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).

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

The Effect of the Slip Ratio in Sagittal Plane on the Wear of UHMWPE Bearings in TKR

2012 ◽  
Vol 271-272 ◽  
pp. 1695-1699
Author(s):  
Hu Kun ◽  
Jin Yao
Keyword(s):  
Wear Rate ◽  
Contact Pressure ◽  
Sagittal Plane ◽  
Articular Surface ◽  
Wear Depth ◽  
Slip Ratio ◽  
Total Knee Replacements ◽  
Knee Replacements ◽  
Total Knee ◽  
Sliding Distance

Reducing the sliding distance by decreasing slip ratio which occur during knee articulation helps to reduce the wear rate of the ultra-high molecular polyethylene (UHMWPE) bearings in total knee replacements (TKR). However, in the limited space in knee, a smaller sagittal radius of femoral articular surface which leads to greater contact pressure that may aggravate wear is needed to make a smaller slip ratio possible. This paper described a model for evaluating the effect of slip ratio in sagittal plane on the wear depth of UHMWPE bearings. The results showed that decreasing the sagittal radius of femoral articular surface properly was an effective approach to reduce the wear of UHMWPE bearings.

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.

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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