Robot-Assisted Knee Replacement Offers No Better Outcomes compared to conventional surgery: Study
A new study published in the journal of The Lancet showed that the results of individuals undergoing knee replacement surgery were comparable whether robotic assistance or traditional surgery was used.
Over 3 million knee replacements were performed in 2023 because of osteoarthritis in the knee, a significant source of disability worldwide. While the majority of patients get significant improvement, 12–20% still have severe pain or discontent. Globally, robotically assisted total knee replacement (TKR) is becoming more and more popular. It may improve surgical accuracy, limit tissue damage, and lessen early postoperative discomfort.
3-dimensional surgical planning and controlled bone cuts are made possible by CT-based technologies like Mako, which enable implant location customized to each patient's anatomy. Nevertheless, compared to traditional equipment, robotic systems are more costly and could take longer to operate. Therefore, this study determined the Mako robotic-arm system's clinical efficacy and cost-effectiveness in comparison to traditional TKR devices.
This pragmatic, superiority, randomized controlled study had 33 surgeons at 10 institutions in Great Britain. TKR was performed on patients with advanced knee osteoarthritis using either the Mako robotic-arm-assisted system (rTKR) or conventional tools (cTKR). Inflammatory arthropathy, prior fractures, or the requirement for complicated implants were important exclusion factors.
Using minimization by age, BMI, center, surgeon, and principal knee compartment affected, participants were assigned at random (1:1) via a remote computer system. Sham incisions, extra draping, and masked operation notes were some of the techniques used to conceal participants and assessors. Using a linear mixed-effects model and the intention-to-treat principle, the main outcome was the Forgotten Joint Score (FJS) at 12 months following randomization. 12 points was the predetermined target differential.
807 individuals were tested between December 21, 2021, and December 13, 2023, and 339 of them were randomly assigned: 168 to rTKR and 171 to cTKR. There were 167 (49%) females and 172 (51%) males, with a median age of 68·8 years (IQR 61·3–75·2).
The mean FJS at 12 months was 50·2 (29·9; n=158) in the cTKR group and 49·2 (SD 28·4; n=154) in the rTKR group. 16 individuals in each group experienced one major adverse event; the adjusted mean difference was –1·5 (95% CI –7·5 to 4·5; p=0·62), favoring cTKR.
Overall, this study comparing rTKR and cTKR recommended no specific alignment technique. Up to 12 months after randomization, rTKR did not offer patients a clinically significant advantage and was more expensive than cTKR when utilized in this experiment.
Source:
Parsons, H., Metcalfe, A., Griffin, J., Khatri, C., Bradley, H., Blyth, M., Clement, N., Croft, N., Deehan, D., Ellard, D., Frempong, S., Grant, N., Haddad, F., Hutchinson, C., Mason, J., Mistry, H., Naghdi, S., Scott, C., Smith, T., … RACER-Knee trial team. (2026). Robotic-arm-assisted versus conventional total knee replacement (RACER-Knee): a pragmatic, multicentre, participant-masked and assessor-masked, superiority, randomised controlled trial. Lancet. https://doi.org/10.1016/S0140-6736(26)00986-4
