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All topics
  1. What it is
  2. Who it helps
  3. Timing
  4. The procedure
  5. Patient journey
  6. Recovery supplies
  7. Implant designs
  8. Side-by-side
  9. Robotics and alignment
  10. US manufacturers
  11. What the evidence says
  12. Value analysis
  13. Questions to ask
  14. Resources
  15. Glossary
  16. References

Technology

Robotics, navigation and alignment

In a robotic-assisted knee replacement, the surgeon still does the operation. The robot helps plan and guide the bone cuts to match a plan, usually built from a CT scan or from mapping the knee during surgery. Navigation and augmented-reality systems do something similar without a robotic arm.

Robotic use is growing fast: in US commercial claims it rose from about 8% of knee replacements in 2016 to 25% in 2022.17

What the research shows

  • More precise cuts. Robotic surgery produces fewer knees outside the planned alignment and somewhat less blood loss, with longer operating time.23
  • No clear difference for patients yet. A 2026 meta-analysis limited to randomized trials found no difference in pain, function, satisfaction or hospital stay.22
  • Long-term data are still coming. Whether better precision means longer-lasting knees hasn't been shown yet.

Alignment: mechanical or kinematic

Traditionally surgeons aimed for a straight "mechanical" alignment for every patient. Newer approaches, such as kinematic alignment, try to recreate each person's natural knee angles. Randomized trials so far show similar results between these approaches.24,25

Robotic systems in the US include Stryker's Mako, Zimmer Biomet's ROSA, J&J MedTech's VELYS, Smith+Nephew's CORI, Globus Medical's ExcelsiusFlex, Corin's Apollo and THINK Surgical's TMINI. See US manufacturers.

Clinical detail
  • 24 RCTs (3,425 patients): no difference in WOMAC function, KSS, OKS, pain, satisfaction or length of stay; operative time 22.34 minutes longer; low to very low certainty.22
  • 11 RCTs of kinematic vs mechanical alignment (972 patients): no difference in reoperation (RR 1.34) or PROMs; in bilateral studies patients preferred the kinematically aligned knee (RR 2.15).24 A network meta-analysis of 22 RCTs found no clinically meaningful difference among five alignment philosophies.25
Value analysis

Robotic platforms involve capital or placement agreements, disposables, imaging and set-up time. A systematic review found most health-economic studies of CT-based robotic-arm arthroplasty reported lower 90-day episode costs, but it had a manufacturer co-author, so weigh it accordingly.43 Ask vendors for implant-agnostic data and for your own utilization and episode-cost tracking.

Sources for this page

  1. Finch D, et al. National trends in use and complications of cemented, cementless, manual, and robotic-assisted total knee arthroplasty: 2016-2022. J Knee Surg. 2026;39(4):208-217. doi:10.1055/a-2712-4129
  2. Abdelaziz O, et al. Comparative pain relief and functional outcomes following robotic-assisted versus conventional total knee arthroplasty: a GRADE-assessed meta-analysis with meta-regression of randomized controlled trials. J Robot Surg. 2026;20(1). doi:10.1007/s11701-026-03934-0
  3. Onggo JR, et al. Robotic-assisted total knee arthroplasty is comparable to conventional total knee arthroplasty: a meta-analysis and systematic review. Arch Orthop Trauma Surg. 2020;140(10):1533-1549. doi:10.1007/s00402-020-03512-5
  4. Blackman BW, et al. Kinematic and mechanical alignment yield similar outcomes in total knee arthroplasty: a systematic review and a meta-analysis of randomized controlled trials. J Arthroplasty. 2026;41(10):3188-3198.e1. doi:10.1016/j.arth.2026.01.036
  5. Gusho C, et al. No superiority of total knee arthroplasty alignment philosophies: a network meta-analysis comparing mechanical, anatomical, kinematic, restricted kinematic, and functional alignment among randomized controlled trials. JBJS Rev. 2025;13(8):e25.00101. doi:10.2106/JBJS.RVW.25.00101
  6. Sarrel K, et al. Understanding economic analysis and cost-effectiveness of CT scan-guided, 3-dimensional, robotic-arm assisted lower extremity arthroplasty: a systematic review. J Comp Eff Res. 2024;13(4):e230040. Industry co-author. doi:10.57264/cer-2023-0040

All references