Navio Surgical System improving knee surgery at St. Luke’s

By Dave DeWitte

Crop insurance adjuster Gary McCormick is back in the fields again with a knee that was partially rebuilt with robotic help less than two months ago.

“You wouldn’t be able to tell right now that I’d had the surgery,” said Mr. McCormick, 71, who was up and walking within hours after the partial knee replacement surgery at UnityPoint Health – St. Luke’s Hospital in Cedar Rapids on July 25, and was walking without a cane in a little more than four weeks with little difficulty.

The surgery was performed by Dr. Sandeep Munjal, orthopaedic surgeon at Physician’s Clinic of Iowa, using the hospital’s new Navio Surgical System. Mr. McCormick was only the second patient to have a partial knee replacement at St. Luke’s using the new robotic device.

Mr. McCormick had been farming and walking the fields with growing discomfort for years as osteoarthritis set into his left knee. The condition is essentially the wearing out of the cartilage that keeps the tibia (also known as the shinbone) and the femur (the thigh bone) from rubbing together in the knee.

Dr. Munjal found that Mr. McCormick was a good candidate for partial knee replacement rather than full knee replacement because the arthritis was on only one compartment, or section of the knee joint where the femur and tibia join together.

“We’re recapping the raw surface of the knee,” Dr. Munjal said.

When it is a viable alternative, partial knee replacement is often preferable to full knee replacement because it helps preserve the ligaments, unaffected cartilage and the natural alignment and movement of the knee, Dr. Munjal noted. It also reduces scarring, reduces healing time and avoids the radiation exposure of having a CT scan of the knee prior to surgery.

When a patient meets the criteria for a partial knee replacement, it is typically less expensive than a full knee replacement because it can be done on an outpatient basis, avoiding a hospital stay that can last a day or two. Post-operative medication and physical therapy costs are also typically lower, according to St. Luke’s.

The use of a Navio robot in the procedure saves the cost of a CT or MRI scan of the knee because the robot manually digitizes the knee during surgery, hospital officials said.

The cost of the Navio Surgical System was not disclosed.

Digital surgery

Mr. McCormick, of Anamosa, had a problem with the inside surface of his femur. He was offered the choice whether to have a full or partial knee replacement. Once the decision was narrowed to a partial knee replacement, he had the choice of having the procedure performed robotically or with more traditional surgical methods.

The Navio was Mr. McCormick’s choice.

“It’s less intrusive, faster recovery – it’s sort of cutting edge,” Mr. McCormick said. “I enjoy that kind of thing.”

The Navio robot uses a burr much like the one on a dental drill to strip away the small amount of bone needed to place the new cap on the bone, but what’s most intriguing is the way it is able to do so with more reliable accuracy and precision than an orthopaedic surgeon unaided by robotics.

Dr. Munjal compares the way the Navio works to Google’s self-driving car. During the navigation phase, the device digitally maps the knee and, with the surgeon’s input, determines the exact digital coordinates of the bone area to be stripped away.

During the next phase, the Navio “drives” the route with the cutting burr just as the Google car follows the coordinates on a digital map. The surgeon operates the robot, but the burr will not go outside the digital coordinates it has mapped for removal. A minimum of bone is removed.

Dr. Munjal said the most challenging aspect of learning to use the Navio was in understanding how to utilize its three-dimensional mapping functions. After the joint is mapped and the area of bone to be removed is plotted, the robot takes over most of the highly precise surgery.

Dr. Munjal expects a continuing growth in partial knee replacement procedures. That’s because members of the baby boom generation want to remain highly active later in life, performing activities such as running and downhill skiing that would not be advisable after full knee replacement.

“It suits their active lifestyles,” said Dr. Munjal.

Mr. McCormick doesn’t fit that profile, but he would like to continue working on his family’s farm and adjusting crop losses for at least another year or two.

Many robotic-assisted procedures such as partial knee replacement with the Navio are described as “minimally invasive” because they reduce negatives such as scarring and healing time, and require smaller incisions.

The left knee that received the procedure remained tender when Mr. McCormick walked on it in the weeks immediately after the procedure. He took physical therapy and used prescribed ice packs to improve the healing, but it was slow going at first. Around week four, the recovery accelerated and his knee began to feel better.

Robotic surgery is a growing trend in Corridor hospitals, but is not so commonly used in partial knee replacement surgeries. St. Luke’s is the only hospital in Iowa with the Navio Surgical System from Minneapolis-based Blue Belt Technologies, according to a hospital spokeswoman.

Blue Belt Technologies announced last month that the 500th partial knee replacement surgery with a Navio worldwide had been performed at Valley Baptist Hospital in Brownsville, Texas.