Assessment of paradoxical anterior translation in a CR total knee prosthesis coupling dynamic RSA and FE techniques

Journal of Experimental Orthopaedics

Bernardo Innocenti¹  Raffaele Zinno²  Laura Bragonzoni²  Stefano Zaffagnini³  Tommaso Ingrassia⁴  Agostino Igor Mirulla⁵ 

[1] BEAMS Department (Bio Electro and Mechanical Systems), Université Libre de Bruxelles, Bruxelles, Belgium;Department for Life Quality Studies, University of Bologna, Rimini, Italy;Department of Biomedical and Neuromotor Sciencies, Università di Bologna, Bologna, BO, Italy;2nd Orthopaedic and Traumatologic Clinic, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy;Department of Engineering, University of Palermo, Palermo, Italy;Department of Engineering, University of Palermo, Palermo, Italy;Department of Biomedical and Neuromotor Sciencies, Università di Bologna, Bologna, BO, Italy;

关键词: Dynamic RSA;    FE analysis;    TKA;    Mobile bearing;    Kinematics;   

DOI  :  10.1186/s40634-021-00361-y

来源: Springer

【 摘 要 】

PurposeThe study aims were to assess the kinematic data, Internal-External (IE) rotation, and Antero-Posterior (AP) translation of the contact points between the femoral condyles and polyethylene insert and to develop a combined dynamic RSA-FE (Radiostereometric – Finite Element) model that gives results congruent with the literature.MethodsA cohort of 15 patients who underwent cemented cruciate-retaining highly congruent mobile-bearing total knee arthroplasty were analyzed during a sit-to-stand motor task. The kinematical data from Dynamic RSA were used as input for a patient-specific FE model to calculate condylar contact points between the femoral component and polyethylene insert.ResultsThe femoral component showed an overall range about 4 mm of AP translation during the whole motor task, and the majority of the movement was after 40° of flexion. Concerning the IE rotation, the femoral component started from an externally rotate position (− 6.7 ± 10°) at 80° of flexion and performed an internal rotation during the entire motor task. The overall range of the IE rotation was 8.2°.ConclusionsDuring the sit to stand, a slight anterior translation from 40° to 0° of flexion of the femoral component with respect to polyethylene insert, which could represent a paradoxical anterior translation. Despite a paradoxical anterior femoral translation was detected, the implants were found to be stable. Dynamic RSA and FE combined technique could provide information about prosthetic component’s stress and strain distribution and the influence of the different designs during the movement.

【 授权许可】

CC BY