Robotic technology is rapidly spreading across surgical subspecialties and in the past few years has begun to revolutionize joint replacement. While robots being involved in surgery may seem unnerving and like science fiction at first, the robot is actually not as involved as one might think. The surgeon still does all the work, the robot just functions to make the surgeons movements more precise. To understand how it works, let’s talk about what is involved in a surgery without a robot.


What is Involved in a Regular Knee Replacement?

In every knee replacement, worn out structures are removed and replaced with metal and plastic components. In the modern era this usually involves less than a centimeter being removed from each bone and resurfaced with metal. In other words, only the tips or end of the bone rather than large chunks of bone are what is replaced. The goal is to restore proper limb alignment, mechanics, and joint spacing thereby restoring range of motion and relieving pain with physical activity.

Left – This is an xray of a replaced knee viewed from the front. The white portions are the metal parts, and the plastic is invisible on xrays and represents a clear black space between the bones. Right – A knee replacement viewed from the side

What is Robotic Knee Replacement and How Does it Differ from a Traditional Replacement?

A knee replacement done with assistance of a robot uses the same final implants and mechanical principles as traditional knee replacements, but the robot is used to make sure that the pieces go into the perfect position for each patient. The goal is to give the surgeon more real-time information to make decisions and reduce outliers in the final product. The robot helps to determine where exactly to make bone cuts, at what angles, and without injuring nearby structures.


Why Would a Robot be Used?

Every knee and the reason for surgery is unique. Traditional surgical techniques try to accommodate for variance in individual anatomy and deformity, but the technology is an inexact science and is not always accurate. Improper placement of knee components can lead to further surgery and the hope is that with a more accurate robotic technique, a knee will feel better more quickly and last longer.



A view of the information provided by the robotic software, used in planning the knee replacement

How is the Robot Used?

First of all, it is important to emphasize that a robot is in no way autonomous. They only work when in the hands of the surgeon and only when and how they are instructed, usually with a trigger type activation device. In most cases, as with the Stryker Mako system, the “robot” is a machine with a mechanized arm. Attached to the robotic arm is a cutting blade that shapes the bone to accept the replacement parts as it is guided by the surgeon. This arm is coupled with a computer. The software allows the pieces to be more accurately planned in 3D space than typical traditional planning jigs and instruments. The robot allows your surgeon to create a plan with more information than ever before and then execute that plan exactly as intended. It lets your surgeon make a plan and follow through with it for your knee

Is there any Proven Benefit?

The Stryker Mako Robot

Robotic technology has the potential to reduce outliers. While the technology is new to orthopedic surgery it is already showing benefits. Theoretically robotics could lead to less repeat surgery, less pain and medication use from less soft tissue trauma, less bleeding and transfusions, and more. Some of these benefits are already being borne out in medical research studies, others will take time to see. There are a few disadvantages as well. For instance, most robotic platforms require extra xrays or scans before surgery. As a result it does have the potential of more cost per procedure, but this may be worth it if it decreases subsequent surgeries.


How do I Learn More?

In my practice I routinely employ robotics in surgery as I feel this provides a consistent result for the patient every time. At this point, robotics assistance is available in partial knee replacements, full knee replacements, and even hip replacements. Please make an appointment and I would be happy to discuss your knee and explain the procedure if you are considering surgery. You should never feel rushed to make a decision and I would be honored to help you find the right path for you!