York Hospital is the first hospital in the Seacoast region and in the state of Maine to offer the robotic system for partial knee replacements. The equipment arrived in January and Dr. Akhilesh Sastry, a physician with Atlantic Orthopaedics and Sports Medicine, has already performed more than a dozen surgeries. Credit: Rich Beauchesne | The York Weekly

YORK, Maine — Dr. Akhilesh Sastry looks at a computer screen in a York Hospital operating room. His 74-year-old patient is getting a partial knee replacement, and days before, he had already performed this surgery virtually using 3D imaging. That day, he picks up a robotic arm tied to the computer, and man and machine together perform a precise, tailor-made surgical operation.

MAKOplasty, as the procedure is called, is considered revolutionary in orthopedics, the first significant advancement in partial knee replacements in more than 20 years, said Sastry. Patients of his said they experienced post-surgical “discomfort” instead of pain, a short recovery time of 4-8 weeks and “incredible” mobility.

York Hospital is the first hospital in the region and in the state of Maine to offer the robotic system for partial knee replacements. The equipment arrived in January and Sastry, a physician with Atlantic Orthopaedics and Sports Medicine, has already performed more than a dozen surgeries.

“It’s an extremely effective and accurate navigation tool that will not allow me to deviate from the plan I set in place. The dynamic assessment in the operating room allows me to position the implant to within one millimeter of accuracy” — thinner than a single strand of hair, he said. “That’s simply not achievable with the human eye. That’s the amazing part about it. It’s customized for every patient so it absolutely fits perfectly.”

At 39, Sastry has already performed upwards of 2,000 total joint replacements and more than 200 partial knee replacement surgeries. He has an engaging personality and can actually describe his job and the job of MAKOplasty in simple terms.

He said when a knee needs to be replaced, it’s due to arthritis, a “generic term” that means cartilage is being lost. Patients can present with osteoarthritis, rheumatoid arthritis and post-traumatic arthritis caused by an injury, for instance. The more load on the knee, the quicker the cartilage will deteriorate, he said.

He said the knee is broken into three compartments, and sometimes the cartilage is compromised in just one compartment — a situation that will likely call for a partial knee versus a total knee replacement. X-rays are taken, which allows the doctor to see the knee in two dimensions from the front and side. “And the bony cuts (in the operating room) are also in two dimensions,” in conventional partial knee replacements.

These surgeries have been performed since the 1980s, he said. The benefits are obvious: it’s less invasive, so pain is reduced and there’s an earlier return to function. Recovery time for a traditional operation is about 8-12 weeks, he said.

“Now comes robotic surgery,” said Sastry. “What the robotic arm allows us to do is get a 360-degree visualization of the knee.”

In a visit prior to surgery, sensors are attached to the patient’s knee which “triangulates” with the robotic system. A 3D mapping CT scan of the knee is then taken, and that model is placed on top of the simulated knee, he said.

“What the scan allows me to do is to operate on the knee before the patient even comes into the operating room. It allows me to look at the knee cap from top to bottom, bottom to top, front to back, rotate it in and rotate it to the side,” he said.

In this manner, he said, he is able to pinpoint with accuracy exactly how much diseased cartilage needs to be removed — no more and no less than necessary — with the result of “a customized knee that will fit like a hand in a glove.”

All this information is entered into the computer system and on the day of the surgery, he takes a probe and identifies markers on each of the bones that allow him to again triangulate the actual knee with the virtual knee.

“Here’s the amazing part. I can bring the knee through a range of motion from zero to 120 degrees and it will tell me if the knee is too tight or too loose or perfect — before I lay a hand on the bone,” he said. “Once I’ve determined it’s a smooth ride, I lock the robotic arm in place and I take out the diseased cartilage within the parameters I have set.”

On the day of surgery for his 74-year-old patient, there are two computer screens. One is being staffed by Alex Winkfield, a MAKOplasty product specialist from machine manufacturer Stryker Corporation. The other is in front of Sastry.

As he prepares to cut into the cartilage of his patient, the arm guides him and will not let him deviate from his “virtual operation.” The arm even works its way around two perfectly round pieces of cartilage that later create the “plugs” where the implant will be cemented into the bone. Watching the operation take place is a bit like watching a video game or similar animation.

Before cementing the implants he again puts the knee through a range of motions to make sure everything matches perfectly to within one millimeter of accuracy.

“If I like everything, I cement it in place and we’re done” — typically in less than 90 minutes — he said.

Timothy Yates of Wells was the first patient at York Hospital to undergo the robotic operation at the end of January. He said in mid-March, about six weeks out, “I’m pretty pain free. I have a full range of motion, and I stopped therapy about a week and a half ago.”

He said he was not nervous about the operation.

“Speaking with Dr. Sastry, I was pretty confident about it. He really knew what he was taking about,” said Yates.

And he now, when his knee is rested, gets a sense of what is in store for him soon.

“It feels like it did 40 years ago,” he said.

Sastry said York Hospital “is able to offer something so unique to the Seacoast that it is absolutely unparalleled. I do think they’re a pioneer of robotic surgery here. It definitely distinguishes them.”

“Dr. Sastry is an excellent physician,” said York Hospital president Jud Knox, “and we are convinced that this technology in his hands will produce the finest results for patients.”