Have virtual total knee arthroplasty models improved to the point that they can tackle really complex knee cases as well as or possibly better than cadaveric models?
A team from the Columbia University Irving Medical Center and the Stryker Corporation set out to develop and evaluate a virtual posterior cruciate ligament (PCL) model to simulate native knee kinematics for component testing in TKA.
Their work, “Virtual reconstruction of the posterior cruciate ligament for mechanical testing of total knee arthroplasty implants,” was published in the November 21, 2019 edition of The Knee.
Nana Sarpong, M.D., M.B.A., orthopedic surgery resident at Columbia University Medical Center and co-author explained the genesis of this study to OTW, “Cadaveric knee studies are an option for mechanical studies of implants in total knee replacements, but they are complex, costly, and time intensive.”
“In the current study, we aimed to create and validate a virtual posterior cruciate ligament (PCL) model to simulate native knee kinematics for component testing in knee replacement surgery.”
The team used three human cadaveric knee specimens and mounted them in a six-axis joint simulator, digitizing the femoral and tibial ligament insertion points. The team first tested ligament stiffness and kinematics with the intact knee and followed that up by retesting after PCL transection. They then repeated the knee kinematic testing reconstructed the virtual PCL until it approximated that of the intact knee by achieving less than 10% random mean square (RMS) error.
Dr. Sarpong summarized the teams work for OTW, “We were able to successfully create the virtual three-bundle PCL model. The random mean square (RMS) error in the most important plane of motion (anterior–posterior) between the virtually reconstructed PCL and the intact knee (with an intact PCL) was within our target goal of <10%.”
“A virtual PCL allows the potential for robust and clinically meaningful pre-clinical testing of cruciate-retaining (CR) total knee replacement designs without the need for cadaveric specimens. This study indicated that a virtually reconstructed three-bundle model of the PCL simulated with a six-axis hydraulic joint simulator can restore knee kinematics.”
