Dr. Siverhus graces the cover of the HealthBeat Newsletter

News Archive (2011)

Bionic Knees - Advances in knee replacement implants and surgical and rehab techniques help speed recovery

John C. Lincoln Network, HealthBeat Newsletter
July - August 2011

Glendale resident Cheyrl Pound, 66, readily admits she should have had her knee replacement 10 years ago. “My right knee was very painful. I got gel and cortisone injections, and they didn’t work.”

Pound’s next step was a visit to Scott Siverhus, MD, an orthopedic surgeon on the medical staff at John C. Lincoln Deer Valley Hospital. After examining her right knee, he told her that arthritis had taken its toll; she needed a knee replacement. He performed the surgery on her right knee in December 2009 at the Deer Valley Hospital. In January 2011, he replaced her left knee joint.

“I was in the hospital four days the first time, three days the second time,” Pound said. “I walk fine now, with no cane. I’m still working on stairs; eventually, I’d like to not need the railing. But I can climb in and out of our motor home without pain now. And my range of motion is great.”


Less Tolerance for Painful

Joints As baby boomers age, the number of knee replacement surgeries is rising. “The fastest growing segment is 45- to 65-year-olds,” Dr. Siverhus said. “Patients today are less tolerant of pain and arthritic conditions. People are living longer and leading more active lives. As technology and surgical techniques have improved, patients’ and surgeons’ thresholds for worn-out and diseased joints have lessened. We can fix those joints.”

Implant technology improves  continually, he said, giving patients greater range of motion and function with a more natural feel. The metal and plastics are basically the same as 10 years ago, but companies are making the plastics more durable by removing oxidation through a variety of techniques. Most artificial joints will last 20-plus years.

“In round numbers, we’ll have to replace 2 percent at 10 years and 20 percent at 20 years,” Dr. Siverhus said. Is knee replacement surgery less invasive than 10 years ago? “When you’re putting half a pound of metal and plastic in a person, it’s really  never minimally invasive,” Dr. Siverhus said. “A typical incision today is four to six inches long. What we are able to do now is spare more of the soft tissues of the knee, including muscles and tendons.”

Computer Navigation Boosts Accuracy

In addition to implant improvements, surgical techniques have advanced in recent years. Dr. Siverhus is skilled in the use of computer navigation for knee replacement surgery.

“Computer navigation gives us a fixed point of reference above and below the knee,” he said. “An LED unit sends an infrared signal to a point at a designated distance from the operating table. Another LED light shows the parameters around the knee joint and at the ankle. Computer algorithms use this information to calculate the implant size and help us rebalance ligaments for the patient on the table.”

He noted that patients with arthritic knees often become bow-legged or knock-kneed because of pain. “We can realign those ligaments with the help of the computer and boost the accuracy of the installation.”

A small percentage of  patients, usually those who are younger, can be candidates for partial knee replacements. “This type of surgery has been around for 40 or 50 years,” he said. “Finding the right candidate for it is the challenge.” When only one of the knee’s three compartments is diseased or damaged, an orthopedic surgeon can choose to resurface that compartment only.

Pain Control and Rehabilitation

Dampening pain is another big advance for today’s knee replacement patients. “We now have a cocktail of different medications that we inject in the knee at the time of surgery. It provides lots of relief one to two days postsurgery, when pain typically is the greatest,” Dr. Siverhus said. With additional pain management protocols, patients get up and get moving sooner, lessening recovery time.

“The final challenge of knee replacement surgery, rehab, is typically down to six to eight weeks of physical therapy visits instead of three months, the norm 10 years ago,” Dr. Siverhus said.

Patients can continue to do required exercises at home to strengthen the knee and increase range of motion. Pound is more than pleased to be moving well again. “I’m much more mobile now,” she said. “I can be on my feet longer. Knowing what I know now, I would have done this much sooner.”

For more information, visit https://www.honorhealth.com/medical-services/orthopedics.

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"by Lesley Wright, The Arizona Republic.
May 6, 2011"