What Is the CORI Robotic System?

If your surgeon has mentioned a "robotic" knee replacement, it is natural to picture a machine working on its own while everyone watches a screen. That is not what happens. The CORI system I use at Aster MIMS Kannur is better thought of as a very precise navigation tool that stays in the surgeon's hands the whole time. This guide explains, in plain language, exactly what it is and how a CORI procedure works step by step.

What CORI actually is

CORI is a robotics-assisted surgical system made by Smith+Nephew. Two features make it stand out, and both matter to you as a patient.

First, it is handheld. Rather than a large robotic arm, the working part is a compact tool the surgeon holds and controls directly. Second, it is image-free. Some robotic systems need a CT scan before surgery to build their plan. CORI does not. Instead, the surgeon collects the information the system needs during the operation itself, by mapping your real anatomy.

That combination is the heart of how CORI works, and it is why the experience leading up to your surgery is no different from a standard knee replacement: there is no extra scan to book, and no planning CT to sit through.

The image-free part: what it means for you

You will still have the usual X-rays and assessments that any knee replacement requires. What you avoid is the additional CT scan that some other robotic systems rely on.

How a CORI procedure works, step by step

Here is the sequence I follow in theatre. It is the same logical order I would use for any knee replacement, with the system adding precision at each stage.

At a glance: the CORI system

What the evidence really shows

The honest, well-proven benefit of robotic assistance is precision. When researchers pool the results of randomised trials comparing robotic-assisted and conventional knee replacement, the robotic group consistently has fewer alignment outliers, meaning fewer knees that end up further from the planned position. In one systematic review of randomised trials, robotic assistance reduced the risk of mechanical-alignment outliers substantially compared with conventional instruments.

It is just as important to be clear about what the evidence does not yet show. In the first few years after surgery, pain scores, function and patient satisfaction tend to be broadly similar between robotic and manual surgery, and complication and revision rates are comparable. Robotic surgery also tends to take a little longer in theatre. So the fair summary is this: the proven edge is accuracy and consistency, not a guaranteed better-feeling knee.

How CORI compares with other robots

You may have read about the Mako system, which is also used for knee replacement. The main difference is design, not a contest. CORI is handheld and image-free, mapping your bone during surgery. Mako is a robotic arm that uses a pre-operative CT scan to build its plan. Both share the same goal of precise, patient-specific implant positioning, and there is no robust evidence that one robotic system produces better patient outcomes than another. The choice usually reflects the implant system and what the hospital and surgeon use.

Having CORI robotic knee replacement in Kannur

I am Dr. Vishnu Baburaj, consultant orthopaedic surgeon at Aster MIMS Hospital, Kannur, with an M.S. in Orthopaedics from PGIMER Chandigarh and MRCS from the UK. I use the Smith+Nephew CORI system for suitable patients across North Kerala and Malabar, including those travelling from Thalassery, Payyannur, Taliparamba, Mattannur and Iritty.

If you want to understand whether robotic assistance is right for your knee, the best starting point is a proper assessment. You can read more on our robotic knee replacement page, see how it fits within knee replacement surgery overall, or go deeper with our detailed guide to robotic knee replacement. When you are ready, you can request an appointment or a second opinion through the clinic.