TY - CHAP A1 - Andersen, Michael Skipper A1 - de Zee, Mark A1 - Dendorfer, Sebastian A1 - MacWilliams, Bruce A1 - Rasmussen, John T1 - Validation of a detailed lower extremity model based on the Klein Horsman data set T2 - Proceedings of the 12th International Symposium on Computer Simulation in Biomechanics (ISB 2009), July 2nd - 4th 2009, Cape Town, South Africa Y1 - 2009 SP - 27 EP - 28 ER - TY - JOUR A1 - Kummerlin, Jana A1 - Fabro, Hannah Katharina A1 - Pedersen, Peter Heide A1 - Jensen, Kenneth Krogh A1 - Pedersen, Dennis A1 - Andersen, Michael Skipper T1 - Measuring Knee Joint Laxity in Three Degrees-of-Freedom In Vivo Using a Robotics- and Image-Based Technology JF - Journal of Biomechanical Engineering N2 - Accurate and reliable information about three-dimensional (3D) knee joint laxity can prevent misdiagnosis and avoid incorrect treatments. Nevertheless, knee laxity assessments presented in the literature suffer from significant drawbacks such as soft tissue artifacts, restricting the knee within the measurement, and the absence of quantitative knee ligament property information. In this study, we demonstrated the applicability of a novel methodology for measuring 3D knee laxity, combining robotics- and image-based technology. As such technology has never been applied to healthy living subjects, the aims of this study were to develop novel technology to measure 3D knee laxity in vivo and to provide proof-of-concept 3D knee laxity measurements. To measure tibiofemoral movements, four healthy subjects were placed on a custom-built arthrometer located inside a low dose biplanar X-ray system with an approximately 60 deg knee flexion angle. Anteroposterior and mediolateral translation as well as internal and external rotation loads were subsequently applied to the unconstrained leg, which was placed inside a pneumatic cast boot. Bone contours were segmented in the obtained X-rays, to which subject-specific bone geometries from magnetic resonance imaging (MRI) scans were registered. Afterward, tibiofemoral poses were computed. Measurements of primary and secondary laxity revealed considerable interpersonal differences. The method differs from those available by the ability to accurately track secondary laxity of the unrestricted knee and to apply coupled forces in multiple planes. Our methodology can provide reliable information for academic knee ligament research as well as for clinical diagnostics in the future. KW - ANTERIOR CRUCIATE LIGAMENT KW - COMPLEX KW - COORDINATE SYSTEM KW - INJURY KW - INSTABILITY KW - MOTION KW - OSTEOARTHRITIS KW - QUANTIFICATION KW - STIFFNESS Y1 - 2022 U6 - https://doi.org/10.1115/1.4053792 SN - 1528-8951 VL - 144 IS - 8 PB - The American Society of Mechanical Engineers (ASME) ER -