Robotic knee replacement in Adelaide — how MAKO technology works and who it suits

Robotic-assisted knee replacement has become one of the most significant advances in joint replacement surgery over the past decade. In Adelaide, the technology is available through Dr Luke Mooney at Eastwood Private Hospital and Calvary Adelaide Hospital, using the Stryker MAKO robotic system.

This article explains how robotic knee replacement works, what it does differently from conventional surgery, what the evidence shows about outcomes, and whether it might be appropriate for your situation.

What is robotic knee replacement?

Robotic-assisted knee replacement is not a fully automated procedure — the robot does not operate independently. Rather, it is a precision guidance and feedback system that works alongside the surgeon during the operation, providing real-time data and enforcing pre-planned boundaries that improve the accuracy of implant placement.

The MAKO system, made by Stryker, is the most widely used robotic platform for knee replacement in Australia. It is used for both total knee replacement and partial (unicompartmental) knee replacement.

The two key components: pre-operative planning and intraoperative guidance

Before surgery, a CT scan of the knee is taken. The MAKO system uses this scan to build a detailed three-dimensional model of the patient’s individual anatomy — not a generic template, but a model specific to that patient’s bone shape, alignment, and joint geometry.

Using this model, the surgeon plans the operation in detail before entering the operating theatre: the precise size and positioning of each implant component, the target alignment, and the planned range of motion after surgery. This planning stage is a significant departure from conventional technique, where critical sizing and positioning decisions are made primarily during the operation itself.

During surgery, the robotic arm — controlled by the surgeon — provides real-time tactile feedback and operates within pre-programmed boundaries based on the plan. If the surgical tool moves outside the planned zone, the system resists movement, preventing unintended bone removal. Throughout the procedure, the system continuously verifies implant position against the pre-operative plan, allowing the surgeon to make adjustments in real time and confirm that positioning matches the target before finalising each step.

The surgeon is always in control. The robotic arm does not move autonomously — it is a precision tool that the surgeon directs. The boundaries it enforces exist to protect against inadvertent deviation from the surgical plan, not to replace surgical judgement.

Why does implant positioning matter so much?

The long-term outcomes of knee replacement — durability, function, and patient satisfaction — are strongly influenced by how accurately the implant is positioned. Alignment affects how load is distributed across the joint, how the knee tracks through its range of motion, and how much stress is placed on the implant–bone interface over time.

Studies comparing conventional and robotic-assisted techniques consistently show that robotic-assisted surgery produces implant positioning that is more accurate and more reproducible — meaning that implants end up where they were planned to be, with less variation between patients and between surgeons.

For patients, this translates to: more consistent restoration of the natural joint line and mechanical axis of the leg; reduced risk of early loosening from malalignment; potentially improved implant longevity over the medium and long term; and better matching of the implant to the patient’s individual anatomy rather than a population average.

What does the evidence show?

The evidence base for robotic-assisted knee replacement has grown substantially over the past ten years. Robotic-assisted surgery consistently produces smaller deviations from planned implant position compared with conventional technique. Several studies have also reported higher patient-reported satisfaction scores with robotic-assisted knee replacement, particularly relating to the feeling that the knee moves naturally — thought to relate to more individualised gap balancing and soft tissue management during the procedure.

Registry data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) is beginning to show favourable revision rates for robotic-assisted procedures. The most compelling reason to use robotic assistance is not the technology itself — it is what that technology makes possible: a level of pre-operative planning and intraoperative accuracy that is genuinely difficult to replicate consistently with conventional instruments alone.

Total knee replacement versus partial knee replacement

Robotic-assisted technique is well suited to both total and partial (unicompartmental) knee replacement.

Total knee replacement replaces all three compartments of the knee — the inner (medial) side, outer (lateral) side, and the kneecap groove. It is appropriate when arthritis is widespread across the joint. Robotic assistance is particularly valuable here because precise restoration of alignment and gap balance across the full joint is complex, and even small deviations have cumulative effects on function and longevity.

Partial knee replacement replaces only the affected compartment of the knee, preserving the remaining healthy cartilage and ligaments. When indicated, partial knee replacement typically results in a more natural-feeling knee than total replacement. Accurate component positioning is critical to its success, and robotic guidance is well validated in this application.

Who is a candidate for robotic knee replacement in Adelaide?

Robotic-assisted knee replacement is available to patients who have knee arthritis that is sufficiently advanced to warrant surgical treatment, who are medically fit for surgery, and who are admitted as private patients at Eastwood Private Hospital or Calvary Adelaide Hospital.

There is no upper or lower age limit that makes robotic technique specifically more or less suitable. The indication for surgery — and the decision about whether partial or total replacement is appropriate — is based on the degree and distribution of arthritis, the patient’s symptoms and functional goals, and the anatomy seen on imaging.

The CT scan required for pre-operative MAKO planning is arranged as part of the surgical workup. It involves a low-dose scan of the hip, knee, and ankle, and is typically straightforward to organise through a local radiology provider in Adelaide.

What to expect at a consultation

At a first consultation for knee pain or knee arthritis, Dr Mooney will assess the knee clinically and review standing X-rays. If surgical planning is being considered, the conversation will include whether partial or total replacement is appropriate, whether robotic-assisted technique is planned, and what the recovery process involves.

Not every patient who presents with knee pain requires surgery, and the consultation is as likely to confirm that non-surgical management remains appropriate as to recommend a surgical pathway. The aim of the consultation is to provide accurate information about what is happening in the knee and what the realistic options are, so that any decision is made with a clear understanding of the evidence.

Where is robotic knee replacement performed in Adelaide?

Dr Mooney performs robotic-assisted knee replacement using the MAKO system at Eastwood Private Hospital (204 Greenhill Road, Eastwood SA 5063) and Calvary Adelaide Hospital (120 Angas Street, Adelaide SA 5000). Both hospitals have the MAKO system available and experienced robotic-assisted theatre teams. A GP referral to Orthopaedics 360 is the starting point for assessment.