Robotic knee replacement uses a computer-guided robotic arm to help your surgeon plan the operation and make the bone cuts to that plan. Your surgeon still performs the operation. The robot works within boundaries that are set before surgery.
Robotic assistance can position the implant more accurately than conventional instruments. Whether that accuracy leads to better long-term results is still being studied. Early registry data are encouraging for partial knee replacement, but long-term results for robotic total knee replacement are not yet available.
To see how Dr Vishal Pai uses the robot, read about robotic knee replacement in Melbourne.
At a Glance
- Robotic assistance helps your surgeon plan implant size and position from a 3D model of your knee, then make the bone cuts to that plan.
- It can position the implant more accurately than conventional instruments.
- Early Australian registry data showed a lower revision rate for robotic partial knee replacement at three years.
- There are not yet long-term data showing better function or implant survival after robotic total knee replacement.
- Patient selection, surgical technique and rehabilitation matter as much as the technology.
Why does accuracy matter in knee replacement?
Total knee replacement is designed to relieve pain from knee arthritis, and most people are satisfied with the result. Even so, studies have reported that about one in ten people are not satisfied after a total knee replacement. Surgical techniques and implants continue to be refined to improve this.
A conventional knee replacement uses metal guides, called jigs, to direct the bone cuts. The jigs are positioned using landmarks within your knee. Even in experienced hands, there is some variation in the final position of the implant.
Computer navigation was designed to reduce this variation. Trackers attached to your leg send information to a computer, which helps your surgeon place the jigs more accurately. Data from the Australian Orthopaedic Association National Joint Replacement Registry showed a lower revision rate in patients younger than 65 whose knee replacement was performed with computer navigation.
Patient-specific jigs are another option. Scans of your knee are used to build a virtual model, and custom jigs are made to fit it. The implant itself is not custom-made, and occasionally the jigs do not fit your knee accurately during surgery. In that case your surgeon may need to switch to a conventional technique.
How is a robotic knee replacement performed?
Robotic-assisted knee replacement builds on computer navigation. The main steps are:
- Scans of your knee are used to create a virtual model.
- The model is used to plan the size and position of the implant.
- During the operation, landmarks within your knee are used to check the plan before any bone is cut.
- Your surgeon makes the bone cuts with the robotic arm, which keeps the saw within the planned boundaries.
- Your surgeon then checks how the knee moves and how tight the ligaments are through its range of motion, and can fine-tune the bone cuts or soft-tissue releases to balance the knee.
Is robotic knee replacement more accurate?
Robotic-assisted knee replacement positions the implant more accurately than conventional instruments. The robotic arm allows your surgeon to carry out the pre-operative plan closely.
Accuracy is a technical measure, though. On its own, it does not mean that your knee will feel better or that the implant will last longer.
Does robotic assistance improve the results of knee replacement?
For total knee replacement, there are not yet long-term data showing better function or longer implant survival with robotic assistance.
For partial knee replacement, early data from the Australian Orthopaedic Association National Joint Replacement Registry showed a lower revision rate for robotic-assisted procedures at three years of follow-up.
Partial knee replacement requires training and experience to perform well, and surgeons who perform it regularly tend to have better results. The margin for error in implant position is smaller in a partial knee replacement, which may explain why robotic assistance appears to help.
Dr Vishal Pai uses Mako robotic assistance with the fixed-bearing Stryker Restoris MCK implant for partial knee replacement. You can read more in Partial or Total Knee Replacement: Which Is Right for You?
Is robotic knee replacement right for you?
Robotic assistance is one part of a successful knee replacement. Other factors include appropriate patient selection, pre-operative planning, surgical approach and technique, pain management after surgery and rehabilitation.
Robotic assistance may be most useful for people with complex knee problems and for younger people, but the long-term results are yet to be determined.
Knee replacement is usually considered only after non-surgical options, such as exercise, physiotherapy, weight management and pain relief, have not helped enough. You can read about these in Non-surgical options for knee osteoarthritis.
Robotic surgery carries the same risks as any knee replacement, including infection, blood clots, stiffness, persistent pain and the possibility of further surgery.
Summary
Robotic knee replacement helps your surgeon plan and carry out the operation accurately. Early registry data for robotic partial knee replacement are promising, but long-term benefits for robotic total knee replacement have not yet been shown. The right operation for you depends on your arthritis pattern, symptoms and general health.
If you would like to discuss how this applies to your knee, you can book a consultation with Dr Vishal Pai.
Find out whether robotic knee replacement may suit you
Dr Vishal Pai assesses knee arthritis and performs robotic partial and total knee replacement. You can arrange a consultation to discuss your symptoms, imaging and treatment options.
Written by Dr Vishal Pai
Vishal is an experienced knee surgeon based in Bayside, Melbourne. He consults at Sandringham Orthopaedic Specialists and operates at The Avenue Hospital and Calvary Holmesglen Private Hospital. His practice focuses on sports knee surgery, including ACL reconstruction and meniscal repair, as well as robotic knee replacement.