P111 - Robotic Testing of Meniscal Biomechanics In Vitro Validation a Six Degree-of-freedom Robotic System
- M. Husen (Rochester, US)
- M. Husen (Rochester, US)
- A. Hooke (Rochester, US)
- D. Jacobson (Rochester, US)
- D. Saris (Rochester, US)
Abstract
Purpose
1) Introduce a novel expiremental model and design to induce isolated meniscal tears, 2) to present biomechanical and histological baseline data of the model and 3) to test novel meniscal reconstruction and regeneration methods with the new biomechanical model.
Methods and Materials
A 6 degree-of-freedom robotic arm (HR300 Ultra 2500, Kuka Robotics Corp, Augsburg, Germany) was used in this study. A custom robotic loading profile was created to stress the medial meniscus. The loading profile inludes holding the knee at 60° of flexion while simultaneously applying 1 bodyweight of compression and an internal rotation torque normalized to the specimen’s height and weight. The internal rotation torque was progressively increased from 50% of the normalized value in 10% intervals until significant meniscus damage is present or other knee stabilizing structures fail. The meniscus was visualized and monitored arthroscopically before and after each cycle by a fellowhip-trained orthopedic surgeon.
Results
A total of 3 samples were tested biomechanically. In one specimen a longitudinal tear of the posterior horn of the medial meniscus was induced alongside with an avulsion fracture of the tibial ACL (anterior cruciate ligament) insertion. In a second specimen an isolated radial tear of the meniscal body was induced without concomitant injuries and expanded with subsequent testing. The third specimen, belonging to a 55 year old body donor, sustained a partial tear of the ACL while no meniscal tear was observed.
Conclusion
Our results validate the use of a robotic system as a testing platform for uniquely stressing the meniscus. The robotic system demonstrated high repeatability during manipulation and superior accuracy. The results of this study will provide an effective means for further determination of native knee biomechanical properties and evaluation of the effect of meniscal pathology and surgical interventions during robotically applied motion cycles. The platform showcases promising potential for further specified meniscal testing.