Thomas C. Kienzle

Registration and immobilization in robot-assisted surgery.

Robotic systems for computer-assisted surgery involve both tools and techniques that are new to the surgical arena. Registration and immobilization in particular are key problems. Registration is the spatial alignment of the coordinate frames of the robot, an anatomic object (e.g., a bone), and the preoperative plan (a computer model). Immobilization is necessary to maintain that alignment. We discuss various approaches to registration and immobilization and solutions appropriate for an orthopedic surgical system.

Total knee replacement

Describes a computer-assisted surgical system which uses a calibrated robot. The authors consider: total knee replacement surgery; motivation for robotic systems in total knee replacement; system operation; CT scan and preoperative planning; femoral fiducial location; femoral component placement; tibial fiducial location and component placement; fixturing; immobilization of the knee; immobilization of the pelvis and ankle; fiducial identification and registration; landmark pins; center of the femoral head; robot system and calibration; calibration using a telescopic ball-bar. >

An integrated CAD-robotics system for total knee replacement surgery

An integrated system has been developed that allows the surgeon to more accurately place implant components during total knee surgery. A graphic computer displaying 3-D CT (computed tomography) data of the patients knee is used to perform more informed and accurate preoperative planning. In the operating room, a robot and specially designed fixturing aid the surgeon in performing the bone resections as determined in the preoperative plan. Crucial to the accuracy of this system is the rigid immobilization of the involved bones and the robots ability to determine their exact locations in space. The rationale and an overview of this system are presented as well as a discussion of some of the technical issues that have arisen.<<ETX>>

A CAD-based human interface for preoperative planning of total knee surgery

To aid an orthopedic surgeon in performing total knee replacement surgery, a computer-aided-design (CAD)-based graphic system is proposed for preoperative planning. This system consists of two parts. The first part reads the computed tomography (CT) scan data for the patients leg and performs image analysis on the graphics computer. To interact with the surgeons examination, CT images are manipulable on a high-resolution monitor. The output of this image analysis will be the extracted wire-frame data of the patients leg bones and certain pins inserted previously into the femur and tibia for surgery. These data will be the input of the second part of the system, a 3-D graphic training system that emulates the procedures of total knee arthroplasty. This system will allow a surgeon to simulate the bone alignment, cutting, and implant placement.<<ETX>>