Full Metal Socket

How seniors became cyborgs.

Read more from Slate’s Geezers Issue.

Arnold Schwarzenegger 

Twenty-four years ago, Arnold Schwarzenegger starred in The Terminator, a movie about a cyborg —part man, part machine—sent back in time from the year 2029. He was young and buff, and the movie became his shtick. Campaigning for then-Vice President George Bush, he joked, “When it comes to the American future, Michael Dukakis will be the real Terminator.”

Today, Schwarzenegger is 61, and the joke’s on him. The cyborgs have arrived, and he’s one of them. He’s had a hip and two heart valves replaced, plus a femur repaired with screws, cables, and a metal plate. “This is what happens when you are the Terminator,” he quipped. “They switch body parts.”

In real life, cyborgs aren’t studs from the future. They’re old folks. As we age, our parts wear out. That used to mean immobility or death. Today, we can replace them. Bush had a hip switched out at 76, skydived on his 80th birthday, and got the other hip switched out at 82. Barbara Bush has an artificial hip; Cindy McCain has an artificial knee. The right arm of Sen. Daniel Inouye, lost when he was a soldier in World War II, is gone for good. But the left shoulder, which wore out five years ago at age 79, has been replaced.

Millions of Americans are walking around with artificial body parts. According to a U.S. government report, from 1997 to 2005, the annual tally of hip replacements increased from 290,000 to 383,000. Knee replacements increased from 328,000 to 555,000. Throw in another 50,000 to 55,000 shoulder replacements and other “arthroplasties,” and you’re looking at 1 million surgeries per year. “The demand for these procedures is projected to double in the next two decades,” says the report. The average artificial knee recipient is 66; the average artificial hip recipient is 70.

And that’s just joints. Nearly 2 million Americans are amputees, thanks largely to diabetes. Around 2 million people worldwide, including Dick Cheney, have implants that monitor and regulate their heartbeats. Some 100,000 have cochlear implants, which restore hearing. Others have artificial hearts, heart valves, elbows, or spinal discs. And, of course, teeth.

This is only the beginning. Artificial hands, eyes, lungs, pancreases, and “bio-artificial” kidneys  are well into development. The baby boom has aged into a bionics boom. The current global market for implantable defibrillators is around $6 billion. A study published two weeks ago calculates that 45 percent of Americans—135 million people—will end up with painful knee arthritis. Collectively, three corporations that specialize in implantable medical devices—Medtronic, Stryker, and Zimmer—already match the combined market value of General Motors, Ford, Sears, Dell, and Sony.

The industry is booming because it combines two things. One is the efficiency, versatility, and innovation of high-tech engineering. The other is the world’s most powerful desire: to live longer and more comfortably. The market for replacement body parts is like the market for car or computer parts, except that your body is paramount, and you can’t get a new one.

The merger of medicine with engineering is wonderful. But it also brings new problems. The first is that our technological reach exceeds our economic grasp. Depending on how you count, hip and knee replacements cost $15,000 to $30,000  or more. Prosthetic limbs can run $3,000 to $50,000. Cochlear implants cost around $40,000; implantable heart defibrillators cost $25,000; implantable artificial hearts go for around $250,000. Medicare covers 60 percent  of hip and knee replacements and 80 percent  of prosthetic limbs. Can we afford all these devices? If not, are we consigning some people to disability and death?

Second, the devices don’t always work. Some spinal discs have flunked regulatory scrutiny. People with ceramic hips have complained of squeaking. Defibrillators have even been recalled due to bad wiring. You can fix a squeaky bike, but what about a squeaky hip? You can take a bum cell phone back to the store, but what about a heart implant? What do you do when the product you want to return is part of your body?

Even when implants work, they wear out, as most household devices do. Hip replacements often have to be repeated. Heart pumps can give out. Last year, Cheney had surgery to switch out the power components in his defibrillator because, as a press aide dryly explained, “the device’s battery has reached the level where elective replacement of the device is recommended.”

Bionic parts bring new privacy questions. Wireless devices will let your doctor monitor your health without even a phone call. Will they give your insurer the same access? And what about complete strangers? Earlier this year, researchers demonstrated that implanted defibrillators could be hacked.

Then there’s the sticky question of turning off the machine. A life-support apparatus at your bedside is distinct from you. But what about an implant? If you want to die, and your defibrillator keeps shocking you back to life, can your spouse or doctor turn it off? Is that assisted suicide? Who has the right to terminate a Terminator?

Twelve years after The Terminator came out, another actor, Al Franken, offered a modest proposal: “Why not shoot the elderly into space?” That way, we could explore without worry. “I’m not saying we don’t try to get them back,” he joked. “We just don’t make such a big deal about it.” Today, another 12 years later, Franken, like Schwarzenegger, is an aging politician. And here’s the punch line: We’re not shooting the elderly into space. We’re shooting them into time. We’re testing cyborg gadgetry on them because they’re the ones whose parts have worn out. If it works, they’re exploring the future. And if it doesn’t, no big deal.