Open AccessAssessment of paradoxical anterior translation in a CR total knee prosthesis coupling dynamic RSA and FE techniques
Author(s) -
Mirulla Agostino Igor,
Bragonzoni Laura,
Zaffagnini Stefano,
Ingrassia Tommaso,
Zinno Raffaele,
Innocenti Bernardo
Publication year - 2021
Publication title -
journal of experimental orthopaedics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 18
ISSN - 2197-1153
DOI - 10.1186/s40634-021-00361-y
Subject(s) - condyle , rotation (mathematics) , orthodontics , kinematics , range of motion , translation (biology) , prosthesis , femur , biomedical engineering , medicine , materials science , computer science , surgery , physics , artificial intelligence , chemistry , biochemistry , classical mechanics , messenger rna , gene
Purpose The 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. Methods A 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. Results The 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°. Conclusions During 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.