Robotic-Assisted Knee Replacement: What It Actually Means for You as a Patient

If you have been researching knee replacement lately, you have probably come across the word “robotic” more than once. It is easy to picture something out of science fiction — a machine making decisions on its own while you are asleep on the table.

That is not what happens. In a robotic-assisted knee replacement, the surgeon performs the operation and makes every decision. The robotic system carries out a plan the surgeon built beforehand, and provides real-time feedback to help place the implant where it was planned. Understanding that distinction is the difference between being unsettled by the technology and being able to ask useful questions about it.

Robotic assistance has quickly become one of the most talked-about advances in orthopaedic surgery. In April 2026, a California health network announced that one of its surgeons had reached 1,000 knee replacements using the TMINI handheld robotic system, a milestone its headline described as a world record, and Mayo Clinic has described the shift toward robotic and personalised techniques as the start of a new era for joint surgery. For patients, headlines like these tend to raise as many questions as they answer.

So here is what the technology actually does, and what it might mean for your own knee.

The robot doesn’t perform your surgery — your surgeon does

This is the point worth clearing up first. Robotic-assisted knee replacement is exactly that: assisted. Your surgeon is the one making every decision and every cut. The robotic system is a highly precise tool that helps carry out the surgical plan your surgeon has already mapped out — a bit like a GPS supports a driver who is still the one steering the car.

The system does not act independently, does not make clinical judgements, and is never left to its own devices. It holds the plan and helps execute it accurately.

How the planning works: a virtual pre-operation

Before your operation, imaging of your knee may be used to build a detailed three-dimensional model of the joint. On the Mako system, which Dr Clark uses, this means an additional CT scan taken specifically for planning. (He also uses VELYS, which builds its model in theatre instead and needs no scan.)

That model lets your surgeon plan implant size, positioning and alignment in detail, tailored to your own anatomy rather than a generic template. The operation is effectively rehearsed on a computer first — a virtual pre-operation. It is a starting plan rather than a final one: in theatre the knee is matched to the model, the ligaments and soft tissues are assessed, and the plan is adjusted where needed.

During surgery, the robotic arm or handheld device provides real-time feedback, helping your surgeon place the implant where it was planned and fine-tune the balance of the surrounding soft tissue. If something in the knee turns out differently once the joint is opened, the plan can be adjusted then and there.

Why precision matters more than it sounds

It is tempting to think a knee replacement is a knee replacement. But small differences in alignment and implant fit have a real effect on how a new knee feels day to day.

A joint that is even slightly out of balance can lead to:

• Stiffness, or a knee that never quite feels like it settles
• An unnatural feeling through the gait
• Uneven loading, and faster wear over time

The appeal of robotic assistance is that it narrows the margin for error and allows a more personalised fit, accounting for your particular bone shape, ligament tension and range of motion. Studies show more predictable alignment. Whether patients notice a more natural-feeling knee as a result is less certain.

What the evidence does and doesn’t show

It is worth being straight about this, because the marketing around robotics tends to run ahead of the data.

What is well established: robotic assistance improves the accuracy of implant positioning and limb alignment. Surgeons hit their intended targets more consistently, with fewer outliers.

What is still being measured: whether that accuracy means implants last longer. Answering that properly takes 15 to 20 years of follow-up, and the technology has not been in widespread use long enough. The Australian Orthopaedic Association National Joint Replacement Registry tracks every joint replacement performed in Australia and is monitoring robotic-assisted procedures specifically. Early signals are encouraging, but they are early.

As with any surgery, the result still depends heavily on the surgeon’s skill and experience, and on you — your general health, your commitment to rehabilitation, and the condition of the joint going in. Technology narrows the margin for error. It does not replace judgement, and it does not do your physiotherapy for you.

Is robotic-assisted knee replacement right for you?

If you are a suitable candidate for a conventional knee replacement, you are generally also a candidate for a robotic-assisted one. It is not reserved for particularly complex or unusual cases, though it can be especially useful where the anatomy is more challenging to work with — significant deformity, unusual bone shape, or a previous injury that has changed the alignment of the leg.

Robotic assistance is used for both total knee replacement and partial knee replacement. In a partial replacement, where only the damaged compartment of the knee is resurfaced, accurate positioning matters a great deal — there is less room for error when the rest of the joint is being preserved.

The right question to bring to your consultation is not “should I ask for the robot,” but “what approach do you recommend for my knee, and why?” A good surgeon will explain their reasoning, whether or not that includes robotic assistance, and will be honest with you about what to expect. Technology is one part of a good outcome. The experience and judgement of the person operating on your knee still matters most.

If you’re considering knee surgery in Perth

Dr Rhys Clark uses robotic assistance for both total and partial knee replacement, with the Mako system (planned as a virtual pre-operation from a CT scan) or the imageless VELYS system. He consults at St John of God Medical Clinic in Murdoch and in Mandurah, and operates at St John of God Murdoch, with public lists at Sir Charles Gairdner Hospital.

For the detail — how the CT planning works, what the evidence supports, who it suits and what it costs — see robotic-assisted knee replacement.

If you are earlier in the process and still working out whether surgery is the right step, Understanding Knee Arthritis covers what arthritis is and what the non-surgical options look like. If cost is on your mind, what a knee replacement costs in Australia sets out the public, private and self-funded pathways — Dr Clark works on a no-gap basis for privately insured patients.

The takeaway

Robotic-assisted knee replacement is not about handing your surgery over to a machine. It is about giving your surgeon a more precise set of tools to plan and carry out an operation tailored specifically to your knee.

If you are weighing up your options, it is a reasonable thing to ask about at your next appointment — alongside all the other questions that matter just as much: your surgeon’s experience, your own health and goals, and what your recovery will realistically look like.

If you would like to talk through whether knee replacement, robotic-assisted or otherwise, is the right next step for you, book a consultation and we can discuss what suits your knee and your lifestyle.