Robotic and Navigated Knee Replacement
Patient information — Dr Christopher Spelman, Orthopaedic Surgeon
Overview
Robotic-assisted and computer-navigated knee replacement use technology to help plan and execute the bone cuts and implant positioning. A CT or intraoperative map of your knee is used to build a plan, and the system guides the surgeon in carrying it out.
The surgeon performs the operation. The robot does not operate independently. It constrains and guides the cuts to match the plan.
Dr Spelman performs both navigated and robotic knee replacement, and will discuss whether either is appropriate for you.
What the evidence shows
Robotic knee replacement is heavily marketed, so it is worth separating what has been demonstrated from what has been claimed.
Alignment accuracy is better. This is consistent and well established. A systematic review of 12 randomised trials involving 2,200 patients found robotic-assisted surgery produced significantly fewer mechanical alignment outliers and less deviation from neutral alignment (Ruangsomboon et al., 2023). A meta-analysis of seven randomised trials covering 1,942 knees found the same (Alrajeb et al., 2024).
Whether patients can feel the difference is another matter. The same high-quality review found robotic surgery “probably results in little to no effect” on patient-reported outcomes or range of motion, and concluded the radiological advantage “may not be clinically meaningful” (Ruangsomboon et al., 2023).
A trial sequential meta-analysis of 25 randomised trials including 3,156 patients reached a similar conclusion: the only statistically significant clinical difference was that robotic surgery took longer — around 22 minutes on average. Knee Society Scores, WOMAC and Hospital for Special Surgery scores were comparable (Yue et al., 2025).
One meta-analysis of nine randomised trials did find a small statistically significant WOMAC advantage for robotic surgery, alongside slightly better long-term flexion in the conventional group (Daoub et al., 2024). The differences are small in both directions.
The findings are statistically fragile. A fragility analysis of randomised trials in this area found that a median of only three patients changing outcome would be enough to reverse the statistical significance of a typical result — and in 23 of 38 outcomes examined, more patients were lost to follow-up than that (Zabat et al., 2024). In plain terms: the published differences rest on very few patients, and should be treated with caution.
Complication and revision rates are similar between the two (Ruangsomboon et al., 2023; Alrajeb et al., 2024).
The honest summary
Robotic knee replacement puts the implant in a more consistently accurate position according to large studies. That is real and reproducible.
Whether it makes your knee feel better, work better, or last longer has not been demonstrated. Follow-up in the existing trials is short, and the theory that better alignment yields better long-term survivorship is plausible but not yet proven — that question needs ten- to twenty-year registry data, which does not exist yet for current systems.
It also takes longer than a conventional total knee replacement and has a higher cost burden due to consumable material.
A well performed conventional total knee replacement will likely be no better in terms of clinical outcomes than a robotic total knee replacement for the average patient.
Dr Spelman’s view is that the technology is a useful tool rather than a decisive one, and that the surgeon, the implant and the patients specific needs matter more than the platform.
Risks
Robotic knee replacement carries the same risks as conventional knee replacement — infection, blood clots, stiffness, persistent pain, loosening, periprosthetic fracture and the need for revision — plus:
• Pin site complications. Tracking arrays are fixed to bone with pins. Pin site infection and, rarely, fracture through a pin site have been reported
• Longer operative and anaesthetic time
• Additional radiation where the system requires a pre-operative CT
• Conversion to conventional technique if the system fails intraoperatively
References
1. Ruangsomboon P, Ruangsomboon O, Pornrattanamaneewong C, Narkbunnam R, Chareancholvanich K. Clinical and radiological outcomes of robotic-assisted versus conventional total knee arthroplasty: a systematic review and meta-analysis of randomized controlled trials. Acta Orthop. 2023;94:60–79. DOI
2. Alrajeb R, Zarti M, Shuia Z, Alzobi O, Ahmed G, Elmhiregh A. Robotic-assisted versus conventional total knee arthroplasty: a systematic review and meta-analysis of randomized controlled trials. Eur J Orthop Surg Traumatol. 2024;34(3):1333–1343. DOI
3. Yue HY, et al. Does robotic-assisted total knee arthroplasty improve outcomes of adult osteoarthritis patients — a systematic review and trial sequential meta-analysis. Orthop Surg. 2025;17(6):1549–1560. DOI
4. Daoub A, Qayum K, Patel R, Selim A, Banerjee R. Robotic assisted versus conventional total knee arthroplasty: a systematic review and meta-analysis of randomised controlled trials. J Robot Surg. 2024;18(1):364. DOI
5. Zabat MA, Giakas AM, Hohmann AL, Lonner JH. Interpreting the current literature on outcomes of robotic-assisted versus conventional total knee arthroplasty using fragility analysis. J Arthroplasty. 2024;39(7):1882–1887. DOI