THE HAPTIC ROBOT: THE HAND THAT GUIDES YOU

Abstract

1. 1.

   Role of enabling technologies in THA: Setting the stage

   1. a.

      Impact of component position in THA

      1. 1.

         Wear/lysis

         • Effect of edge loading, impingement

      2. 2.

         Instability

         • Together, the most common cause for revision hip arthroplasty

   2. b.

      Ideal component position:

      1. 1.

         Work of Lewinneck: the “safe zone” for stability

   3. c.

      Can we achieve this?

      1. 1.

         HSS study

      2. 2.

         Mass General Study: 2000 THR's, only 50% within desired range

   4. d.

      Need for assistance? Maybe?

2. 2.

   Types of Guidance:

   1. a.

      Navigation: use of mechano or optical tracking system that after some registration acquisition, facilitate spatial placement. The systems can either be image based (pre-operative CT scan) or imageless where multiple points are acquired and a “best fit” is matched to a library of pelvic geometries.

   2. b.

      Robotics: combines the spatial application of navigation with the precision bone preparation afforded by robotic milling. Robotic use can either be active whereby the robotic preparation is performed by the computer driven system (ie ROBODOC™). Alternatives include surgeon controlled but robot guided (haptic) type systems.

3. 3.

   Perceived Advantages:

   1. a.

      Robotic assisted: Bone preparation: spherical shape of socket consistently “rounder” than manually controlled reaming

      Implant insertion: by establishing boundaries of insertion, final implant position achieves desired position

4. 4.

   Unknowns:

   1. a.

      Cost effectiveness

   2. b.

      Do we really know where the socket is best located for an individual patient?

      While we rely on the safe zone of Lewinneck for our desired implant position, the impact of lumbosacral disease deformity could/should impact where the socket is placed.