EVANSTON — Evanston Regional Hospital has now performed more than 100 joint replacements with the aid of a Mako robotic arm assisted machine. The system uses digital models to help surgeons plan and execute joint replacements based on a three-dimensional model within virtual boundaries.

“At the end of the day, I came home exhausted,” said the 100th Mako patient, Shannon Williams. She was suffering from the pain and exhaustion brought about by an arthritic knee, and sought medical aid after reaching a critical point. “I teach school and manage an after-school program at Uinta Meadows, so I stand a lot.” She said her knee pain had made her everyday life tiring. “I didn’t want to do anything, so I said, ‘Let’s get it done.’ … I was just physically very tired. I didn’t sleep, and my knees hurt a lot.”

Dr. Micah Pullins, Evanston Regional Hospital’s orthopedic surgeon, said, “Pain, especially knee pain, affects a lot of things. If you’re not sleeping enough, that will impact your pain sensors, your ability to heal … those sorts of things.”

Pullins also said that these symptoms can often lead to mental and emotional stress, which can also be difficult to combat with the lack of sleep knee pain can cause.

Pullins described why deteriorating knees can lead to exhaustion.

“With bad knee arthritis, your muscles have to work harder to support you when your knee is not mechanically working right. The amount of energy you’re expending when your knee is arthritic is a lot more than it is when it is not.” 

Dr. Pullins said that patients’ pain is often due to osteoarthritis.

“Wear and tear,” he said. “You wear out the cartilage inside your knees, and then that makes more roughened surfaces. Your knee gets imbalanced as far as ligaments are concerned.”

He explained that base of the joint collapses in arthritis cases, setting the supporting ligaments in unequal positions. He said that osteoarthritis is the most common diagnosis leading to a knee replacement.

Pullins said the robotic-assisted system sets parameters from which the sawblade, guided by Dr. Pullins, cannot depart. “There is less soft tissue trauma because I can’t leave those haptics that it sets.” The cuts are also more precise than those done by hand. 

Pullins then said that most knee replacements at Evanston Regional are performed using Press Fit knee components.

“Most knee replacements done in the U.S. use cemented knees. You use bone cement to cement the implants onto the bone. Press Fit knee implants have a porous coating on the back of them.”

He said the process consists of removing the diseased bone, placing the implant onto the knee and allowing the bone in the knee to grow into the implant coating.

“Now you’re eliminating one area where a total knee replacement can fail,” he said, “which is the bone cement interface. You use no cement.”

Another important component of a knee replacement is the balancing of the ligaments.

“The robotic-assisted total knee allows me to perfectly balance the ligaments so that they are the same tension, whether the knee is flexed or straight,” Pullins said. “That is a feeling that most people who get their knees replaced haven’t felt in a long time.”

These three elements help to expedite recovery, according to Pullins. “It’s a quicker time getting back to functioning normally,” he said.

When asked about his robotic surgeries’ margin for error, Pullins said, “I can’t think of one that hasn’t gone ideally. Part of the robotic-assisted total knee, total hip and partial knee replacement is a CAT scan of the body part, which is uploaded into a computer program, where I perform a virtual knee replacement. I input the size of the components I want, put them in the position I want and I make the cuts virtually.”

Pullins noted that some adjustments need to be made during surgery.

“The program doesn’t know what condition the ligaments are in, so I essentially show the computer what the ligaments are like, so now it knows the ligament condition,” he said.

Pullins then tests a range of motion using trial implants before implanting sterile components with the same dimensions.

Some operations are performed without robotic assistance, Pullins said.

“I will often perform a hip replacement after a hip fracture without the machine, in an urgent or emergent surgery,” he said.

In these cases, Pullins said time constraints make the machine ineffective, and he resorts to traditional methods.

Pullins said that, after years of experience replacing joints, the robot exceeded his expectations.

“Assimilating a new system into a total knee was much easier,” he said. “It was easier to add steps, take steps away and be able to use the system efficiently, and to have the surgery just as quickly in almost every case.”

He also noted that he had not foreseen the technological advancement when he was in medical school. “There’s no way I would have pictured anything to this degree during medical school, or even residency.”

Pullins said new applications and procedures are in the works for Mako systems.

“They’re coming out with total shoulder applications, total ankle applications, both surgeries we do here,” he said.

After having surgery to alleviate her pain, Williams said her recovery had been faster than those of her acquaintances.

“I had it done on May 24, and I went back to work on June 15,” she said. “I worked two days that week, then Monday through Friday or Monday through Thursday.” 

Williams claimed she had not been concerned to learn that a robot played a role in her surgery, thanks to Pullins’ explanation of the process and the preparatory assistance by hospital staff.

Another patient, Doug Quillinan, received a double knee replacement using the Mako system. Similarly to Williams, arthritic pain had driven him from his usual activities.

“I couldn’t play basketball with my son, go skiing and hiking — most of the things that you’d want to go do. Even moderate hiking was painful,” he told the Herald. 

Quillinan had spent more than a decade with chronic knee pain.

“It finally got to the point where they were locking up and not moving the way I wanted them to move, on top of being painful, so it was time to get them checked out again,” he said. 

Quillinan is a middle school teacher and his job, much like his favorite activities, became especially taxing on his knees. 

Quillinan’s breaking point was a hike in southern Utah.

“My knees locked up on me while I was on a path with a bunch of lava rock,” he recalled. “It scared me, actually. They locked up on this hill and I felt like I didn’t have control of my own body. It could have been bad.”

Quillinan received injections as a hopeful remedy, but to no avail. He also said he found the robotic joint procedure fascinating.

“It’s very unique to see something like that here in Evanston,” he said. “I didn’t realize that we had that here.”

Both patients noted the hospital’s continuity of care. Marketing Director Erica Bailey wrote a more detailed description.

“From the beginning to end, the ortho team, OR, inpatient recovery and physical therapy work hand-in-hand,” she said in an email. “One benefit of ERH versus larger facilities is that PT is literally across the hall and works with the patient immediately after surgery. It won’t take hours post-op to see the doctor during rounds, but instead the patient is seen and treated immediately, as though they are family.”