Robot Assisted Total Knee Replacement

Problem Statement:  How can we minimize the number of knee replacement surgery revisions?

JR automation’s service division (Epoch Robotics) is sponsoring team 22 by lending a Fanuc LR mate 200id/7c for their senior design project.

Total Knee Replacement




Every total knee replacement (TKR) has about a 1% chance of failing every year after the initial surgery, meaning that 10% fail by the 10th year after installation and 20% before the 20th year, and once the TKR revision surgery is far more complex and likely to fail than doing it right the first time.

 It has already been proven that putting knee joint prosthetic on straighter (through surgeon cutting guide alignment verification steps) has proven to make each prosthetic 1.5% more likely last more last >9 rather than <9 years, while 1.5% seems small in 2013 when 600,000 TKR were performed in the US alone that is 6,300 failures prevented, and for the 2030 prediction of 3,000,000 annual american TKRs would mean 45,000 failures prevented merely by improved bone cut alignment.

Applying a robot would not only allow for precision application of cuts predetermined angles relative to bone position, but robots like the Fanuc LR mate 200id/7c being lent to team 22 by JR Automation have impressive repeatability of ±0.02mm, which applied to correctly to medical procedure will allow for better future research into slight micro adjustments in order to more precisely define and even customize straightness standards for TKR patients in the future.

The robot will assist the surgeon by making the five cuts to femur (distal, anterior, posterior, anterior chamfer, posterior chamfer) and one to tibia at the at precise predetermined (custom to patient and prosthetic) angles relative to the end of the bone for optimized fit with the joint prosthetic and aligned for a healthy range of motion and decreased wear which will result in reduced demand for revisions.

 Our Goal:

To advance automation in total knee replacement surgery by designing and building a fixturing system which will hold a patient’s leg still within tolerance during the operation to help in determining the femur’s precise position and orientation information. To validate the fixturing design, analogous surgical tooling will be designed or purchased and modified into a Robot EOA tool and a Robot workstation will be constructed.