In vivo kinematics of knee replacement during daily living activities: Condylar and post-cam contact assessment by three-dimensional fluoroscopy and finite element analyses

Abstract

In total knee replacement, the investigation on the exact contact patterns at the post-cam in implanted patients from real in vivo data during daily living activities is fundamental for validating implant design concepts and assessing relevant performances. This study is aimed at verifying the restoration of natural tibio-femoral condylar kinematics by investigating the post-cam engagement at different motor tasks. An innovative validated technique, combining three-dimensional fluoroscopic and finite element analyses, was applied to measure joint kinematics during daily living activities in 15 patients implanted with guided motion posterior-stabilized total knee replacement. Motion results showed physiological antero-posterior translations of the tibio-femoral condyles for every motor task. However, high variability was observed in the position of the calculated pivot point among different patients and different motor tasks, as well as in the range of post-cam engagement. Physiological tibio-femoral joint rotations and contacts at the condyles were found restored in the present knee replacement. Articular contact patterns experienced at the post-cam were found compatible with this original prosthesis design. The present study reports replaced knee kinematics also in terms of articular surface contacts, both at the condyles and, for the first time, at the post-cam. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1396-1403, 2017.

Knee kinematics in bi-cruciate stabilized total knee arthroplasty during squatting and stair-climbing activities

“…4,19 Belvedere et al recently reported that anterior contact occurred in 40-60% of patients after JOURNEY I at knee extension during chair-rising, stair-climbing, and step-up. 20 Anterior cam-post contact after JOURNEY II BCS TKA was relatively low in this study during squatting (14%) and stair-climbing (27%) near extension. This finding suggests that the cam-post design for the JOURNEY II BCS TKA could result in lower cam-post stresses, thus reducing the risk for failure of the tibial post.…”

Sensitivity analysis of the material properties of different soft-tissues: implications for a subjectspecific knee arthroplasty

“…Modern finite element models are usually based on medical scans and possess a high accuracy of anatomical realism fundamental for the development of appropriate, reliable and effective tools aimed at supporting clinically-tailored questions 1 . Besides the simulation of the native joints, models are widely used for the prediction of the effects of degenerative pathologies, traumatic events as well as surgical repair and replacement strategie [2][3][4][5][6][7][8] . In particular, they are used for subject-specific analyses and for guiding the surgical pre-planning phase by comparing the effect of different designs of knee prostheses on the same patient [9][10][11][12][13] .…”

Can Computer-Assisted Total Knee Arthroplasty Support the Prediction of Postoperative Three-Dimensional Kinematics of the Tibiofemoral and Patellofemoral Joints at the Replaced Knee?

“…34,[36][37][38][39][40][41] In fact, after small technical adaptations, VFA can still be used to measure PFJ kinematics, as well as under loading conditions typical of daily living. [36][37][38]40 The general aim of this study was to analyze quantitatively the extent to which postoperative PFJ kinematics assessed at 6 months of follow-up after TKA mimics the intraoperative kinematics after final component implantation. The hypothesis is that intraoperative kinematics assessment of PFJ, as well as TFJ, after final component implantation is capable of predicting postoperative knee kinematics after TKA during activities of daily living.…”