Robotic Knee Replacement: How Does It Work and Is It Right for You?
In robotic knee replacement, a computer-guided robotic arm helps the surgeon place the knee implant with greater precision. The surgeon stays in full control from start to finish. Better implant placement can mean more comfort, a knee that feels more natural and a smoother recovery than with traditional surgery.
Key points
- The surgeon controls the robotic arm at all times. The robot does not operate on its own.
- Precise implant placement may reduce pain and improve how the knee feels after surgery.
- Scans before the operation are essential. Standing, weight-bearing scans show alignment that lying-down scans can miss.
- Robotic-assisted surgery is not suitable for everyone. Your surgeon will advise you based on your own situation.
- ScanAlign provides diagnostic imaging only. We do not provide surgery or treatment.
What is robotic knee replacement and how does it work?
Robotic knee replacement is a type of joint surgery. The surgeon uses a robotic arm, guided by a 3D computer model of your knee, to remove damaged bone and cartilage and to place the implant. The robot does not make decisions or move by itself. Your surgeon guides every cut.
Before the operation, your knee is scanned to build a detailed digital plan. During surgery, the robotic arm follows that plan and gives live feedback. If the surgeon needs to make a change, they can do so at any point. The system works as a very precise tool, much like power steering helps a driver without taking the wheel.
Several robotic systems are used in the UK, including Mako, ROSA and NAVIO. Each works a little differently, but the idea is the same: the surgeon leads, and the robot assists.
Is robotic knee replacement better than traditional surgery?
Research suggests robotic-assisted knee replacement can offer advantages over traditional (manual) surgery. Results depend on many factors, though, including the surgeon's experience and the quality of the plan made before the operation.
The robotic arm helps place the implant within tighter limits than manual cutting alone.
Better alignment may mean the knee bends and moves more naturally after recovery.
Precise bone preparation may reduce unnecessary tissue damage during the operation.
Some patients say they got back to daily activities sooner, but this varies from person to person.
Keep in mind that robotic knee replacement is still surgery. It has the same general risks as any knee replacement, including infection, blood clots and stiffness. Your orthopaedic surgeon is the right person to talk to about whether a robotic-assisted approach suits your case.
Why do scans before surgery matter for robotic knee replacement?
The accuracy of robotic knee replacement depends entirely on the quality of the plan made before the operation, and that plan starts with scans. The better the images, the better the digital model, and the more precisely the surgeon can place the implant.
Most scans before surgery are done lying down on a CT or MRI table. This relaxes your muscles and takes the forces of gravity and body weight off your joints. The result is a picture of your knee in a position you never really use. When you stand, your alignment changes. Weight shifts, joints press together and any tilt in the hip or ankle can change how the knee sits.
Standing, weight-bearing EOS imaging captures your whole skeleton from head to foot in a natural, upright position. This means your surgeon can see exactly how your knee lines up with your hip, ankle and spine under real load. It shows compensations and imbalances that disappear when you lie flat.
EOS also uses about 90% less radiation than a standard X-ray, around ten times less. So you get a detailed, full-body picture at a very low dose.
Lying-down scans (CT and standard X-ray) show excellent bone detail, but they miss the effect of gravity and weight on alignment. A knee that looks straight when you lie flat may tilt inward or outward when you stand. If the surgical plan is based only on lying-down images, the implant position may not match your alignment in daily life.
Your body works as a connected chain. A tilt in the pelvis can shift load through the hip and into the knee. A flat foot can rotate the shin bone. These knock-on effects only show when you are standing. That is why surgeons planning robotic knee replacement increasingly value standing, whole-body alignment data.
At ScanAlign in London, we provide standing EOS imaging that shows your full alignment from head to foot. This data can form part of the planning before robotic-assisted knee surgery.
Book a free video consultationWhen is MRI the better choice? EOS is excellent at showing bones, joints and mechanical alignment. For soft tissue, cartilage damage, ligament tears or nerve problems, MRI is usually the better tool. Many patients benefit from both types of scan before knee surgery.
Who is a good candidate for robotic knee replacement?
Robotic-assisted knee replacement may be suitable if you have significant knee arthritis that has not improved with other management, and your surgeon recommends joint replacement. It is not limited to one type of patient, but it is not right for everyone either.
- You have end-stage arthritis in one or both knees
- Non-surgical treatments have not given enough relief
- You want the most precise implant placement available
- You have alignment problems in the hip, knee or ankle chain
- Your knee pain has a soft-tissue cause (ligament or meniscus) that does not need a replacement
- You have an active infection in or around the knee
- Your surgeon advises a different approach for clinical reasons
- You have certain complex deformities that fall outside the robotic system's range
Only your orthopaedic surgeon can decide whether robotic-assisted surgery is right for you. ScanAlign does not give surgical opinions. We provide the diagnostic imaging that helps your surgical team make the best plan.
Before you start treatment, or change the one you are on, it is worth getting a detailed diagnosis. Knowing whether the cause sits in the pelvis, the legs or the spine changes what will actually help.
If you have sudden weakness, numbness, loss of bladder or bowel control, or severe swelling with fever, please get urgent medical help from your doctor or your nearest emergency department rather than booking a scan.
Frequently asked questions about robotic knee replacement
No. The surgeon is in complete control at all times. The robotic arm acts as a precision tool that follows the surgeon's plan made before the operation. The surgeon can override or adjust the system at any point during the operation.
Robotic-assisted surgery carries the same general risks as traditional knee replacement, including infection and blood clots. The possible advantage is greater precision in implant placement, which may improve long-term results. Your surgeon can discuss the specific risks and benefits for your case.
Recovery varies from person to person. Some patients say they returned to light daily activities within a few weeks, with a fuller recovery taking several months. Your surgical team will give you a timeline based on your health and the details of your operation.
When you lie down for a CT or standard X-ray, gravity is removed and your muscles relax. This can hide alignment problems that only appear when you stand and bear weight. Standing EOS imaging shows your true weight-bearing alignment from head to foot. This gives the surgical team a more accurate picture for planning.
An EOS scan takes a full-body image while you stand upright. It captures your whole skeleton in one pass, showing how your joints line up under real load. It uses about 90% less radiation than a standard X-ray, around ten times less. You can learn more on our EOS scan overview page.
No. You can book directly without a referral. We offer a free video consultation to discuss whether a standing EOS scan is right for your situation before you book.
The price for patients travelling from abroad is confirmed during the free video consultation, and you can read more on our FAQs and cost page.
Yes. The EOS system uses about 90% less radiation than a standard X-ray, around ten times less. It is a very low-dose imaging method. More information about safety is on our FAQs page.
EOS gives different information from CT. It is excellent at showing full-body weight-bearing alignment, which CT cannot capture. Many robotic systems use CT for their 3D bone model, so your surgeon may recommend both. EOS adds a layer of alignment data that CT alone does not provide.
No. ScanAlign is a diagnostic imaging clinic. We provide the scans and alignment assessment that can help your orthopaedic surgeon plan your operation. We do not perform surgery or provide treatment.
Thinking about robotic knee replacement?
Find out whether standing whole-body imaging could improve your surgical plan. Our free video consultation takes a few minutes and carries no obligation.
Book a free video consultationWant to know more about knee alignment? Visit our knee imaging page.
Sources
- Kayani B, Konan S, Tahmassebi J, Pietrzak JRT, Haddad FS. "Robotic-arm assisted total knee arthroplasty is associated with improved early functional recovery and reduced time to hospital discharge compared with conventional jig-based total knee arthroplasty." The Bone & Joint Journal, 2018;100-B(7):930-937.
- National Joint Registry (NJR). Annual reports on knee replacement outcomes in England, Wales, Northern Ireland and the Isle of Man. njrcentre.org.uk
- NHS. "Knee replacement: overview." nhs.uk/conditions/knee-replacement
Written by Abbas Dhami (Specialist Diagnostic Radiographer)
This page is general information and not a diagnosis.
ScanAlign is the trading name of CoreMed Solutions Ltd and operates under The Harley Street Hospital's CQC licence.