A Spine Surgeon's Guide to Instruments in Robotic Spine Surgery

Robotic spine surgery represents a major leap forward in precision and efficiency in spinal procedures. However, the effectiveness of these surgeries hinges on the proper understanding and use of specialized instruments. In this guide, we delve into the various instruments used in robotic spine surgery, their properties, uses, advantages, and limitations.

1. Navlock Trackers

• Purpose: Identify predetermined instruments on navigation.

• Types:

  • Large Navlocks (blue and black) for long instruments.

  • Small Navlocks (orange, green, grey, and purple) for short instruments.

• Key Features:

  • Attach reflective marker spheres (glions) via posts.

  • Enable accurate tracking of instrument position and orientation through navigation cameras.

  • Easily attachable to Navlock-compatible instruments.

2. Instrument Setup

• Console Role: Ensures proper matching of Navlock colors to their respective instruments.

• Usage:

  • Larger blue and black Navlocks are paired with long tools.

  • Smaller Navlocks are assigned to short instruments.

3. Robotic Arm-Guided Surgical Knife Handles

• Design: Compatible with 4.75 mm and 5.5 mm systems for precise skin and fascia incisions.

• Usage Tips:

  • For upper screw placement, gently pull skin upwards.

  • For caudal screws, pull skin caudally to accommodate additional screws through a single incision.

  • In paramedian approaches, watch for potential bleeders.

4. Navigated Dilator

• Function: Creates access through muscles and fascia using a Navlock-attached atraumatic design.

• Usage:

  • Establishes the initial pathway for sleeve insertion.

  • Avoid pushing against bone to minimize the risk of skiving.

5. Sleeves (Short & Long)

• Design: Available for 4.75 mm and 5.5 mm systems in both short and long sizes.

• Usage:

  • Inserted after the dilator, then pulled back by 2 mm to relieve bone pressure.

  • Creates a protected corridor, allowing tools to reach full speed before contacting the bone.

6. Feather Touch Drill

• Specifications: High-speed drill operating at 75,000 RPM with a drill bit size of 3 mm x 30 mm.

• Application:

  • Creates pilot holes for taps and screws.

  • Requires minimal force; use a two-finger technique for precision.

• Technique:

  • Start at maximum speed in the air before contacting the bone to prevent skiving.

  • Utilize the "Woodpecker Technique" for precision as shown in the video.

  
  

Skiving

• Risks: Higher on:

  • Hard, rounded bones.

  • Excess soft tissue pressure on the robot arm.

  • Blunt instruments or steep entry angles.

  • Forced sleeves against bone.

• Solutions:

  • Use high-speed drills and start them in the air.

    
    
    
    

  • Flatten bony surfaces and use sharp taps.

  • Employ power instruments and avoid forcing tools.

  • In lumbar spine procedures, use a "valley, not hill" approach for optimal entry angles.

  

7. Taps (Long & Short)

• Purpose: Create threads in pilot holes for secure screw placement.

• Sizes: Available from 4.0 to 7.5 mm.

• Usage:

  • Compatible with PowerEase and Navlock systems.

  • Advisable to "undertap" by 1–2 mm to improve pull-out strength.

8. Screw Drivers (MAS and MARS)

• Types:

  • MAS (MultiAxial Screw) drivers.

  • MARS (MultiAxial Reduction Screw) drivers.

• Design:

  • Compatible with Solera systems in India; Voyager and Modulex systems in the West.

  • Two lengths: 230 mm for long trajectories and 160 mm for short trajectories.

• Feature: The screwdriver shaft serves as a directional indicator for the screw tulip.

9. Midas Rex 8 (MR8 - 75,000 RPM) & PowerEase

• Midas Rex 8 (MR8):

  • Electric drill with foot pedal control.

  • Offers various attachments like burrs and drills.

• PowerEase:

  • High torque power instrument with adaptive trigger control for RPM adjustments.

  • Includes forward and reverse controls.

• Benefits:

  • Reduces surgeon fatigue.

  • Minimizes skiving during tapping and screw placement.

10. Integrated Power Console (IPC)

• Purpose: Central power management system for cutting and drilling tools.

• Features:

  • Supports drills, burrs, and saws.

  • Allows simultaneous connection of two instruments.

  • Ergonomic multifunction foot pedal for control.

  • Touchscreen menu for intuitive operation.

11. Stealth Midas

• Combines MR8 with advanced navigation capabilities.

• Applications:

  • Used for osteotomies, corpectomies, facetectomies, posterior vertebral column reconstruction (PVCR), and hemivertebra excision.

  • Ensures precise navigated burring and drilling of bone.

12. Blunt Passive Planar Probe

• Design: Lightweight and atraumatic.

• Function: Marks anatomical regions and checks navigation accuracy.

• Application: Useful for mapping regions of interest with navigation systems.

13. Passive Marker Spheres (Glions)

• Purpose: Enable precise 3D positioning of surgical tools.

• Features:

  • Sterile, disposable, and easy to set up.

  • Reduce reliance on fluoroscopy.

  • Create fixed navigation points with continuous tracking.

• Challenges:

  • Erosions or blood can prevent detection by navigation systems.

Conclusion

Robotic spine surgery instruments are engineered for precision, safety, and efficiency. By understanding their properties, uses, and challenges, surgeons can maximize outcomes while minimizing risks. Mastering these tools and their techniques is essential for advancing the field of robotic spine surgery.