Custom fit implants
The latest technology in total knee replacement surgery is now custom fit implants.
“It’s one step above the robot in the sense that rather than taking an off-the-shelf implant and using the robot to put it in, we’re getting focused, specific guides, matched to the anatomy. This really will be the next wave of where we go in medicine,” van der Ven said.
Or, as fellow Baptist Health orthopedic surgeon Dr. Francisco Borja said, “Rather than fit the patient to the prosthesis, why not fit the implant to the patient?”
Surgeons take a CT scan of a patient’s knee, hip and ankle and send it to ConforMIS, a Boston-based medical device company specializing in converting CT data into implants that are precisely sized and shaped to conform to an individual’s exact topography.
“They create a virtual knee, which is your knee,” Borja said. “The consequence is these patients recover faster, they don’t have to have as much therapy and don’t have as much pain and move faster and more naturally. They are not fighting with their own soft tissues because of a decision I made in surgery. This has been made for you. This is a significant step forward for mechanical devices.”
Patients with serious medical issues, such as a heart condition, hypertension and other ailments may not be candidates for the ConforMIS custom knee. The prosthesis, once created, can only be used for that particular patient. If they are not suitable for surgery, the device can’t be used for someone else, Borja said.
There are no custom-fit hip implants yet, but Borja expects customization there to come in the near future.
Partial knee replacement
Customized cutting tools tailored to the individual patient’s bone topography also make knee surgeries more accurate, Umlas said.
The knee is made up of three compartments — medial, the side of the knee closest to the body’s center; lateral, the side of the knee to the outside of the body; and the patellofemoral compartment, behind the knee cap. When only one portion of the knee is affected by arthritis, a partial knee replacement can be performed.
“What’s exciting about that is a partial can be done as an outpatient, or, at most, one night in the hospital, and so the recovery is much quicker than a total knee,” said Dr. John Uribe, medical director of Doctors Hospital Center for Orthopedics & Sports Medicine and chairman of the orthopedic department at Florida International University School of Medicine.
“With partial knee replacements, it’s a much less mechanical feeling … more natural,” Uribe said.
With boomers and seniors living longer and active longer, knee and hip replacement surgeries are common procedures in the United States, with about 719,000 knee replacements and 332,000 hip replacements in 2010, according to the Centers for Disease Control and Prevention. These numbers are projected to grow significantly over the next 15 to 20 years.
“New technology has always been an exciting part of our profession,” said Dr. Raymond P. Robinson, chief of Joint Reconstruction and professor of Clinical Orthopaedics at the University of Miami Miller School of Medicine. “Companies and physicians frequently introduce these new technologies with great excitement and fanfare. The hard part is determining which of these actually advance the results and outcomes for our patients.
“For example, contemporary total knee replacement performed with today’s modern techniques result in 97 percent good or excellent results and implants of best design are lasting more than 30 years in actual patients,” Robinson said. “When the excitement of the ever-present new technology subsides all too often the only ones left are the patient, their implant, and hopefully the surgeon who did the operation. Long-term clinical outcome measurements are key in determining which technologies actually improve the care of our patients.”
The good news?
“Less pain the day after surgery than the day before surgery. Life is motion. Most people have places to go, places to see,” Umlas said.
“I had a woman who was 96 who was told she was too old to have this [hip] surgery. Age is not a parameter, it’s about health,” Umlas said. “I saw her six months after surgery. She walked in feeling great and came in with a new boyfriend. She said she was denied a lot of fun in life because doctors had judged she can’t be helped. Within a day of her surgery she was feeling better than before her operation and in six months was walking independently. That’s what makes this rewarding, to restore function to people.”
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