Next Generation Knee Replacements: A New Approach to Replicate the Function of the ACL

2007 ◽  
Author(s):  
Gokce Yildirim ◽  
Peter S. Walker ◽  
Jonathan Sussman-Fort ◽  
Jason Boyer
Keyword(s):  
Daily Activities ◽  
Knee Joints ◽  
Knee Motion ◽  
New Approach ◽  
Total Knee Replacements ◽  
Natural Motion ◽  
Geometrical Features ◽  
Knee Replacements ◽  
Total Knee ◽  
Arthritic Knee

Current total knee replacements solve the problem of arthritic knee joints, but the evidence is that normal patterns of knee motions are not restored (1) In addition; paradoxical anterior sliding of the femur on the tibia can occur in the first half of the flexion range (2). Achieving natural motion is likely to be important for daily activities which involve higher angles of flexion, in terms of restoring normal soft tissue lengths and patello-femoral mechanics. Studies have shown the damaging effects of anterior femoral slide on the tibia affecting both the patella and the patellar tendon (3). Our paper examines new knee replacement designs which incorporate geometrical features to regain anatomical knee motion.

scholarly journals Computational study on lateral and medial wear characterization in knee implants by a multibody dynamic system

2021 ◽  
Author(s):  
G. Fekete
Keyword(s):  
Computational Study ◽  
Wear Model ◽  
Dynamic Simulations ◽  
Total Knee Replacements ◽  
Geometrical Features ◽  
Knee Replacements ◽  
Multibody Dynamic ◽  
Total Knee ◽  
Mechanical Factors ◽  
Multibody Dynamic System

AbstractWear is one of the main mechanical factors that limits the survival of total knee replacements (TKRs) and it is known to be highly dependent on the local kinematics of the knee joint. In this study, an analytical wear model was coupled to a multibody dynamic model to obtain wear distribution at the lateral and medial contact plateaus of different TKRs. The major aim was to analyze if wear distribution on the contact plateaus can be an indicator of elevated tibiofemoral misalignment which can lead to rapid TKR failure. For the multibody dynamic simulations, commercial and prototype TKR geometries were used, coupled with an augmented Archard’s law. Squat movement was chosen due to its importance both in sports and in everyday life. As a conclusion, a new parameter, denoted as wear imbalance, is introduced, which can indicate whether a TKR, due to its geometrical features, is prone to be subjected to elevated wear and failure.

scholarly journals Towards the understanding of lubrication mechanisms in total knee replacements – Part I: Experimental investigations

2021 ◽  
Vol 156 ◽  
pp. 106874 ◽  
Author(s):  
David Nečas ◽  
Martin Vrbka ◽  
Max Marian ◽  
Benedict Rothammer ◽  
Stephan Tremmel ◽  
...  
Keyword(s):  
Experimental Investigations ◽  
Total Knee Replacements ◽  
Knee Replacements ◽  
Total Knee ◽  
Lubrication Mechanisms

scholarly journals Amorphous Carbon Coatings for Total Knee Replacements—Part I: Deposition, Cytocompatibility, Chemical and Mechanical Properties

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1952
Author(s):  
Benedict Rothammer ◽  
Kevin Neusser ◽  
Max Marian ◽  
Marcel Bartz ◽  
Sebastian Krauß ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Amorphous Carbon ◽  
Detailed Characterization ◽  
Carbon Coatings ◽  
Dlc Coatings ◽  
Total Knee Replacements ◽  
Knee Replacements ◽  
Total Knee ◽  
Amorphous Carbon Coatings

Diamond-like carbon (DLC) coatings have the potential to reduce implant wear and thus to contribute to avoiding premature failure and increase service life of total knee replacements (TKAs). This two-part study addresses the development of such coatings for ultrahigh molecular weight polyethylene (UHMWPE) tibial inlays as well as cobalt–chromium–molybdenum (CoCr) and titanium (Ti64) alloy femoral components. While a detailed characterization of the tribological behavior is the subject of part II, part I focusses on the deposition of pure (a‑C:H) and tungsten-doped hydrogen-containing amorphous carbon coatings (a‑C:H:W) and the detailed characterization of their chemical, cytological, mechanical and adhesion behavior. The coatings are fabricated by physical vapor deposition (PVD) and display typical DLC morphology and composition, as verified by focused ion beam scanning electron microscopy and Raman spectroscopy. Their roughness is higher than that of the plain substrates. Initial screening with contact angle and surface tension as well as in vitro testing by indirect and direct application indicate favorable cytocompatibility. The DLC coatings feature excellent mechanical properties with a substantial enhancement of indentation hardness and elastic modulus ratios. The adhesion of the coatings as determined in modified scratch tests can be considered as sufficient for the use in TKAs.

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