Fixed Bearing Knee Congruency – Influence on Contact Mechanics, Abrasive Wear and Kinematics

2009 ◽  
Vol 32 (4) ◽  
pp. 213-223 ◽  
Author(s):  
Thomas M. Grupp ◽  
Dave Stulberg ◽  
Christian Kaddick ◽  
Allan Maas ◽  
Bernhard Fritz ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Contact Mechanics ◽  
Wear Behavior ◽  
Element Model ◽  
Contact Stresses ◽  
Fixed Bearing ◽  
Wear Rates ◽  
Surface Contact ◽  
Total Knee

The objective of our study was to evaluate the in vitro wear behavior of fixed bearing designs for total knee arthroplasty in relation to contact mechanics and resultant kinematics for different degrees of congruency. A finite element model was created for three knee articulations with increasing degrees of tibio-femoral congruency (flat, curved, and dished design). For the three different knee design configurations, in vitro wear simulation was performed according to ISO 14243–1. Contact areas increased with increasing knee congruency, whereas the peak surface contact stresses decreased. The wear rates for the knee design configurations differed substantially between the three test groups (flat, curved, and dished). Our observations demonstrate that increased congruency in conjunction with decreased surface contact stresses significantly contributes to reducing wear in fixed bearing knee articulations.

Effects of interference assembly of a tibial insert on the tibiofemoral contact mechanics in total knee replacement

2019 ◽  
Vol 233 (9) ◽  
pp. 948-953 ◽  
Author(s):  
Zhenxian Chen ◽  
Jing Zhang ◽  
Yongchang Gao ◽  
Shibin Chen ◽  
Xuan Zhang ◽  
...  
Keyword(s):  
Total Knee Replacement ◽  
Contact Mechanics ◽  
Knee Replacement ◽  
Articular Surface ◽  
Peak Load ◽  
Element Model ◽  
Fixed Bearing ◽  
Locking Mechanism ◽  
Tibial Insert ◽  
Total Knee

Tibial locking mechanism design is adopted to limit the backside micromotion in fixed-bearing total knee replacement. However, the effect of the interference assembly of a tibial insert on the tibiofemoral contact mechanics was usually ignored. Finite element model of a fixed-bearing total knee replacement with full peripheral locking mechanism was established to simulate the interference assembly of the tibial insert, and the corresponding effects on the tibiofemoral contact mechanics were predicted. Due to the interference assembly of the tibial insert, a maximum Mises stress of 3.24 MPa was found for the tibial insert before loading. Furthermore, the contact stress was increased by 8.77%, and the contact area was decreased by 5.43% under peak load. The interference assembly of the tibial insert in a fixed-bearing total knee replacement changed the tibiofemoral contact mechanics. This study indicated that the level of interference fit should be cautiously designed for the tibial locking mechanism in fixed-bearing total knee replacement for balancing the articular surface wear and the backside wear of the modular tibial insert.

Differences in patellofemoral contact stresses between mobile-bearing and fixed-bearing total knee arthroplasties: a dynamic in vitro measurement

2008 ◽  
Vol 129 (7) ◽  
pp. 901-907 ◽  
Author(s):  
Adrian Skwara ◽  
Carsten O. Tibesku ◽  
Sven Ostermeier ◽  
Christina Stukenborg-Colsman ◽  
Susanne Fuchs-Winkelmann
Keyword(s):  
Mobile Bearing ◽  
Contact Stresses ◽  
Total Knee Arthroplasties ◽  
Fixed Bearing ◽  
Total Knee

Femorotibial kinematics and load patterns after total knee arthroplasty: An in vitro comparison of posterior-stabilized versus medial-stabilized design

2016 ◽  
Vol 33 ◽  
pp. 42-48 ◽  
Author(s):  
Arnd Steinbrück ◽  
Christian Schröder ◽  
Matthias Woiczinski ◽  
Andreas Fottner ◽  
Vera Pinskerova ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Posterior Stabilized ◽  
Total Knee ◽  
In Vitro Comparison

scholarly journals Tranexamic Acid Increases Early Postoperative Pain and Decreases Time to First Opioid Following Total Knee Arthroplasty

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Sachin Seetharam ◽  
Sydney Keller ◽  
Mary Ziemba-Davis ◽  
R. Michael Meneghini MD
Keyword(s):  
Total Knee Arthroplasty ◽  
Postoperative Pain ◽  
Blood Loss ◽  
Tranexamic Acid ◽  
Knee Arthroplasty ◽  
Ex Vivo ◽  
Pain Scores ◽  
Average Pain ◽  
Total Knee

Background and Hypothesis: Tranexamic acid (TXA) decreases blood loss in total knee arthroplasty (TKA). However, TXA evoked pain in rats by inhibiting GABA and glycine receptors in the spinal dorsal horn, and caused cellular death in ex vivo and in vitro human periarticular tissues exposed to clinical concentrations of TXA. We evaluated inpatient postoperative pain and blood loss in TKA performed with and without TXA. Project Methods: 105 consecutive cemented TKAs without TXA were compared to 72 consecutive cemented TKAs with TXA. Procedures were performed by a single surgeon using identical perioperative medical and pain-control protocols. Outcomes included: average of q2-4 hour pain scores during the first 24 hours after PACU discharge, average pain during remainder of stay, final pain score prior to discharge, time in minutes to first opioid after PACU discharge, total opioids in morphine equivalents (MEQs) during the first 24 hours after PACU discharge, average MEQs per remaining days of stay, and mean g/dL pre- to postoperative decrease in hemoglobin. Multivariate analyses accounted for 15 demographics and covariates. Results: The sex (p=0.393), age (p=0.784), and BMI (p=0.930) of the two cohorts were similar. Mean pain during the first 24 hours was greater (4.1 vs. 3.2, p=0.001), MEQs consumed during the first 24 hours were greater (45 vs. 37, p=0.069), and time to first opioid medication was shorter (326 vs. 414, p=0.023) in patients who received TXA. The decrease in hemoglobin was less in patients who received TXA (-2.2 vs. -2.7, p<0.001).   Conclusion and Potential Impact: Our hypothesis based on animal and laboratory studies that TXA may increase early postoperative pain was confirmed by three metrics. Consistent with the effective life of TXA, pain and opioid consumption after 24 hours did not differ based on TXA use. Further work is warranted to investigate the nature consequences associated with TXA, relative to its demonstrated benefits for blood conservation.  

In vitro validation of a novel inertial-based cutting guide for tibial resection in total knee arthroplasty

The Knee ◽  
2020 ◽  
Vol 27 (5) ◽  
pp. 1433-1438
Author(s):  
Tommaso Bonanzinga ◽  
Alberto Giuffrida ◽  
Berardo Di Matteo ◽  
Giovanni Francesco Raspugli ◽  
Francesco Iacono ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Tibial Resection ◽  
Cutting Guide ◽  
Total Knee
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