Types of Robotic Systems Available for Total Knee Replacement
Critical Context: Evidence Does Not Support Routine Use of Robotic Systems
The American Academy of Orthopaedic Surgeons provides strong evidence against using intraoperative navigation or robotic systems for routine TKA, as no differences in outcomes or complications have been demonstrated compared with conventional instrumentation. 1, 2
Despite this guideline recommendation, multiple robotic platforms have been developed and are commercially available. Each system has distinct features and must be evaluated independently rather than as a generic "robotic" category. 3
Main Categories of Robotic Navigation Systems
The available systems can be classified into three main technological approaches: 4
- Image-based console navigation systems - utilize preoperative CT or MRI imaging for surgical planning 4
- Imageless console navigation systems - rely on intraoperative anatomic landmark registration without preoperative imaging 4
- Accelerometer-based handheld navigation systems - portable devices that provide real-time feedback 4
Specific Robotic Platforms Currently Available
ROBODOC (T-SOLUTION ONE)
- Oldest system with longest follow-up data (>10 years) showing no improved clinical outcomes compared to conventional TKA 3
- Originally adapted from the CASPAR system, which was the first commercial robotic system for TKA 5
- Uses CT-based preoperative planning with fiducial marker placement 5
- Historical data showed mean alignment difference of 0.8° versus 2.6° in manual controls, though this precision advantage did not translate to superior long-term clinical outcomes 3, 5
MAKO Robotic-Arm System
- Semi-constrained robotic arm with "haptic" boundaries that physically restricts bone resection outside planned parameters 6
- Utilizes preoperative 3D CT-based planning with image-based intraoperative navigation 6
- Provides integrated alignment, implant position, and gap balancing data with real-time modifications 6
- Incorporates kinetic sensors for three-dimensional soft tissue balancing and rotational assessment 6
- Registry data demonstrates improved outcome survivorship independent of surgeon volume and learning curves 6
- Initially developed for unicompartmental knee arthroplasty, later expanded to bicompartmental and total knee techniques 6
NAVIO (now CORI)
- Handheld robotic system with accelerometer-based navigation 3, 4
- Imageless technology that does not require preoperative CT scanning 3
- Limited published long-term clinical outcome data available 3
ROSA
- Console-based robotic platform 3
- Can function with or without preoperative imaging 3
- Heterogeneous outcomes regarding gap balance assessment and clinical correlation 3
OMNIBOT
- Less commonly used platform with limited published evidence 3
- Specific technical specifications vary from other systems 3
Common Characteristics Across All Systems
All robotic platforms demonstrate a similar learning curve based on operative time, though most require longer operative time compared to conventional TKA. 3
Radiological outcomes consistently show improved surgical precision in component alignment compared to manual techniques across all platforms, though this has not translated to proven improvements in clinical outcomes, implant survival, or patient satisfaction. 3, 7
Important Clinical Caveats
- Conventional TKA already achieves 89% good or excellent outcomes for pain and function up to 5 years, making it difficult for robotic systems to demonstrate superiority 2
- Up to 20% of TKA patients remain unsatisfied regardless of technique used 7
- Complications and revision rates for robotic systems (where published for ROBODOC and MAKO) show no clear differences compared to conventional TKA 3
- Current disadvantages include increased operative time, need for additional imaging or marker placement (system-dependent), and higher overall costs 3, 5