TKR - One or Two at a Time? Save

His would-be surgeon tried mightily to talk him out of a bilateral knee replacement. At 340 pounds, the patient's BMI -- above 43 -- was a significant contraindication. 

But the patient -- Nick Yphantides, MD, chief medical officer for California's San Diego County -- told MedPage Today he "aggressively" insisted, threatening to find another surgeon if he had to.

Osteoarthritis (OA) in both knees had so hobbled Yphantides that at one point, he couldn't walk to his car. What with the stress of grappling with county health issues, including its complex homeless problem and well-publicized hepatitis A outbreak that killed 20 and hospitalized hundreds and prompted a grand jury investigation in 2017.

His pledge to diet and exercise took a back seat.

Last July, Yphantides joined the growing number of people with debilitating OA pain who've opted to get both diseased knees replaced at the same time, during the same surgery, rather than spread out the ordeal over months. There's just one recovery period to suffer through, less time off work, and less time being incapacitated and requiring supportive care. Plus, in most cases it costs less, for the patient and the provider.

That's in part because under most payers' rules, doctors get half their regular fee for replacing the second knee in bilateral surgery (CPT 27447 with a usually-required 50 modifier).

Some surgeons around the country highly recommend it if the patient is healthy enough and meets whatever criteria are at play, which varies depending on the institution, surgeon, or health plan. For example, some surgeons say their systems have a hard cutoff for anyone over age 75 or with a BMI of 35 or 40, while others talked about their oldest bilateral patients being 88 and 92. It is, most surgeons told MedPage Today, a shared-decision making process.

Criteria for who gets surgery "is completely practice- and surgeon-dependent," said orthopedic surgeon Derek Ward, MD, of the University of California, San Francisco.

According to the American Association of Osteopathic Surgeons, studies suggest 3%-6.5% of the more than 700,000 patients who undergo knee replacement each year are having both knees done "simultaneously," which means during the same day and same anesthetic administration. That means the number of people living with this decision is expanding by as many as 45,000 a year.

'Why did you let me do this?'

Yphantides said the surgeon, Joseph Jankiewicz, MD, shook his head: "Nick, I'm telling you. After this surgery, you're going to be saying, 'why did you let me do this?'" But he ultimately agreed, although Sharp HealthCare in San Diego rarely does them and discourages it.

Indeed, the experience was "brutally rough," he said, with an unanticipated outcome of postural hypotension requiring him to stay bedridden longer than usual, a residual complication from pain medication, and an infection scare when a dressing came loose in the shower.

It wasn't just because of his job in the nation's fifth largest county. Yphantides, 53, is a single father raising two young girls, and couldn't not be there for them while recovering from another surgery the following year.

But he's very glad he went through it. "They made an exception for me," he said.

But simultaneous bilateral total knee arthroplasty (SBTKA) is a procedure that most surgeons interviewed spoke about with caution. It comes with higher risks of serious complications compared with spacing each surgery six or 12 months apart -- enough to be concerned about. All emphasized that all their patients know that.

There's also the potential for serious falls since the patient has, literally, no good leg to stand on for several weeks, turning essential tasks like getting up from the toilet into a "brutally painful" and precarious adventure, Yphantides noted.

Data unclear

Various studies and registries have tried to quantify the risks with varying conclusions. Some say outright the issue is controversial, and up for debate. One French study from 2012 concluded the risks weren't greater compared with a single knee replacement, saying "there is no solid evidence to prevent recommending this strategy."

Another from 2015 suggested patients weren't more likely to die in 30 days with same-day bilateral knee replacements, but it also found they were three times more likely to develop minor complications and twice as likely to have major ones, including anemia and blood transfusions, than patients with staged surgeries.

A third study compared 371 patients with SBTKA to a cohort with staged TKA six months apart and found no difference in length of stay and complications including respiratory arrest, pulmonary embolism, and surgical site infection, however, transfusion rates were higher for SBTKA recipients.

"The data is all over the place and unclear," said Michael Day, MD, an orthopedic surgeon at Summit Health in Chambersburg, Pennsylvania, and one of the authors of the third study. He's much more cautious about performing bilaterals and did only one last year.

"The data has not really been able to give us the answer to these questions" about risk, he said.

At UCSF, Derek Ward has been trying to make sense of the issue by pulling data from major institutional registries in six states from 2005 to 2014. From that work, he said comparative risks are slightly greater with SBTKA. The risk of developing deep vein thrombosis is an estimated 3.6% for a bilateral replacement compared with 2.8% for a single knee. Also, 30-day mortality is double with SBTKA, but that means it goes from one patient per 1,000 to two. He's now looking to quantify risks for a host of other potential complications.

These comparisons, of course, don't take into account that patients undergoing staged procedures are subject to those risks twice. That doesn't mean the risks exactly double with a second surgery, though, and selection criteria for the two approaches may differ such that patients considered at greater risk for complications would have been steered to staged surgeries.

Several surgeons said that if the patients are carefully selected and healthy, SBTKAs pose no greater risk.

"The complication rate really washes away and is almost the same" when a patient has two hospitalizations instead of one, said Steven Copp, MD, chairman of the departments of orthopedics and surgery at Scripps Green Hospital in San Diego. (His institution performed 212 SBTKA procedures in 2016-2017, the second highest number in California.)

Besides, he noted, many of the studies that have quantified risks were done years ago, when operative strategies took longer -- four or five hours for both knees -- exposing patients to greater risk and more time under anesthesia and prophylaxis.

"All that's changed substantially, and that has resulted in substantially less complications," he said. Now, bilateral knee replacements are completed in around two hours.

But half the pay 

Some doctors are extremely reluctant, or outright refuse to do SBTKAs on anyone and not just because of the higher complication rates, several told MedPage Today.

That's in part because payers reimburse surgeons half the full rate for replacing the second knee -- Medicare allows around $1,500 for CPT code 27447 -- during the same operation, which means a $2,250 allowance for both knees at the same time instead of $3,000 for two separate surgeries. Likewise, the hospital receives payment for only one admission under DRG 462, and may have to keep a double knee replacement patient in a bed one or two extra days instead of turning the bed over for another patient. Complications, should they occur, add to that cost.

At the Cleveland Clinic, orthopedic surgeon Kim Stearns, MD, believes he replaces both knees during the same surgery more often than any other Cleveland Clinic surgeon. He said he does roughly 10 knee replacement surgeries a week, and one in nine is done bilaterally. He considers it his "service line" specialty.

But he acknowledged, "it's kind of an unspoken thing, many surgeons don't like to do them because you get paid a lot less to do the second knee" compared with scheduling two surgeries over time.

But if patients are relatively healthy, under age 70, not diabetic, and not obese, the risks are very small, Stearns said. "I believe there are some patients who absolutely, to get better, they need to have both knees done at the same time."

Roger Robertson, MD, another Summit Health surgeon, said he performed knee replacement surgeries on 151 patients last year, including 43 with SBTKAs. Three-quarters of the latter went home the same day; only one went to a rehab facility after discharge.

Length of stay is exactly the same as for a single knee replacement, he said.

"Not a haircut"

But many surgeons stressed surgical assault on the body as a whole, is largely unknown and nothing to dismiss.

"This is not a haircut, this is a big deal," said Richard Iorio, MD, chief of adult reconstruction and total joint arthroplasty at Brigham and Women's Hospital in Boston. Iorio has performed bilateral knee surgery for more than 30 years. It requires "enormous cardiac workups," and if patients are overweight, they have to lose the excess.

Many surgeons have "cut back" on doing these, he said, and not just because of the lower reimbursement and perceived higher risk. "It's a long day at the office for the surgeon and a lot of resources for hospitals."

Medicare data, at least, seem to bear him out. A review of claims submitted for bilateral knee replacement, CPT 27447 with a modifier 50, dropped from 2013 to 2017 from 9,024 to 7,437, respectively.

Yphantides was not considered the best candidate for this surgery because of his weight. Though otherwise in good health, he said, he had regained much of the 270 pounds he lost 20 years ago during a well-publicized liquid diet odyssey; he rented a van to visit every baseball diamond in the country to interrupt his bad habits and wrote a book about the experience.

Most surgeons interviewed for this story said their hospitals or physician groups have a hard BMI cut-off of 40.

"Straight off the bat, a BMI over 40 basically is criteria for which you don't have surgery in general, and for joint arthroscopy, the risk for a poor outcome in that patient population is about three times what you would expect," said Copp of Scripps Green Hospital.

At his hospital, surgeon payment is not part of the discussion. Consideration is only given to "what's best for the patient," he said.

Nevertheless, some organizations seem to be advertising a specialty in bilateral knee replacement. For example, Abington-Jefferson Health in suburban Philadelphia maintains several websites touting patients' success with bilateral surgery.

Seventeen exclusion criteria 

At NYU Langone Health in New York City, any of 17 conditions automatically exclude a patient from bilateral surgery, said Joseph Zuckerman, MD, chair of orthopedic surgery, who performs 150 knee replacement surgeries a year. About 20% of those are SBTKAs.

Among the exclusions: age over 75, renal insufficiency, steroid dependent asthma or COPD, obstructive sleep apnea, or a Jehovah's Witness. And BMI over 40, of course.

Despite that, Zuckerman says the numbers of patients requesting bilateral knee replacement surgery at his hospital, and the number of surgeons willing to do them, is increasing. "While there is some potential increased risk, in properly selected patients it can be done safely. And I really believe there is quite a benefit to having both knees done at the same time, in the right patients."

Orthopedic surgeon Bill Macaulay, MD, also of NYU Langone, is more cautious. He said 30-day mortality is too high for bilateral than single knee replacement to risk it very often and only 7% of his patients last year had the bilateral procedure. Looking at all comers who meet NYU's criteria who have single knee surgery, the 30-day mortality is small, one in 5,000, he said. But with bilateral, that number jumps, "not just twice, but five times."

Ward, of UCSF, said "many physicians will not do a bilateral surgery if a patient's BMI is higher than 35."

Not all surgeons abide by hard cutoffs, however. Macaulay acknowledged performing one bilateral replacement on a patient who was 92. Robertson, at Summit Health, said his oldest bilateral patient was 88.

For Yphantides, now seven months later, the worst is over. "I'm absolutely thrilled I did it," he said. And if others have the option, he said, "absolutely go for it." But only if they have a lot of family support and are willing to bear the pain.