Twenty-five years ago, when Richard Berger, MD, began talking about outpatient joint replacement surgery, much of the orthopedic community found the idea absurd.
At the time, hip and knee replacement patients routinely spent seven to 10 days in the hospital recovering. Sending them home a few hours after surgery sounded reckless.
“Everyone said, first, you’re crazy, and second, it just can’t be done,” Dr. Berger said.
Today, outpatient joint replacement has become one of the defining shifts in the specialty. But when Dr. Berger performed his first outpatient hip replacement in 2001, the field still largely believed that recovery from joint replacement was dictated primarily by the trauma of cutting bone.
He believed the profession was focusing on the wrong problem.
“The popular belief at the time was that what we did with the bone was causing the majority of the pain and rehabilitation,” he said. “People thought what you did with the soft tissue was almost irrelevant.”
Dr. Berger, a hip and knee replacement surgeon with Chicago-based Midwest Orthopaedics at Rush and assistant professor at Rush University Medical Center, has performed more than 20,000 outpatient joint replacements, more than any orthopedic surgeon in the U.S.
With a background in mechanical engineering from Cambridge-based Massachusetts Institute of Technology, he spent years in cadaver labs redesigning instruments and refining techniques aimed at preserving muscles, tendons and ligaments during surgery rather than cutting through them.
“I spent a couple years going to the cadaver lab at all hours of the night practicing how to do the surgery better,” he said.
What he expected was incremental improvement, but instead, he discovered insights that fundamentally changed how orthopedics viewed recovery itself.
The moment orthopedics started changing
Dr. Berger initially believed minimally invasive surgery might improve recovery by 10% or 20%. Even that, he thought, would matter.
“If I was having surgery, I’d want somebody to make it 10 or 20% better,” he said. “Wouldn’t that be fantastic?”
But after performing his first minimally invasive hip replacements under a tightly monitored Institutional Review Board study, patients recovered far faster than he anticipated: “So much better that I was planning on keeping them in the hospital for seven days, and they were walking around after a day asking, ‘Why am I staying here another six days?’” he said.
As his surgical technique improved, recovery accelerated further.
“If I did the surgery in the morning, by that evening they were walking around, they passed physical therapy and they felt good,” Dr. Berger said. “They’d ask, ‘Can I go home?’ and eventually I realized there was no reason they couldn’t. “Everyone freaked out because they thought I was sending patients home in wheelchairs unable to move,” he said. What many surgeons did not initially understand, he said, was how dramatically preserving soft tissue altered recovery.
“The majority of the problems people have postoperatively, both short-term and long-term, comes from disturbing the muscles, ligaments and tendons,” he said.
According to Dr. Berger, traditional approaches often left patients recovering not only from arthritis and bone preparation, but from extensive soft tissue trauma and scar formation.
“Scar tissue doesn’t work as well as native tissue,” he said. “Without cutting the muscles, ligaments and tendons, everything is faster.”
Why anesthesia mattered as much as surgery
As patients began recovering more quickly, Dr. Berger realized another problem: anesthesia protocols had never been designed around same-day discharge.
With most joint replacement patients expected to remain hospitalized for days, the side effects of anesthesia were considered less urgent.
“I started looking at the sports medicine rooms next to me,” he said. “They were using cleaner medications because their patients were going home. I said, ‘Wait, why are we doing completely different anesthesia?’”
Working with younger anesthesiologists willing to experiment with new protocols, Dr. Berger helped redesign perioperative medication strategies around rapid recovery rather than prolonged hospitalization.
“Suddenly patients not only felt better from their hip, they felt better overall,” he said. “They weren’t nauseated. They weren’t dizzy. They weren’t knocked out from the medications.”
The shift reinforced a philosophy that still shapes his practice today.
“Orthopedic surgeons need to understand this is a holistic system,” he said. “It’s not just about the surgery. It’s about the anesthesia, the medications, the recovery, how you talk to patients and what you prepare them for.”
What patients now expect from aging
Over time, Dr. Berger said, the expectations surrounding aging and mobility have transformed as dramatically as the surgeries themselves. In previous generations, many patients accepted arthritis as an unavoidable part of getting older.
“People thought, ‘I’ve got arthritis, I’ll use a cane, take some pills and slow down,’” he said. “Today’s patients don’t accept that anymore, and they shouldn’t.”
His patients now include marathon runners, triathletes, professional athletes and highly active older adults hoping to maintain lifestyles that previous generations may have abandoned. One patient in his late 70s, he said, still competes in triathlons after bilateral knee replacements.
Another recently returned to his office nearly 25 years after outpatient hip replacement surgery and demonstrated that he could still run both forward and backward at age 80.
“He still runs 20 miles a week,” Dr. Berger said. “He still competes. Twenty-five years later, it still works.” But some of the most meaningful outcomes, he said, have little to do with elite athletics.
“I had a woman in tears because for the first time in years she could walk downstairs and do her laundry,” he said. “For her, that was climbing Mount Everest.”
He compares severe arthritis to the isolation many people experienced during COVID-19 lockdowns.
“You stop wanting to leave the house because everything hurts,” he said. “Your life starts closing in on you.”
Joint replacement, he believes, restores more than mobility. “It gives people their life back,” he said.
What ‘minimally invasive’ really means
As outpatient joint replacement expanded nationally, terms like “minimally invasive” and “robotic surgery” have increasingly become marketing language rather than meaningful clinical distinctions.
He recalls visiting another surgeon years ago who advertised minimally invasive hip replacement while still making what Dr. Berger described as a foot-long incision and cutting through soft tissue structures.
“He told me, ‘I used to make a 16-inch incision, and now I make a 12-inch incision. That’s minimally invasive,’” Dr. Berger said.
For Dr. Berger, true minimally invasive surgery means preserving muscles, ligaments and tendons entirely. “If you’re still cutting the muscles and tendons underneath, then it’s not really minimally invasive,” he said.
He expressed similar skepticism toward some robotic surgery claims.
“The robot does an okay job,” he said. “If you’re not a very skilled surgeon, doing okay is a step up. But if you’re already a very good surgeon, doing okay may actually be a step down.”
He compares robotics to paint-by-number artwork.
“If you’re a terrible artist, paint-by-numbers helps,” he said. “But if you’re already a great artist, paint-by-numbers can actually make the result worse.”
What orthopedics still hasn’t fully solved
Even after performing more than 20,000 outpatient joint replacements, Dr. Berger believes orthopedics still underestimates how much improvement comes from continual refinement rather than technology alone.
“There’s a lot of training that can still make people better surgeons,” he said. He worries that some surgeons increasingly rely on technology rather than improving their technique.
“Go to the cadaver lab. Go watch somebody else operate. Learn from other surgeons,” he said.
Even after decades in practice, he still visits other surgeons to study new techniques and challenge his own assumptions.
“I think I’m a great surgeon,” he said. “But I still go see other people all the time to try to learn something new.”
For Dr. Berger, the future of joint replacement will not come from any single technology or marketing trend, but from surgeons who remain willing to keep refining their craft long after they have mastered it.
At the Becker's 23rd Annual Spine, Orthopedic and Pain Management-Driven ASC + The Future of Spine Conference, taking place June 11-13 in Chicago, spine surgeons, orthopedic leaders and ASC executives will come together to explore minimally invasive techniques, ASC growth strategies and innovations shaping the future of outpatient spine care. Apply for complimentary registration now.
