What are the advantages of robotic Total Knee Replacement (TKR)?

Robotic Total Knee Replacement: Limited Advantages Not Supported by Guidelines

The American Academy of Orthopaedic Surgeons provides strong evidence against routine use of robotic-assisted or navigation technology in total knee arthroplasty because there is no difference in patient outcomes or complications compared to conventional instrumentation. 1, 2

Guideline Position on Robotic TKA

The AAOS explicitly recommends NOT using intraoperative navigation or patient-specific instrumentation in TKA, as these additive technologies increase procedural complexity and cost without improving patient outcomes. 1 This recommendation is based on strong evidence showing no difference in clinical results between robotic/navigation-assisted and conventional techniques. 3

Benchmark Performance of Conventional TKA

Conventional manual TKA already achieves 89% good or excellent outcomes for pain and function up to 5 years after surgery, establishing a high-quality standard that robotic assistance has failed to surpass in terms of meaningful clinical outcomes. 1, 2

Technical Advantages (Without Clinical Benefit)

While robotic systems demonstrate technical superiority in several measurable parameters, these improvements have not translated into better patient outcomes:

Improved Accuracy and Precision

• Component positioning deviates less from planned alignment: femoral positioning 0.9° vs 1.7°, tibial positioning 0.3° vs 1.3°, and mechanical axis alignment 1.0° vs 2.7° (all p < 0.001). 4
• Polyethylene insert thickness shows less deviation from plan: 1.4 mm vs 2.7 mm (p < 0.001). 4
• Tibial posterior slope accuracy improves: -0.3° deviation vs 1.7° deviation (p < 0.001). 4
• Mean difference between planned and achieved alignment is 0.8° with robotics vs 2.6° with manual technique. 5

Reduced Surgical Revisions During Procedure

• Fewer intraoperative distal femoral recuts required: 10% vs 22% (p = 0.033). 4

Soft Tissue Preservation

• Robotic systems enable precise bone registration and resection, theoretically reducing manual errors and minimizing soft tissue injury. 6
• Real-time incorporation of soft-tissue laxity data into the surgical plan before bone resection. 4

Patient-Reported Outcomes: Marginal at Best

Short-Term Subjective Benefits

• Some patients report the robotic knee feels "more natural" and less painful in bilateral comparison studies, though PROMs are comparable. 7
• Faster independent ambulation may occur, but clinical significance is questionable. 7
• Higher patient satisfaction scores reported in some studies, though functional outcomes remain equivalent. 7
• Forgotten Joint Score slightly better (73 vs 70.3, p < 0.01) but not clinically relevant. 7

No Long-Term Outcome Improvement

• Despite improved technical accuracy, no demonstrable advantages in long-term pain relief, function, or revision rates have been proven. 1
• The theoretical benefit of reduced implant loosening due to better alignment remains unproven and requires long-term studies. 5

Significant Disadvantages

Increased Complexity and Cost

• Requires placement of fiducial markers for bone registration. 5
• Significantly increased operating times. 5
• Higher overall procedural costs without corresponding improvement in outcomes. 5, 1
• Greater setup time and equipment requirements. 3

Technical Limitations

• Friction from robotic movement can disrupt probe insulation sheaths. 3
• Limited availability in many surgical centers. 3
• Requires additional training and learning curve for surgical teams. 5

Clinical Bottom Line

Robotic TKA should not be used routinely. While it achieves superior technical precision in component positioning and alignment, this accuracy has not translated into improved patient-centered outcomes such as pain relief, function, satisfaction, or reduced revision rates. 1, 2 The technology adds cost, complexity, and operative time without providing clinical benefit over conventional TKA, which already achieves excellent results in 89% of patients. 1

The only potential justification for robotic assistance would be in complex cases requiring highly individualized component positioning, though even this remains unproven. For standard primary TKA, conventional manual techniques remain the evidence-based standard of care. 3, 1