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Stunning Advances in Joint Replacement Surgery

By PAMELA DITTMER MCKUEN

When Sean Toohey of River Forest felt the first painful stings in his left hip, he wasn’t overly concerned. He chalked it up to a touch of arthritis—a family trait—or a bit of sciatica. He was too young for anything serious, he figured. But the pain grew worse. It didn’t respond to over-the-counter medications, and he couldn’t get comfortable to sleep. Then he had to give up his beloved golf game. It was time for a new hip.
  
Last July Toohey, 54, underwent a total hip replacement at Loyola University Medical Center. His orthopedic surgeon, Harold Rees, M.D., used an innovative technique called the anterior approach. He met the joint through a small incision in front of the hip rather than the traditional way of going in from the back. Fifteen days later the patient returned to his job as a floor broker at the Chicago Board of Trade.
 
“I am above and beyond happy,” he said. “I had no pain and no discomfort. Immediately after the surgery I was able to stand and walk. The next day I went up a full flight of stairs.”
 
Toohey, who is eagerly awaiting the 2013 golf season, is among the growing number of Americans who have had joint replacement surgery. It’s a trend sure to continue, driven by both improved supply and strong demand. On the medical side of the equation are greater sophistication of artificial joints, or “implants,” and new, less invasive procedures. On the patient side are factors such as obesity, which stresses joints, and longevity, which wears them out. Then there are the aging Baby Boomers, who plan to stay young and active forever.
 
Just during this century the growth is impressive. According to the American Academy of Orthopaedic Surgeons (AAOS), the number of total knee replacements in the United States more than doubled between 2000 and 2010, from 282,350 to 658,340. The number of total hip replacements rose from 165,065 to 302,839.
 
Replacement of smaller joints soared even higher: Total shoulder replacements increased from 7,223 to 39,226, and total ankle replacements increased from 844 to 2,608.
 
Historically speaking, knees and hips, which are the joints that most impact personal mobility, have the longest track record of replacement and highest success rates. In earlier stages of evolution are replacements of smaller joints including elbows, ankles, wrists and knuckles. Those outcomes are less predictable.
 
Knee and hip replacements are “among the most successful interventions in medicine,” said orthopedic surgeon Joshua Jacobs, M.D., AAOS president-elect and chairman of the Department of Orthopaedic Surgery at Rush University Medical Center. “They are a reliable way of getting people back to the activities they want to do, even though it is a big surgery. Probably the only other surgery with a better outcome rate is cataract surgery.”
 
Another trend is that many patients are younger than in decades past. They have strained their joints through active living, and are less inclined to endure years of pain before seeking relief.
 
“We used to say anyone under 65 is not a good candidate,” said Dr. Rees, an assistant professor at the Stritch School of Medicine. “But if someone is in the 40s and has problems in a joint, and we can’t offer anything better, it doesn’t make sense to make someone suffer for 20 years.”
   
The downside is, because implants have limited lifespans, younger patients probably will need their replacements replaced down the road. That’s called revision surgery...

Nicholas Kerr, 56, of Lansing has had two hip replacements and one do-over. He’s an outdoorsy kind of guy and an AT&T telephone lineman, a profession that requires him to climb ladders and utility poles. Painful arthritis set in a few years ago and steadily grew more severe until it curtailed his range of motion. He had his left hip done in 2006, but it kept dislocating—perhaps because he overworked it, he admits. Three years later he had a revision, and in December had the right hip replaced. His orthopedic surgeon for the latter two replacements was David Manning, M.D. at Northwestern Memorial Hospital. Dr. Manning’s preferred technique is the mini-incision posterior approach.
 
“The minute I came out of surgery, it was like I was never there,” said Kerr. “I could lift my leg with no pain at all. I was pretty impressed.”
 
“Recovery is not the same arduous journey that it was,” said Dr. Manning, associate professor of orthopedic surgery at Northwestern University Feinberg School of Medicine.
   
“Milestones like getting off the walker and onto crutches happen in a matter of weeks, not months. Hospital stays are significantly shortened. Physical therapy is shortened.” While the basic principles of replacement surgery haven’t changed, huge advances have been made in the hardware.
 
“Modern plastics have added significantly to the longevity of implants,” said Dr. Manning. “How long we can’t tell you until we get there.”
 
Implants also are increasingly customized to accommodate patients’ varying bone structures and deterioration. Computer-aided design and modular components help assure a secure fit.
 
“Depending on the implant, each component might come in several sizes,” explained Linda Tian, a medical device analyst with business intelligence provider GlobalData in London. “Patient A might require a longer stem to achieve better stability, but Patient B does not.”
 
In the knee replacement arena is the TruMatch® Personalized Solutions by DePuy Synthes Joint Reconstruction. The system uses a CT scan and specialized software to create a virtual 3-D model of the patient’s knee and disease progression. Then a set of customized metal guides is made to assist the surgeon in positioning the implant.
 
“In the early days we used to just eyeball where to make the cuts,” said orthopedic surgeon Michael Collins, M.D., of Hinsdale Orthopaedic Associates.
 
The TruMatch® rationale is analogous to installing new tires on a car: proper alignment is necessary for even wear and optimal mileage.
  
“Short-term, we can see less blood loss and less pain,” said Dr.Collins, who has done about 500 surgeries using the system. “But the real anticipated benefits won’t be felt for 10, 20, 30 or more years.”
 
Patients with severe ankle pain also are seeing new progress. The mainstay surgery has long been fusion, which permanently bolts the ankle bones into position. The procedure usually mitigates the problem, but it restricts range of motion. The two lower foot joints compensate to facilitate walking. Wright Medical Technology’s recent INBONE® Total Ankle replacement system employs computer technology to build patient-specific implants.
 
“We’re coming into the Golden Age of total ankle replacement,” said podiatric surgeon Douglas Pacaccio, D.P.M., of Advanced Foot and Ankle Surgeons in Sycamore, who has adopted the system. “The technology has gotten much better at making precise implants that mimic more what a natural ankle does while putting less stress on the implant.”
 
It’s also an age of specialization, said Priya Radhakrishnan, a GlobalData medical devices analyst in Burlington, Mass. Surgeons focus their practices on certain types of replacements, implants and procedures based on their training and experiences. Although many perform both knee and hip replacements, few, if any, will claim proficiency in all types of replacements. And they shouldn’t.
 
“Compared to the hip, the ankle is a more complicated joint,” said Radhakrishnan. “The wrist is even more complicated. Orthopedic surgeons who do those surgeries are not generalists. They are fellowship-trained in that modality.”
 
“There are nuances to every implant and every joint,” agreed Dr. Pacaccio. “The guy who focuses on that joint understands those nuances to a better degree than someone who is not doing as much of it.”
  
By the same token, not every type of surgery, implant or technique is suitable for every patient. Even though ankle replacement is available, for example, fusion is often the better choice. Body mass, diabetes, neuropathy and degree of bone deformity must be taken into consideration. Even marathon runners are probably better off with fusion than replacement because implants won’t withstand the rigor.
 
“Decisions are made on a case-by-case basis,” said Dr. Pacaccio.
 
Another consideration is that custom implants are expensive, and reimbursement rates are unclear, said Radhakrishnan.
 
It’s also important to note that results aren’t certain. Infection, blood clots and implant loosening or breakage are rare, but they do occur. Some products have been recalled, as were metal-on-metal hip implants in 2010 because of the potential for generating toxic debris.
 
“There are some failures,” said Dr. Jacobs, who runs a research laboratory at Rush. “There also are growing expectations that these devices will function for the rest of your days and allow you to be infinitely active. That’s an aspirational goal, but it will take some work to get there.”
  
To reach that goal, a vast body of research is ongoing. Researchers continue to search for materials that further minimize wear and corrosion as well as better means of affixing implants to bones to further shorten recovery and therapy times, and improved technology for small joints. Other investigations are looking into biologic agents that can promote tissue healing and bone growth, and whether stem cells can be used to regenerate bone and cartilage.
  
“A lot of important developments are on the horizon,” said Dr. Jacobs.

Published: February 23, 2013
Issue: Winter 2013 Issue

Comments

Ankle replacement
Wondering since this article is 2 years old, how much progress has been made to reassure patients 65+ of the positive affects of total ankle replacement.
Betti Grevengoed, Jan-06-2016