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MED

Stryker's Mako Makes CNOS Surgeon a Robotic Convert

Oct 21, 2020 07:00AM ● By MED Magazine

Brian Johnson, MD, an orthopaedic surgeon with CNOS in Dakota Dunes, says he was never anxious to jump on the robotic "bandwagon". During his residency 14 years ago, Johnson took part in a study comparing robotic surgery to traditional instrumentation for knee replacement. 

"Back then, the tech was clunky and it took a long time," he says. "Most importantly, it didn't affect the outcomes for patients. So I had a healthy sense of skepticism for a long time."

Johnson was also unmoved by studies conducted by robot manufacturers in recent years showing a clinical benefit. It was not until the independent Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) released its own data in 2017 that he decided to take a more serious look at the robotic approach to knee replacement. 

"The Australian Registry is the best in the world and is completely independent," says Johnson. "Their data showed a clear difference. Not a hint of a difference, but a clear superiority for robotic-guided partial knee replacement." 

After seeing the Mako Robotic Arm Assisted Surgery system firsthand, and evaluating the independent research, Johnson says he was determined to help bring it to Siouxland. 

"The biggest advantage is that it allows you to balance the knee more precisely before you even make a cut," explains Johnson who has offered robotic knee surgery at CNOS for about a year. "Traditionally, you would make the cut and then adjust the soft tissue to balance it. Now you can balance it before you even make the cuts. That means you cut less soft tissue and disrupt less of the knee." 

The system lets the surgeon overlay a series of checkpoints with CT images to ensure precise placement of the array and ultra fine tuning of the joint position. 

"How many humans can take a pin and draw a perfect circle a thousand times in a row? No one can, but the robot can," says Johnson. "It allows you to implement exactly what's in your mind. It will not allow you to deviate from your own plan."

Johnson says the result is a safer, more precise operation, and a balanced, stable joint. This precision is especially critical with partial knees, which tend to have a higher failure rate than total knees. The data shows robotic partial knee replacements are lasting as long as total knees for the first time ever, giving more patients a shot at a "forgotten knee" - a joint so strong, flexible, and pain-free that the patient can simply forget that it was ever a problem.

"With the robotic partial knee, a lot more people end up with a forgotten knee," says Johnson. "The key is to get the baseplate as big as you can without compromising the ACL. The robot helps you do that. It can also simulate how the forces are going to go through the knee in that particular patient, so you can adjust by just a few millimeters."

Johnson is hopeful that this level of precision will also make a big difference for total knees, too, but the data is not in yet. In the meantime, he is working with Stryker to help develop a robotic procedure for the shoulder joint.