the 1965 Medicare Act, there had been no total hip replacements performed in the United States. Because the AHRQ was only established in 1989, there is scant evidence about the volume of hip arthroplasty volumes prior to the 1990s. In the Mayo Database (formed in 1969 with the insertion of the first hip), there is precise information about joint replacement volume at the Mayo Clinic. At one of the world’s busiest joint replacement hospitals there was a total of 35,167 hip replacement operations from 1969 to 2000.5 Even though that number started slowly and ballooned, it only represents a little over one thousand hips per year. What has happened over the last few decades, then, is remarkable.
From the AHRQ’s NIS, there were 290,700 hip replacements in 1997 in America. By the year 2000, there were over 300,000 hips replaced in America; in 2005 there were 383,500. In 2007, in the JBJS, an investigation on the numbers of hip and knee replacements was conducted, and based upon the volumes and the changing demographics of America (i.e., the aging of the Baby Boomers), the authors predicted that by 2020 there would be 384,000 primary totals hip replacements and 67,600 revision hip operations.6 That number swells to 572,000 primary and 96,700 revision hip replacements per year by 2030. Those 2030 predictions represent a 137 percent increase over 2005. The striking observation in reading that 2007 article now is the degree to which the 2014 data blows away the predictions.
A December 2017 Statistical Brief by the AHRQ entitled, “Overview of Operating Room Procedures During Inpatient Stays in U.S. Hospitals, 2014” reports that in 2014 there were 522,800 hip replacement operations (not counting the nearly 300,000 operations for hip fractures, which are often treated with partial or total hip replacements).7 Therefore, in 2014, the 522,800 hip replacements is 16 percent more than the 451,600 predicted by 2020 in the JBJS. Even savvy statisticians miss the mark, consistently underestimating the impact of even commonly performed operations.
In patients sixty-five and over (almost 100 percent of whom have Medicare insurance), there were 315,400 hip replacement operations in 2014, representing the second most common operating room procedure among that age group.8 Hip replacements in 2014 were the third most costly inpatient stays in America, averaging over $17,000 per stay, which is over 5 percent of all costs associated with admission to US hospitals. As will be seen, pacemaker operations are twice as expensive, and heart valve operations are three times as expensive as hip replacement, but because they are less commonly performed are less costly overall than hip surgery. The aggregate costs for hip replacement hospitalization (not counting outpatient therapy and nursing) is over $8 billion dollars, which is, all by itself, more than the entire 1967 Medicare budget for hospital care. What started in a tiny workshop in Lancashire, northwest England, at the hands of Sir John Charnley, has grown into one of mankind’s most effective interventions, occurring almost one million times per year in America as you read this book, if you combine its use for arthritis and fracture. The old saying in orthopedics that “man enters life through the womb but exists through the hip” is not nearly as true as it used to be, and we can thank Charnley for that. It was cheaper to fold an afghan over the incapacitated legs of an invalid with a fracture—but not very effective or humane.
Total knee replacement numbers are more sobering. Arthroplasty of the knee is the second most expensive procedure in America, costing almost $12 billion in 2014.9 In fact, the six most commonly performed musculoskeletal operations account for one-quarter of aggregate costs of all inpatient stays in America, totaling $41.2 billion in 2014.10 In the year 2014, there were 723,100 total knee replacements performed in US operating rooms.11 The same 2007 JBJS article referenced above forecast 1,641,00 knee replacement operations by 2020 (7 percent of which are predicted to be revision operations), and 3,749,00 total knees by 2030 (of which 268,000 are estimated to be revision operations).12 Based on 2014 AHRQ data, wherein the average cost of knee arthroplasty is $16,300, treatment of knee arthritis alone in 2030 would be an astounding $61 billion dollars.
Shoulder replacement arthroplasty has ballooned at a rate over the last fifteen years unlike any other joint over the last half century. Charlie Neer’s original hemiarthroplasty underwent few changes throughout the 1950s and 1960s, and total shoulder replacement was still practiced by a small subset of orthopedic surgeons in the 1980s and into the 1990s. Throughout the 1990s, glenoid implant design had changed very little, but at the turn of the century a major change in the shape and style of fixation was proposed at several orthopedic implant manufacturers, both in Europe and in America. By 2006, total shoulder replacement finally surpassed partial shoulder replacement, and this trend has never reversed.
The number of total shoulder replacements doubled in a short few years around the time that the FDA approved reverse total shoulder replacements, in March 2004. This third segment has dramatically changed (and improved) the way orthopedic surgeons address arthritis, rotator cuff tears, fractures, and previously failed shoulder operations. Not surprisingly, the number of reverse replacements has exponentially grown since introduction just fifteen years ago. Combined, there were 66,485 shoulder implant operations in 2011, growing another 50 percent as this book goes to press.13
Elbow replacement entails either complete replacement of every bearing surface, or simple replacement of the radial head alone. In the United States, the annual rate of total elbow arthroplasty is 5,800 patients, while the rate of radial head replacement is 9,200. Combined, 15,000 patients undergo some type of major implantation of metal in their elbow every year in the United States.
Wrist and ankle replacement operations are relatively rare compared to hip and knee arthroplasty. Instead of hundreds of thousands of cases per year, there might be less than four hundred wrist replacement operations14 per year in the United States. The combined total of partial and total wrist replacement operations in 2014 was only two thousand cases.15 Total ankle arthroplasty is much more common, with an estimated 13,145 cases performed over an eleven-year span, from 2000–2010.16 There was an increase in total ankle procedures after 2006, but the number is still likely less than two thousand per year in the United States. Ankle fusion is much more common (perhaps six times), and requires a substantial number of metal screws, plates, and rods. It is reasonable to conclude that more than ten thousand patients a year in America require major implant surgery for serious ankle problems.
In the United States, there were approximately sixteen thousand thumb and finger replacement operations and twelve thousand toe replacement operations in 2014, according to SmartTRAK, an orthopedics industry analyst.17
In sum total, in the year 2014 (the most recent year for which we have the most reliable data), there were 522,800 total hip replacements, 723,100 total knee arthroplasties, 90,000 total shoulders, 15,000 elbow replacements, 16,000 thumb and finger replacements, 12,000 toe replacements, 2,000 ankle replacements, and 2,000 wrist replacements. The grand total of all joint replacements in America was 1,381,300 in 2014. There is a small subset of patients who received more than one joint replacement in a single calendar year, so it is not accurate to conclude that 1,381,300 unique Americans had a joint replaced in 2014, but until the United States. has a joint registry, this tabulation is as close to accurate as we may produce. This number will swell to roughly two million joint operations every year by the time this book goes to press and four million every year by the year 2030.
Spinal fusion surgery is the costliest inpatient operation in America. Although spine surgery cases are about half the volume of knee arthroplasty operations, the mean costs are almost double. In 2014, there were 413,200 inpatient stays for spinal fusion surgery, with nearly all requiring metal screws, plates, and/or rods.18 Although laminectomy or disc removal spine surgery is the fifteenth most expensive operation (with aggregate costs of $2.3 billion), these operations, which do not involve device insertion, are not central to this implant-focused tabulation. Nonetheless, spine fusion surgery is massively expensive, representing over 7 percent of all operating room costs in 2014.19 Because many spine operations are now performed on an outpatient basis, the above noted number of 413,200 spine operations vastly underestimates the actual number of operations performed. Cooperative industry tracking estimates compute the number of instrumented spine operations in 2014 as 778,180 operations.20 Roughly a half-million Americans have spinal implants inserted into their bodies annually, about a third of which (155,900) are between sixty-five and eighty-four, representing somewhere in the neighborhood of $4 billion of Medicare spending on spine fusion operations, saying nothing of the astronomical costs of nonoperative spine care and the sobering loss of productivity among American workers who suffer from a “bad back.”21
Bone fractures are treated either with nonoperative intervention (like casts, splints, and slings) or with open reduction and internal fixation. “Internal fixation” requires plates, screws, pins, and anchors. Every single bone in the body has certain types of fracture patterns that are best treated with implanted devices—to not have surgery is to sacrifice the eventual function of that limb. A wise surgeon knows which fractures to treat with a cast, and which ones demand an operation. The tabulation below is therefore exclusively a compilation of surgically treated fractures that have been addressed with implanted devices.
Fracture fixation of the upper extremities, including clavicle, shoulder, elbow, wrist, and finger device implantations, totaled 350,388 procedures in 2016.22 With an increase of about 25,000 such operations per year, a retrospective extrapolation of 300,000 internal fixation implantations in 2014 seems reasonable. A total of 1,862,134 internal fixation procedures were performed on the lower extremities in 2016, and assuming a 6 percent growth in internal fixations over the last decade, a total of 1,627,924 lower extremity implant-related cases were performed in 2014.23 These include tibia and femur fractures, ankle fractures, pelvis and hip fractures, and foot fractures. Combined, there were approximately 1,928,000 extremity fracture operations in the United States in 2014, not counting spine stabilization operations that were previously included above. By the year 2020, this is expected to pass three million internal fixation cases per year, due in large part to age-related hip and leg fractures among the population.
Sports medicine as a specialty started as knee reconstruction on football players. Today, sports medicine operations typically entail arthroscopically performed, minimally invasive operations on joints and their ligaments. Oftentimes these operations include multiple procedures performed together, most notably knee meniscus repair and ACL reconstruction. Therefore, the number of procedures is greater than the number of operations. Because the focus of this book is upon the impact of the implant revolution, and because I am driving toward an overall number of patients in America who have a device implanted in their bodies in a given year, combined procedures are counted as a single operation. This complicates an already daunting task of calculating the reach of the device industry, particularly in orthopedic sports medicine. No one truly knows the precise figure, but by cross-checking multiple sources, like industry reports, medical literature publications, insurance databases, and state and federal agency databases, the numbers get more reliable.
ACL reconstruction stabilizes the knee, and is typically performed on non-Medicare patients in an outpatient setting. Recent studies show a significant increase in the rate of ACL surgery over the last fifteen years. In 1994, the rate of surgery was 33 per 100,000 capita,24 increasing to 40.9 cases in 2004,25 and further increasing to 45.1 per 100,000 capita in 2006.26 That ten-year-old data equates to 134,421 ACL reconstruction operations per year. The US Census Bureau estimates that there were 318,646,275 people in America on July 4, 2014,27 which I will use to calculate numbers of procedures in this book. Even if the rate of 45.1 per 100,00 capita did not increase (unlikely), a total of 143,689 ACL reconstructions were estimated to have been performed in 2014. However, that number is a vast underestimate if compared to the market analysis performed by those “in the know.” In 2016, there were 493,328 knee ligament reconstructions (including 34,005 multi-ligament reconstruction operations).28 With a compound annual growth rate of 3.93 percent in knee ligament repair, an extrapolated number of 455,600 knee ligament reconstructions were performed in 2014, triple the number that would have been predicted from the medical literature a decade earlier.
There are over half a million knee arthroscopic operations per year in which a portion, or all, of the knee meniscus is removed. In 2014, there were 416,400 knee meniscus repair operations and 2,200 meniscus allograft (transplantation) operations.29 Surprisingly, with a total of 418,600 operations involving implantable devices, meniscus repair was almost as common as cuff repair.
Rotator cuff repair is an even more commonly performed operation. The rate of cuff repair was estimated to be 98 per 100,000 capita in 2006,30 equaling an estimated 312,228 cuff repairs in 2014, if we believe the rate has not increased. However, recent studies show a stunning growth in the rate of rotator cuff repair, with a 353 percent increase in cuff repair in Florida from 2000 to 2007, and a 238 percent rate increase from 1995 to 2009 in New York state. With Baby Boomers just now reaching Medicare age, and with comprehensive proof that rotator cuffs tear around that age, there is certain to be an explosion of cuff tear operations (all of which entail the use of implants). A (relatively) modest 60 percent increase since 2006 would equate to 500,000 cuff repairs in the year 2014, a figure that everyone in the orthopedic industry agrees that we have already achieved.
Shoulder stabilization surgery is usually performed on an outpatient basis, so NIS data is unusable. Utilizing commercial databases, authors calculated numbers of open and arthroscopic shoulder stabilization operations in large populations (more than a tenth of the US population). Extrapolating from these numbers, there were 30.7 shoulder stabilization operations per 100,000 capita in 2012, or an estimated 97,928 operations in the United States.31 With rates growing around one patient per 100,000 in that five-year span (2008–12), there were likely 100,000 shoulder stabilization operations in 2014, all of which require multiple surgical implants.
Arthroscopic repair of soft tissue elements of the hip was virtually nonexistent prior to 1990, and has been the fastest growing segment in sports medicine since 2000. In 2014, there were approximately 100,000 hip repair operations in the United States, all of which required permanent device implantation.32
Cartilage implant surgery involves implantation of whole or morcelized pieces of cartilage from one part of a patient’s body to an injured part, or from another patient—so called “allograft cartilage” implantation. In 2016, there were 15,452 cartilage replacement operations from one (deceased) donor to another patient.33 With an estimated 10 percent annual growth in operations, it is reasonable to estimate that 12,500 such cartilage implantations occurred in 2014.
Today there are numerous soft-tissue operations performed on every particular bit of real estate in the human body—from the little toe to the sternoclavicular joint at the breastbone. Combined, these cases approach several hundred thousand operations. Totaling these together with ACL reconstruction, cuff repair, meniscus repair, shoulder stabilization, hip surgery, and cartilage implantation, the US market was approximately two million procedures in 2014.
In 2014, the total number of operations by subject were:
Sports Medicine: 2,000,000
Fracture operations: 1,928,000
Joint replacement: 1,381,300
Spine instrumentation: 778,180
Combined, there were 6,087,480 orthopedic and spine device implantation operations in 2014.
The heart, lungs and great vessels are addressed by cardiothoracic surgeons, cardiologists, and vascular surgeons. Prior to angiography, cardiologists performed few procedures, but as minimally invasive techniques improve, cardiologists perform more interventions every year, some of which are nothing short of unbelievable.
Cardiothoracic surgeons specialize in performing “open-heart” surgery, with coronary artery bypass grafting (CABG), valve repair or replacement, lung resections, and treatment of the great vessels. While many lung operations are performed “thorascopically,” or with the use of endoscopic equipment and small incisions, most heart operations are performed via a thoracotomy, where the sternum, or chest bone, is split with a saw and the rib cage is (gruesomely) spread open with a metal cranking device. The heart and its neighbors lie in full view, accessible to surgeon’s hands and devices.
Valve surgery is most commonly performed on the aortic valve, followed by the mitral valve.34 Recent analysis shows that isolated valve surgery (operating on one valve in a single operations) occurs 89 percent of the time, while 11 percent of open-heart valve operations involve a combination of valve repair or replacements (most commonly the aortic and mitral valve together).35
Tricuspid valve surgery, like all valve surgery, entails either repair or replacement. Tricuspid valve replacement surgery is performed one thousand times per year in the United States, about half the time in concert with another heart procedure.36
There is a significant trend in repairing diseased mitral valves, instead of replacing them. For those undergoing replacement, there has been a definite trend in replacing the mitral valve with a xenograph (so called “bioprosthetic” animal valves) tissue graft instead of a mechanical heart valve.37 In cases of repair, permanent sutures and reinforcing implants are used; therefore, device implantation occurs with repair and replacement. In 2005 there were a total of 16,997 isolated mitral valve operations in the United States, with almost an equal distribution of repair and replacement.
Alternatively, in 2005, there were 28,360 isolated aortic valve operations, with 97 percent valve replacement operations and only 3 percent repair. Almost all the replaced valves are bioprosthetic, with fewer and fewer mechanical (metal) valve operations every year. In addition, like other valve operations, where there is a trend in multiple structures treated, there is an increase in the percentage of patients whose thoracic aorta is also addressed at the time that their aortic valve is replaced. A recent study showed 28.5 percent of patients with a bicuspid (congenitally malformed) aortic valve underwent surgery on their thoracic aorta. This is a threefold increase from 1998 to 2008, and represents a 7.5-fold increase in costs from $156 million to $1.2 billion in the same time span.38 The Harvard physicians who published this paper were able to demonstrate a meaningful change in mortality, but the study highlights how a simple change in attitude among surgeons results in a rapid, and expensive, ballooning in costs and device usage.
Attempting to decipher the number of valve operations per year based upon recent publications limits this author to patients at least a decade ago. The most recent clinical volumes among US cardiac surgeons represent the year 2007. In a 2011 publication, using the Society of Thoracic Surgeons (STS) database, a total of 292,543 valve operations were performed over the five-year period of 2003–07. Simple arithmetic yields an average of 58,509 operations per year. That squares with data from above-mentioned subtotals. There were about 45,000 isolated valve operations per year in the early 2000s, with at least ten thousand more combined valve operations. Unbelievably, in just one decade, that number has tripled to 143,500 valve operations in 2014,39 and with the Baby Boomers just reaching the average age of valve surgery patients (sixty-seven years),40 valve surgery promises to rapidly grow.
CABG is the most commonly performed open-heart operation, with 201,600 operations in the year 2014.41 There has been a trend over the last fifteen years of decreasing CABG numbers, in large part due to the ability of cardiologists of addressing coronary vessel disease “percutaneously,” or via a catheter in the femoral artery in the groin. It is likely that cardiologists will continue to address more heart conditions with minimally invasive technology, sometimes in a fashion that seems daring, impossible, and perhaps risky, as will be seen. CABG surgery is performed by “jumping” a stenotic (clogged) artery with a patient’s own vessel graft (vein from a leg or small artery from the chest wall). It is sewn in place with a polymer suture that is permanent. Although the suture is not the device around which the operation revolves, CABG cannot be reliably performed without modern polymer implants like polypropylene suture.
Pacemakers were first used sixty years ago, and have become the eleventh most expensive inpatient operation. In 2014, there were $2.8 billion in aggregate costs for inpatient stays, but a significant portion of pacemakers are placed on an outpatient basis.42 Recent analysis has shown the rate of pacemaker placement in 2009 had risen to 61.6 implantations per 100,000 capita, equating to 188,700 patients. Assuming no further growth in pacemaker placement (unlikely), pacemaker placement in 2014 would equal 194,346 patients. Steven Kurtz and his coworkers have shown that implantable cardioverter defibrillators (a device that senses an arrhythmia and shocks your heart back into normal rhythm) have approached a rate of about 40 percent that of pacemakers.43 Therefore, the 2014 volume of defibrillators could be estimated at 77,738. The total US volume of implantable electronic cardiac devices in 2014 is estimated to have been 272,000 devices. (A study by the European Society of Cardiology in 2015 showed 500,411 pacemakers and 85,289 implantable cardioverter defibrillators were implanted in 2013 in the greater European area.44 All taken together, the worldwide market for implantable electronic cardiac devices is set to exceed one million per year.)
Coronary artery stents are small, expandable cylindrical devices made of metal (and more recently, polymer) that open up coronary arteries. They have been in use almost a half century, at times facing intense scrutiny over their potential overuse. Initially made of bare metal, and now commonly coated with drugs that inhibit the formation of clot and scar tissue on the stent itself, stents are placed either following an acute heart attack or in cases of ischemic chest pain. Trying to determine the number of stenting operations per year with a semblance of accuracy may be one of the most challenging computations of this book. The New York Times reports that there are 500,000 such procedures per year,45 and USA Today quotes a Vanderbilt cardiologist estimating one million operations per year.46 Other estimates claim 700,000 stenting operations annually.47
The crux of the problem in analyzing stent implantations is the dual nature of inpatient and outpatient procedures and the large numbers of patients who are not of Medicare age. A recent report analyzed data from the Centers for Medicare & Medicaid Services from 2001 to 2008, concluding that there were 319,567 procedures in 2008.48 Alternatively, a Journal of the American Medical Association paper evaluated the NIS, including all adults, and concluded that 809,400 adults had stent placement in 2008.49 No more recent data analysis exists in the medical literature, and with the population aging, and stenting remaining popular, it is entirely reasonable that the real number is one million patients per year undergoing stenting per year in the United States. With over seventy companies manufacturing stents, the worldwide market is estimated at $12,000,000,000 (yes, $12 billion) annually.50
Device-related repair of large vessel aneurysms has dramatically decreased morbidity and mortality of the dreaded condition. After leaving the heart, the aorta is still as big as a garden hose, and if the wall of the great vessel weakens and balloons out, a patient can be on the precipice of death. Aneurysms can also occur in other vessels as they divide into the lower limbs. While only 2,000 such repairs occur every year,51 there are about 30,000 abdominal aortic aneurysms repaired each year, averaging the values of an estimated 26,257 cases in a survey of surgeons in 201352 and a computed number of 32,464 procedures among Medicare recipients in 2006.53 Combined, there were 32,000 aneurysm repairs in 2014.
The combined financial impact of stent placement, bypass grafting, heart valve, and pacemaker procedures was $23.4 billion dollars, in large part due to the high per case costs (e.g., $52,000 for heart valve surgery, $41,900 for bypass surgery, and $35,000 for pacemaker insertion).
In 2014, the total number of procedures per subsection were:
Coronary stents: 1,000,000
Pacemakers: 272,000
Coronary artery bypass graft: 201,600
Valve operations: 143,500
Aneurysm repair: 32,000
Combined, there were about 1,650,000 cases in 2014 involving the cardiovascular system.
Therefore, for musculoskeletal and cardiovascular systems, there were 7,737,000 operations in 2014.
A ventricular-peritoneal (VP) shunt is used to treat hydrocephalus, a condition of excess cerebrospinal fluid accumulation. A VP shunt is a thin piece of plastic tubing that is positioned deep in the brain and is tunneled under the skin, down the neck and into the abdominal cavity, where the excess fluid drains. There were 27,870 shunt-related procedures in 2000.54 A more recent study estimates 30,000 VP shunt procedures per year, and this will be used as a 2014 figure.55
The treatment of a brain aneurysm is either by applying a clip from outside the vessel via brain surgery, or by floating a tiny coil of tangled metal through the brain artery. By 2010, this was occurring six procedures per 100,000 Medicare enrollees,56 which in that year was 47.7 million people.57 That equates to 2,862 Medicare aneurysm treatments in a single year, but is estimated at 12,000 Americans per year in more recent literature.58
Neuromodulation devices target the brain, the spinal cord, or peripheral nerves. Neurostimulation devices were developed in the 1980s, based upon cardiac pacemaker-inspired prototypes, and not surprisingly, were first developed in Minnesota.59 Implantable devices deliver small amperage electrical pulses via tiny wires to the brain or to the spinal cord or peripheral nerves. Implantable drug pumps deliver small molecules to the central nervous system, allowing for neuromodulation of brain function.
Neuromodulation of brain function is called deep-brain stimulation (DBS) and is principally used to treat Parkinson’s disease, essential tremor, and epilepsy. Spinal cord stimulation (SCS) is primarily used to treat failed back syndrome, chronic regional pain, and peripheral nerve diseases. Peripheral nerve stimulation (PNS) is used to treat an interesting combination of diseases, like incontinence, migraines, obesity, obstructive sleep apnea, and abdominal problems.
DBS was approved by the FDA in 1997 for essential tremor, and in 2002, was indicated for Parkinson’s disease. As with other medical devices, the FDA allows for case-by-case use under the humanitarian device exemption (HDE), and with the demonstrated efficacy of DBS for Parkinson’s disease, the FDA granted exemptions for neurosurgeons to implant DBS devices for dystonia and obsessive-compulsive disorder.60 There is a growing list of off-label uses of DBS, including major depression, Tourette syndrome, anorexia, and even dementia. The most recent academic paper on the US trend of DBS devices estimated 5,385 implant operations in 2011, and based upon growth trends in the preceding years, an estimated 6,596 DBS devices were implanted in 2014 in the United States.
SCSs are typically placed by physicians who specialize in pain control, and in recent years those implantations occur in an outpatient setting, which, as always, complicates the computation of devices used. A scholarly article in Neuromodulation in 2009 concluded that 4,000 SCS systems are implanted each year in the United States; this was rebutted by a thoughtful letter by the immediate past president of the North American Neuromodulation Society, who concluded the 2007 number to be over 27,000 SCS implant operations—a stunning difference.61 The only recent credible source of neuromodulation device implantation rates comes from industry sources. One such report shows that, in 2014, there were approximately three times more spinal cord stimulators placed than deep-brain stimulators62; thus, in 2014, there were an estimated 20,000 SCSs placed in the United States. Similarly, there were 7,000 sacral nerve stimulator and 2,000 vagus nerve stimulator operations in 2014. All told, there were approximately 35,000 neuromodulation operations performed in America in 2014.
Combined, there were 77,000 central and peripheral nervous system implant operations in 2014.
The cochlear implant is perhaps the greatest success story among medical implantable devices. The only device to restore one of the five senses, the cochlear implant arguably achieves the most satisfying emotional results. The worldwide market for cochlear implants is about 50,000 devices per year, and as of December 2012, 28 percent of all cochlear devices have been implanted in the United States.63, 64 Therefore, an estimated 14,000 cochlear implants were inserted in the United States in 2014. There were also a small number of middle ear implants performed in that year, but this number is privately guarded by industry.
Sinus surgery, although common, entails the use of a temporary device, and therefore will not be included in this permanent implant calculation. Similarly, tympanic ear tubes are also temporary implants and not counted here.
The first successful kidney transplant was fifty years ago, but it wasn’t until the advent of powerful anti-rejection medicines like cyclosporine in the 1980s that organ transplantation in the United States and around the world was unleashed. America has, by far, the highest rates of organ transplantation of any country in the world. In the year 2014, there were 29,539 organ transplant operations in the United States.65 As opposed to every other data source in this chapter, this is an exact number, due to the supremacy of the United Network for Organ Sharing (UNOS) and its stellar record keeping and oversight powers. In 2014, there were 17,108 kidney transplants, 6,730 liver transplants, 2,655 heart transplant operations, and 1,925 lung transplant operations. All heart transplant operations are from deceased donors, but overall, about one-fifth of organ transplant operations are performed from a living donor, including one-third of all kidney operations.66
In vitro fertilization (IVF) is arguably the greatest life-giving operation known to mankind, as it is truly the creation of a human being in a laboratory setting. Beginner biology students learn about asexual reproduction among spores, bacteria, and many single-cell organisms. Except for rare examples of asexual reproduction among fish, amphibians, and even birds, animals develop from fertilized eggs; sexual fertilization (whatever form of copulation occurs) demands an interaction between male and female. Anonymous fertilization of numerous eggs by, say, a disinterested king salmon is the norm among lower invertebrates, but the creation of a mammal requires an intimate interaction among male and female—until now.
According to the CDC, there are about 72,000 live born infants every year in America arising from assisted reproductive technology (ART).67 Two centuries ago John Hunter achieved groundbreaking insight by pickling chicken eggs at varying stages of development, leading him to believe that humans also developed from eggs in utero. Now, in the last several decades, IVF technology has given modern man the ability to achieve a sort of asexual reproduction, resulting in 1.5 percent of American births68 and one million American “test tube” babies.69 One could argue that IVF embryos are temporary implants, but with the appreciation that fetal cells do cross the placental barrier, and bizarrely, independently exist in the host mother’s body, it is fair to say that ART does result in a permanent cellular implant, saying nothing of the millions of ART humans now inhabiting planet earth (perhaps even you, Dear Reader).
The inflatable penile implant is used in erectile dysfunction, but its use is actually decreasing, as more precise surgery is perhaps contributing to a lower incidence of surgery-associated impotence, even as the overall number of men suffering from erectile dysfunction has increased. Even with an aging population, the surgical volume of inflatable penile implants is only 5,000 per year in the United States.70
Urinary incontinence is much less common among males than females. Operations for men include placement of an artificial silicone sphincter or insertion of a sling implant to internally check the flow of urine. A recent study estimates approximately 2,500 such operations every year in the United States, which is slightly more than 1 percent of the national total of similar operations for women.71
In 2014, there were 1,428,800 intraocular operations performed at community hospitals in the United States.72 Essentially all lens replacement operations are performed in an ambulatory surgery setting, even if the operation is performed in a hospital. That million-and-a-half number is misleading, however, because many states do not require a full accounting of non-hospital owned surgery centers. Therefore, the data sources are incomplete, and the aggregate numbers included in NIS calculations are a vast underestimate of the number of cataract operations.
Like almost all implant trends in the United States, the rate of implantation of intraocular lenses has steadily increased since their introduction. Curiously, a 1986 article predicted that the number of lens implantations per year would decrease and level off to less than one million operations per year.73 In essentially all cases of device implantation, it is always a safer bet that the number of operations will increase, not decrease.
The true number of intraocular lens implantation operations per year is approximately 3,000,000 per year.74 More than 99 percent of cataract operations are on a single eye, with the second operation scheduled weeks later.75 Therefore, the number of American receiving lens implants on an annual basis is roughly 1,500,000.
Insulin pumps, (and the blood glucose monitors with which they interface) are not true implants, existing outside the body and connecting to the insides via infusion setups, small devices that are perched on the skin and have a tiny needle that crosses into the subcutaneous fat.
Prosthetic mesh is the most commonly implanted foreign material in general surgery, used as a permanent reinforcement in hernia surgery. There were approximately 190,000 inpatient abdominal wall surgeries in 2012, but the number of outpatient operations is vastly greater.76 It has been estimated that more than 80 percent of hernia repairs are performed with mesh,77 and there are more than 800,000 inguinal hernia operations per year in the United States.78 Commercial reports indicate that there are over 500,000 abdominal wall hernia operations per year,79 with a combined total of 1,300,000 hernia operations per year, of which at least one million hernia operations per year in the United States entail the use of permanent implanted mesh.
Gastric bypass surgery has changed and grown over the last several decades. Surgery is nothing short of a miracle for the nearly 200,000 people treated annually. The American Society for Metabolic and Bariatric Surgery estimates that 193,000 operations for weight loss were performed in 2014.80 More than 75 percent of bariatric operations involve nothing more than ingenious (crazy?) surgical transpositions of intestines and stomach. A small percentage of large metal and polymer devices are inserted into the belly of an obese patient, but in 2014 there were 193,000 bariatric operations, either using simple permanent surgery while sewing guts together, or using a band or other mechanical device to slow food down from being transferred or digested.81
The most common use of implants in gynecology is transvaginal mesh (TVM), used to treat pelvic organ prolapse (POP), a condition that most frequently affects women after pregnancy. There are an estimated 200,000 TVM operations performed every year in the United States.82 While POP is a common postpartum condition (approximately 10 percent of pregnancies),83 and TVM is ordinarily performed, the FDA in 2011 issued a safety communication stating that “the use of transvaginal mesh may put women at a higher risk of complications without increased benefit to their quality of life.”84
Urinary incontinence treatment is now most commonly treated with the use of a synthetic device that functions as a sling.85 Among American women aged eighteen to sixty-four, the rate of sling repair is 198.3 per 100,000 women; the rate for women older than sixty-five is even higher, perhaps 60 percent more.86 The total of sling operations for urinary incontinence is estimated at 215,000 women per year in the United States.
The American Society of Plastic Surgeons reported 286,254 breast augmentation operations in 2014.87 Most women choose silicone gel-filled implants, which were provisionally approved in 2006 by the FDA.88 Most other plastic surgery operations do not incorporate implants, including face eyelid surgery, breast reduction, and liposuction. Many plastic surgery operations entail the use of injected fillers that get degraded and removed by the body, or transfer of fat cells from other parts of one’s own body. Neither qualify as permanent implants
It has been estimated that 450,000 osseointegrated dental implants are placed every year in the United States.89 Gone are the days of exclusively relying upon dentures and dental adhesives. Instead, millions of patients have artificial teeth that are anchored to the bones of the skull with metal posts that cross the gums and bond with the bones.
In the United States, in the year 2014, there were:
6,087,000 orthopedic and spine device implantation operations
1,650,000 cases involving the cardiovascular system
77,000 central and peripheral nervous system implant operations
14,000 cochlear implants were inserted
29,539 organ transplant operations
72,000 live born infants every year from IVF
7,500 urological implants
3,000,000 lens operations
1,000,000 hernia operations entailing the use of permanent implanted mesh
193,000 bariatric operations
200,000 TVM operations performed
215,000 sling operations for female urinary incontinence
286,254 breast augmentation operations
450,000 osseointegrated dental implants
Therefore, in the United States in 2014, the total number of implant operations was about 13,280,000. Assuming a compound annualized growth rate of 4.5 percent (a very conservative growth rate), the number of implant-associated operations per year by the year 2020 would be 17,294,000.
As has been emphasized in this chapter, these calculations are occasionally educated guesses, but are far more scientific than anything that has ever been proposed. At the time of this writing, as we approach the year 2020, we, American citizens, politicians, employers, medical device manufacturers, hospital administrators, and healthcare workers, must shake off our somnolence and deal with the fact that implant-oriented surgery is expensive, particularly when things go wrong. I am fortunate to have a very busy total shoulder replacement practice, and I delight in the implant revolution, humbly recognizing the pioneers who, with great insight and courage, imagined the synthesis of metals, drugs, plastics, and dexterous technique that allows surgeons to so powerfully free our patients from the necessities and miseries of life. But our conversation about healthcare reform and the future of medicine must be based upon facts—and the fact is that by 2020 there will be over 17,000,000 implant-oriented operations in America.