What does robotic knee replacement mean?

Despite what the name suggests, robotic knee replacement does not refer to surgery that is performed by a robot! Robotic knee replacement blends innovative technology and the carefully honed skills of the surgeon to perform complex surgeries. It is a tool that is used by the surgeon to plan your knee replacement.

The planning stage of the knee replacement may be considered the most important part of the surgery. Robotic technology combines precision data and the experienced decision-making of the surgeon for optimal results. Ultimately the surgeon’s expertise is a crucial element in surgical planning, and robotic technology alone would be unable to achieve the best results.

There are only few surgical companies which have ventured into robotic technology and it is the discretion of the surgeon to select the appropriate shape and functioning implant for you. It is possible to look up outcome date for different implants in the Australian National Joint Registry. Mr Unni performs robotic assisted knee replacement using the Zimmer ROSA Robot.

The process of robotic surgery

Firstly, the surgeon will request a special X-ray or CT scan of your knee. This can be used to generate 2D or 3D images and data. The surgeon will also do an examination of the knee and assess the surrounding tissue. The data from the scan results and information from the examination of your knee are then combined and used by the robotic technology to help to plan your surgery.

During the surgery, pins are placed on your leg, with special antennae attached, which are able to communicate with the robot. The knee is then re-evaluated during the surgery and the surgeon makes adjustments using this information to get the best fit of your implant to your knee. The robot then repositions its arms to allow the surgeon to make the most precise cuts. This allows the prosthesis to be implanted in the optimal position.

Mr Unni in theatre with Rosa Knee robotic technology

Current evidence

The Australian National Joint registry has observed that the precision of implant placement has marginally improved by using robotic technology. However, we are yet to notice whether this makes a difference to the patient in terms of their experience with their prosthetic knee.

What are additional risks and complications of robotic surgery

Compared with a standard knee replacement, infection risk is believed to be slightly increased due to the presence of an additional large machine being placed inside the operating theatre. However, this has not shown to be statistically significant.

Also because of insertion of pins on the thigh and leg bone, there is a theoretical risk of fracture, but once again this has not been shown to have any statistical significance.


Robotic knee replacement may not necessarily always achieve superior results with regards to early discharge, reduced pain, smaller incisions, or good functional movement. Surgical skill and experience is crucial.

Further information

ROSA Knee robotic technology