title: Evaluation of predicted knee function for component malrotation in total knee arthroplasty.
abstract: Soft-tissue balancing for total knee arthroplasty (TKA) remains subjective and highly dependent on surgical expertise. Pre-operative planning may support the clinician in taking decisions by integrating subject-specific computer models that predict functional outcome. However, validation of these models is essential before they can be applied in clinical practice. The aim of this study was to evaluate a knee modelling workflow by comparing experimental cadaveric measures to model-based kinematics and ligament length changes. Subject-specific models for three cadaveric knees were constructed from medical images. The implanted knees were mounted onto a mechanical rig to perform squatting, measuring kinematics and ligament length changes with optical markers and extensometers. Coronal malrotation was introduced using tibial inserts with a built-in slope. The model output agreed well with the experiment in all alignment conditions. Kinematic behaviour showed an average RMSE of less than 2.7mm and 2.3° for translations and rotations. The average RMSE was below 2.5% for all ligaments. These results show that the presented model can quantitatively predict subject-specific knee behaviour following TKA, allowing evaluation of implant alignment in terms of kinematics and ligament length changes. In future work, the model will be used to evaluate subject-specific implant position based on ligament behaviour.
authors.affiliation: Biomechanics Section, Katholieke Universiteit Leuven, Celestijnenlaan 300C, 3001 Leuven, Belgium; Materialise N.V., Technologielaan 15, 3001 Leuven, Belgium. Electronic address: valentine.vanheule@kuleuven.be.
authors.forename: Valentine
authors.initials: V
authors.lastname: Vanheule
authors.affiliation: Department of Orthopaedics, University Hospital Pellenberg, Katholieke Universiteit Leuven, Weligerveld 1, 3212 Pellenberg, Belgium.
authors.forename: Hendrik Pieter
authors.initials: HP
authors.lastname: Delport
authors.affiliation: Department of Mechanical and Manufacturing Engineering, Aalborg University, Fredrik Bajers Vej 5, 9100 Aalborg, Denmark.
authors.forename: Michael Skipper
authors.initials: MS
authors.lastname: Andersen
authors.affiliation: Department of Orthopaedics, University Hospital Pellenberg, Katholieke Universiteit Leuven, Weligerveld 1, 3212 Pellenberg, Belgium.
authors.forename: Lennart
authors.initials: L
authors.lastname: Scheys
authors.affiliation: Materialise N.V., Technologielaan 15, 3001 Leuven, Belgium.
authors.forename: Roel
authors.initials: R
authors.lastname: Wirix-Speetjens
authors.affiliation: Department of Kinesiology, Katholieke Universiteit Leuven, Tervuursevest 101, 3001 Leuven, Belgium.
authors.forename: Ilse
authors.initials: I
authors.lastname: Jonkers
authors.affiliation: Department of Physical Medicine and Orthopedic Surgery, Ghent University, De Pintelaan 185, 9000 Ghent, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Victor
authors.affiliation: Biomechanics Section, Katholieke Universiteit Leuven, Celestijnenlaan 300C, 3001 Leuven, Belgium.
authors.forename: Jos
authors.initials: J
authors.lastname: Vander Sloten
mesh_terms: D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena; D006801:Humans; D007717:Knee / Q000000981:diagnostic imaging / Q000502:physiology*; D008022:Ligaments / Q000000981:diagnostic imaging / Q000502:physiology; D066230:Patient-Specific Modeling; D012399:Rotation; D014057:Tomography, X-Ray Computed
keywords: Alignment; In vitro; Kinematic knee rig; Soft tissue balancing; Subject-specific