More and more patients undergoing a total knee replacement are opting for robotic arm-assisted surgery. In this article, we’ll look at what this entails and consider a recent study, published in the Bone Joint Journal, which explored whether this type of surgery makes a difference to outcomes when compared with conventional total knee replacements.
What is robotic arm-assisted total knee replacement surgery?
A total knee replacement is used to treat severe knee pain caused by osteoarthritis or a serious fracture. It involves removing the damaged knee joint and replacing it with a prosthetic implant. In a total knee replacement, the entire joint is replaced, whereas a partial knee replacement involves replacing only one section of the knee joint.
Some orthopaedic surgeons are now using the Mako SmartRobotics system to support them with joint replacement surgery. Prior to surgery, a CT scan of the affected joint is uploaded to the Mako system. This then generates a detailed pre-operative plan based on the patient’s unique anatomy. This shows precisely how much bone needs to be removed and helps the surgeon to align the implant with greater accuracy. Once on the operating table, a robotic arm helps to guide the surgeon to remain within the limits of this surgical plan, ensuring that only diseased bone is removed and healthy bone is left intact. Auditory and visual feedback from the robotic arm lets them know the optimum orientation to ensure maximum stability and mobility of the replacement joint.
One of the primary benefits of robotic arm-assisted surgery is increased accuracy. This results in less pain, which can occur if an implant is not correctly aligned, and fewer complications after surgery. There is less strain on soft tissues and ligaments and a lower chance of implant failure.
Newcastle team’s randomised controlled trial
A research team from Freeman Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust recently conducted a 12-month randomised controlled trial to assess whether robotic arm-assisted total knee replacements achieve better outcomes than conventional total knee replacement surgery.
Methodology
Between May 2019 and December 2021, the team looked at 100 randomised patients – 50 of whom underwent a robotic arm-assisted total knee replacement and 50 of whom underwent conventional total knee replacement surgery. There were no statistically significant preoperative differences between the groups. The minimal clinically important difference in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score was defined as 7.5 points.
Findings
After 12 months, there were no significant differences between the two groups using knee-specific measures (WOMAC, Oxford Knee Score, Forgotten Joint Score or HRQoL). However, the group that underwent robotic arm-assisted surgery showed significantly greater improvement in the WOMAC pain score post-operatively (at two, six and 12 months) compared to the group that had conventional surgery. The mean difference was 9.7%, 95% confidence interval 1.0 to 18.4. The robotic arm-assisted group was also more likely to expect relief of pain in the joint during the daytime, and for this expectation to be fulfilled. There was no significant difference between the two groups in relation to knee function or health-related quality of life (HRQoL) measures.
Robotic arm-assisted surgery linked to lower pain
What this research shows is that having a robotic arm-assisted total knee replacement is likely to result in a greater reduction in knee pain compared to having a conventional total knee replacement. During the daytime, there is also likely to be less joint pain. There is no particular difference in knee function or quality of life when comparing these two surgical approaches.
Find out more about Robotic Joint Replacement
If you would like more information about a total knee replacement or to find out more about the difference between conventional knee replacement surgery and robotic arm-assisted surgery please contact us.
