The Effect of Geometry on Patellar Tracking After TKA During Simulated Gait

2012 ◽  
Author(s):  
Lauren Ferris ◽  
Sami Shalhoub ◽  
Lorin Maletsky
Keyword(s):  
Cadaveric Study ◽  
Patellar Tracking ◽  
Implant Design ◽  
Ongoing Debate ◽  
Total Knee Replacements ◽  
Knee Replacements ◽  
Total Knee

Abnormal patellar tracking is the main cause of patellofemoral disorders and revision surgeries after total knee replacements (TKA) [1]. The decision to resurface or keep the natural patella has been an ongoing debate when performing TKA since patella morphology and femoral implant design affects patello-femoral (PF) kinematics during gait [2]. A previous study investigated the effects of resurfacing versus unresurfacing the patellae inter-specimen [3]. Error introduced in subject to subject studies can be reduced by performing a cadaveric study where PF kinematics for different patellae geometries are implanted in the same specimen. The purpose of this study was to measure PF kinematics in vitro during three simulated gait cycles with natural, unresurfaced, an anatomical design, and medialized dome patellae to determine the effects of different patellae design and gait cycles on PF kinematics.

Musculoskeletal Model During Treadmill Gait

2013 ◽  
Author(s):  
Mohammad Kia ◽  
Trent M. Guess ◽  
Antonis P. Stylianou
Keyword(s):  
Computational Models ◽  
Clinical Applications ◽  
Implant Design ◽  
Detailed Knowledge ◽  
Total Knee Replacements ◽  
Knee Replacements ◽  
Total Knee ◽  
Clinical Tools ◽  
Joint Loads

Detailed knowledge of joint kinematics and loading is essential for improving the design and surgical outcomes of total knee replacements as well as tissue engineering applications. Dynamic loading is a contributing factor in the development of joint osteoarthritis and in total knee replacement wear. Dynamic computational models in which muscle, ligament, and joint loads are predicted concurrently would be ideal clinical tools for surgery planning and for implant design. An important obstacle in clinical applications of computational models is validation of the estimated in-vivo loads.

The influence of design, materials and kinematics on the in vitro wear of total knee replacements

2005 ◽  
Vol 38 (2) ◽  
pp. 357-365 ◽  
Author(s):  
H.M.J. McEwen ◽  
P.I. Barnett ◽  
C.J. Bell ◽  
R. Farrar ◽  
D.D. Auger ◽  
...  
Keyword(s):  
Total Knee Replacements ◽  
Knee Replacements ◽  
Total Knee ◽  
Design Materials

An efficient and robust simulator for wear of total knee replacements

2020 ◽  
Vol 234 (9) ◽  
pp. 921-930
Author(s):  
Ansgar Burchardt ◽  
Christian Abicht ◽  
Oliver Sander
Keyword(s):  
Implant Design ◽  
In Vitro Tests ◽  
Simulation Methods ◽  
Contact Algorithm ◽  
Total Knee Replacements ◽  
Compliance Testing ◽  
Knee Replacements ◽  
Physical Tests ◽  
Total Knee ◽  
Simulation Results

Wear on total knee replacements is an important criterion for their performance characteristics. Numerical simulations of such wear have seen increasing attention over the last years. They have the potential to be much faster and less expensive than the in vitro tests in use today. While it is unlikely that in silico tests will replace actual physical tests in the foreseeable future, a judicious combination of both approaches can help making both implant design and pre-clinical testing quicker and more cost-effective. The challenge today for the design of simulation methods is to obtain results that convey quantitative information and to do so quickly and reliably. This involves the choice of mathematical models as well as the numerical tools used to solve them. The correctness of the choice can only be validated by comparing with experimental results. In this article, we present finite element simulations of the wear in total knee replacements during the gait cycle standardized in the ISO 14243-1 document, used for compliance testing in several countries. As the ISO 14243-1 standard is precisely defined and publicly available, it can serve as an excellent benchmark for comparison of wear simulation methods. We use comparatively simple wear and material models, but we solve them using a new wear algorithm that combines extrapolation of the geometry changes with a contact algorithm based on nonsmooth multigrid ideas. The contact algorithm works without Lagrange multipliers and penalty parameters, achieving unparalleled stability and efficiency. We compare our simulation results with the experimental data from physical tests using two different actual total knee replacements. Even though the model is simple, we can predict the total mass loss due to wear after 5-million gait cycles, and we observe a good match between the wear patterns seen in experiments and our simulation results. When compared with a state-of-the-art penalty-based solver for the same model, we measure a roughly fivefold increase of execution speed.

Effect of Kinematics on the Wear Rate of the Patella Femoral Artificial Joint

2011 ◽  
Author(s):  
Raman Maiti ◽  
John Fisher ◽  
Zhongmin Jin ◽  
Liam Rowley ◽  
Louise Jennings
Keyword(s):  
Wear Rate ◽  
Success Rate ◽  
Degrees Of Freedom ◽  
Artificial Joint ◽  
Six Degrees Of Freedom ◽  
Total Knee Replacements ◽  
The Past ◽  
Knee Replacements ◽  
Total Knee

Total knee replacements (TKR) have been used for the past four decades [1]. Conventional knee (tibiofemoral) wear simulators have been used to facilitate improvements in the design of TKRs [2]. This, along with surgical improvements has caused the success rate of implants to increase to 97% over a period of ten years [3, 4, and 5]. However the decision to resurface the patella still remains an issue [6, 7]. Research has been performed into the in vitro wear simulation of the patella femoral joint (PFJ) [8, 9, and 10] but to date none of these simulations have employed all six degrees of freedom (DOF).

scholarly journals Roughness Digital Characterization and Influence on Wear of Retrieved Knee Components

2021 ◽  
Vol 11 (23) ◽  
pp. 11224
Author(s):  
Saverio Affatato ◽  
Alessandro Ruggiero ◽  
Silvia Logozzo ◽  
Maria Cristina Valigi
Keyword(s):  
Wear Behavior ◽  
Surface Characteristics ◽  
Lateral Part ◽  
Knee Prostheses ◽  
Total Knee Replacements ◽  
Knee Replacements ◽  
Total Knee ◽  
Digital Methods

Tribological performance of knee components are strongly related to the surface characteristics. Primarily, the roughness and its 3D distribution on the surfaces affect the joint performance. One of the main limitations related to the tribological study of knee prostheses is that most of the research studies report in vitro or in silico results, as knee retrievals are difficult to find or are too damaged to be analyzed. This paper is focused on the roughness characterization of retrieved metal femoral components of total knee replacements (TKR) by means of a rugosimeter and involving digital methods to reconstruct the 3D topography of the studied surfaces. The aim of this study is to investigate how changes and distribution of roughness are correlated between the medial vs. the lateral part and how the resulting digital topography can give insights about the wear behavior.

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