The VELYS™ Robotic-Assisted Solution has now been formally introduced at The Rivers Hospital and Mr Kosuge started performing robotic-assisted total knee replacements this week. It is a good moment to answer the question he is asked most often, which is a fair one. Is a robotic knee replacement better than a conventional one and is it the right choice for you? It is worth answering plainly, because the marketing around robotics can make the decision sound more dramatic than it is.

What "conventional" knee replacement actually means

A conventional total knee replacement is a very well-established operation with an excellent track record. The worn surfaces of the knee are removed and replaced with metal and plastic components and Mr Kosuge uses precise instruments, measurements and experience to position them. The great majority of these replacements perform well for many years. When people worry that "conventional" means old-fashioned, that is not the case. It remains the operation that the long-term registry data is built on.

What the robot adds

Robotic assistance does not replace the surgeon. Mr Kosuge remains in control of the operation throughout. What the system adds is a detailed plan and real-time feedback. Before and during surgery, it builds a picture of your individual knee. It then helps position the implant and balance the soft tissues to Mr Kosuge’s plan with a high degree of accuracy. In published work the VELYS system has been shown to place components within a few degrees of the intended alignment very consistently.

Does more precision mean a better result for you?

This is the honest part. Better alignment and balance are sensible goals and early studies have reported benefits such as improved mobility and shorter hospital stays. What has not yet been proven is that a robotic knee lasts longer than a well-performed conventional one over fifteen or twenty years, because that evidence will take longer to gather. So the fair summary is that robotic assistance is a genuine advance in accuracy and consistency, rather than a guarantee of a different outcome for every patient.

Who benefits most

Robotic assistance can be particularly useful where the anatomy is more challenging or where fine soft-tissue balancing matters. For many patients either approach in experienced hands will give an excellent result. The most important factor remains the surgeon and the whole team around the operation, not the tool alone.

Discussing your options

Mr Kosuge offers both conventional and VELYS robotic-assisted total knee replacement at The Rivers Hospital and will talk through which is more appropriate for your knee at consultation. You can review his published outcome data:

To book an appointment with Mr Kosuge at The Rivers Hospital:

• Online booking

• Telephone: 01279 602675

Mr Kosuge is pleased to announce that robotic-assisted total knee replacement using the VELYS™ Robotic-Assisted Solution will be available at The Rivers Hospital, Sawbridgeworth, from July 2026. This is a significant development for patients in Essex and Hertfordshire seeking the most advanced approach to knee replacement surgery — one that combines Mr Kosuge's surgical expertise with a technology designed to improve precision and personalise each procedure to the individual patient.

What Is the VELYS™ Robotic-Assisted Solution?

VELYS is a state-of-the-art surgical technology developed by DePuy Synthes, part of Johnson & Johnson MedTech — one of the world's leading orthopaedic companies. The system uses pre-operative planning and real-time intraoperative guidance to assist the surgeon in performing total knee replacement with exceptional accuracy.

Before surgery, a personalised plan is created based on each patient's individual anatomy. During the procedure, VELYS provides continuous real-time data and feedback, helping to ensure the implant is positioned precisely in line with that plan — adjusting dynamically for even the subtlest variations in the patient's anatomy as surgery progresses.

It is important to be clear about what VELYS is and is not. The robot does not operate independently. Mr Kosuge remains entirely in control throughout the procedure. VELYS acts as an advanced assistive tool — enhancing the precision with which the surgery is performed, not replacing the judgement or skill of the surgeon.

Why Precision Matters in Knee Replacement

The accuracy of implant positioning is one of the most consequential factors in knee replacement outcomes. When an implant is correctly aligned to a patient's anatomy and biomechanics, patients typically experience better function, less post-operative pain, and a more natural-feeling result in the replaced knee.

Traditional knee replacement uses mechanical guides and surgical expertise to achieve this alignment — and in experienced hands, outcomes are consistently excellent. VELYS adds a further layer of technological precision, providing objective real-time data to support the surgical plan and helping to ensure consistent accuracy throughout the procedure.

What the Evidence Shows

A peer-reviewed study published in 2025 found that VELYS robotic-assisted total knee replacement was associated with improved mobility, a reduction in hospital stay, shorter surgical duration, and better psychological outcomes compared to conventional approaches. Independent research has also demonstrated greater post-operative range of motion and reduced pain in patients who underwent robotic-assisted procedures.

In one study, all 101 cases achieved the target coronal plane alignment within 3 degrees — a measure of how accurately the implant is positioned in the knee. This level of consistency is a key aim of robotic-assisted surgery and an important contributor to long-term implant function.

Is Robotic-Assisted Surgery Right for You?

VELYS-assisted total knee replacement is suitable for the majority of patients requiring total knee replacement surgery. A consultation with Mr Kosuge will determine whether this approach is appropriate for your specific anatomy, the extent of your joint damage, and your overall health. Not every patient will be an ideal candidate for every technique — Mr Kosuge will always recommend the approach that is best suited to the individual.

For more information about VELYS robotic-assisted surgery.

Book a Consultation

If you are considering knee replacement surgery and would like to discuss whether VELYS-assisted surgery is the right option for you, Mr Kosuge is happy to talk through your situation in detail at an initial consultation. Appointments are available at The Rivers Hospital, Sawbridgeworth — with VELYS robotic-assisted surgery available from July 2026.

• Online booking

• Telephone: 01279 602675