Artificial medial and lateral meniscus prostheses mimic kinematics of the native meniscus without affecting knee joint motion: A cadaveric study.

Purpose: This exploratory study tested the hypothesis that total medial and lateral meniscus prostheses have no adverse effect on range of motion, kinematics and laxity of the knee joint. Furthermore, it was investigated whether the prosthesis kinematics were similar to the native meniscus kinematics during flexion and under knee loading. Methods: A dedicated knee testing rig was used to apply different flexion angles and joint loads to 13 cadaveric knee joints. Roentgen stereophotogrammetric analysis (RSA) was used to analyse the kinematics of the knee joint and the meniscus. For both the medial and lateral compartment, linear mixed models were used to make a comparison between the native condition, the meniscectomized knee joint, a meniscal allograft transplant and the meniscus prosthesis. A Lachman test was simulated to measure the effect of the different meniscal conditions on anteroposterior knee laxity, with and without the anterior cruciate ligament intact. Results: None of the meniscal conditions restricted range of motion or adversely affected joint kinematics. During flexion and loading, the medial and lateral meniscus prostheses translated over the tibial plateau in a comparable way as the native meniscus, although some differences were identified. Anteroposterior knee laxity was not significantly altered by any of the meniscal conditions. Conclusions: The artificial medial and lateral meniscus prostheses did not affect knee range of motion. Only minor differences in knee joint and meniscus kinematics were found between the prostheses and the native meniscus, and no effect on joint laxity was found. Level of Evidence: Level V.