A New Load Application System for In Vitro Study of Ligamentous Injuries to the Human Knee Joint

2009 ◽  
pp. 232-232-12
Author(s):  
JM Bach ◽  
ML Hull
Keyword(s):  
Knee Joint ◽  
In Vitro Study ◽  
Vitro Study ◽  
Load Application ◽  
Application System ◽  
Human Knee ◽  
Human Knee Joint

A New Load Application System for In Vitro Study of Ligamentous Injuries to the Human Knee Joint

1995 ◽  
Vol 117 (4) ◽  
pp. 373-382 ◽  
Author(s):  
J. M. Bach ◽  
M. L. Hull
Keyword(s):  
Knee Joint ◽  
Degree Of Freedom ◽  
Load Application ◽  
Accuracy Evaluation ◽  
Application System ◽  
Human Knee ◽  
Human Knee Joint ◽  
Flexion Extension ◽  
External Loads

This paper describes the design and accuracy evaluation of a new six degree of freedom load application system for in vitro testing of the human knee joint. External loads of both polarity in all six degrees of freedom can be applied either individually or in any combination while the knee is permitted to move unconstrained in response to applied loads. The flexion/extension degree of freedom permits the full physiological range of motion. In addition to external loads, forces of the three major muscle groups (quadriceps, hamstrings, gastrocnemius) crossing the joint can be developed. Full automation and rapid convergence of loads to programmed values are achieved through a computer which feeds command signals to servo controller/electro-pneumatic servo valves. The servo valves regulate pressure to pneumatic actuators which develop the various loads. Experiments undertaken to quantify the accuracy of both load and displacement measurements reveal that errors particularly in load measurement are effectively controlled through the apparatus design.

Behavior of implant and abutment sets of three different connections during the non-axial load application: An in vitro experimental study using a radiographic method

2021 ◽  
pp. 1-12
Author(s):  
Sergio Alexandre Gehrke ◽  
Berenice Anina Dedavid ◽  
José Manuel Granero Marín ◽  
Luigi Canullo
Keyword(s):  
Experimental Study ◽  
Digital Radiography ◽  
Axial Load ◽  
In Vitro Study ◽  
Vitro Study ◽  
Load Application ◽  
Radiographic Method ◽  
Radiography System ◽  
Torque Values

BACKGROUND: During the masticatory cycle, loads of different intensities and directions are received by the dental structures and/or implants, which can cause micromovements at the junction between the abutment and implant. OBJECTIVE: The objective of this in vitro study was to evaluate the behavior of three different implant connections subjected to different load values using a digital radiography system. Additionally, the torque values for removing the abutment screws were also measured and compared. METHODS: Ninety sets of implant and abutment (IA) were used, divided into three groups according to the type of connection (n = 30 per group): EH group, external hexagon type connection; IH group, internal hexagon connection; and, MT group, Morse taper connection. RESULTS: MT group showed the better vertical misfit behavior at the three intensity of load applied, in comparison with EH and IH groups. In the analysis of torque maintenance (detorque test), MT group showed higher values of detorque when compared with the measured values of EH and IH groups (p < 0.001). CONCLUSIONS: The IA sets of EH and IH groups showed a microgap in all levels of applied loads, unlike the MT group this event was not observed. In the detorque test, MT group increase in the torque values when compared to the initial torque applied, unlike EH and IH groups showed a decrease in the initially torque applied in all conditions tested. A positive correlation was detected between the misfit and detorque values.

In vitro study of inter-individual variation in posterior slope in the knee joint

2009 ◽  
Vol 24 (6) ◽  
pp. 488-492 ◽  
Author(s):  
Johannes J. de Boer ◽  
Leendert Blankevoort ◽  
Idsart Kingma ◽  
Willie Vorster
Keyword(s):  
Knee Joint ◽  
Individual Variation ◽  
In Vitro Study ◽  
Vitro Study ◽  
Posterior Slope

In vitro study of contact area and pressure distribution in the human knee after partial and total meniscectomy

1993 ◽  
Vol 17 (4) ◽  
Author(s):  
J.C. Ihn ◽  
S.J. Kim ◽  
I.H. Park
Keyword(s):  
Pressure Distribution ◽  
Contact Area ◽  
In Vitro Study ◽  
Vitro Study ◽  
Human Knee

scholarly journals Zonal T2* and T1Gd assessment of knee joint cartilage in various histological grades of cartilage degeneration: an observational in vitro study

BMJ Open ◽  
2015 ◽  
Vol 5 (2) ◽  
pp. e006895-e006895 ◽  
Author(s):  
B. Bittersohl ◽  
H. S. Hosalkar ◽  
F. R. Miese ◽  
J. Schibensky ◽  
D. P. Konig ◽  
...  
Keyword(s):  
Knee Joint ◽  
In Vitro Study ◽  
Cartilage Degeneration ◽  
Vitro Study ◽  
Joint Cartilage

Misfit of Three Different Implant-Abutment Connections Before and After Cyclic Load Application: An In Vitro Study

2017 ◽  
Vol 32 (4) ◽  
pp. 822-829 ◽  
Author(s):  
Sergio Gehrke ◽  
Rafael Delgado-Ruiz ◽  
Juan Frutos ◽  
María Prados-Privado ◽  
Berenice Dedavid ◽  
...  
Keyword(s):  
Cyclic Load ◽  
In Vitro Study ◽  
Vitro Study ◽  
Load Application ◽  
Implant Abutment ◽  
Before And After

An in-vitro study of human knee kinematics: natural vs. replaced joint

2009 ◽  
pp. 1867-1870
Author(s):  
Bernardo Innocenti ◽  
L. Labey ◽  
J. Victor ◽  
P. Wong ◽  
J. Bellemans
Keyword(s):  
Knee Kinematics ◽  
In Vitro Study ◽  
Vitro Study ◽  
Human Knee

scholarly journals Direct Validation of Human Knee-Joint Contact Mechanics Derived From Subject-Specific Finite-Element Models of the Tibiofemoral and Patellofemoral Joints

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Wei Gu ◽  
Marcus G. Pandy
Keyword(s):  
Finite Element ◽  
Knee Joint ◽  
Contact Mechanics ◽  
Contact Pressure ◽  
Weight Bearing ◽  
Human Knee ◽  
Human Knee Joint ◽  
Joint Contact ◽  
Joint Contact Pressure

Abstract The primary aim of this study was to validate predictions of human knee-joint contact mechanics (specifically, contact pressure, contact area, and contact force) derived from finite-element models of the tibiofemoral and patellofemoral joints against corresponding measurements obtained in vitro during simulated weight-bearing activity. A secondary aim was to perform sensitivity analyses of the model calculations to identify those parameters that most significantly affect model predictions of joint contact pressure, area, and force. Joint pressures in the medial and lateral compartments of the tibiofemoral and patellofemoral joints were measured in vitro during two simulated weight-bearing activities: stair descent and squatting. Model-predicted joint contact pressure distribution maps were consistent with those obtained from experiment. Normalized root-mean-square errors between the measured and calculated contact variables were on the order of 15%. Pearson correlations between the time histories of model-predicted and measured contact variables were generally above 0.8. Mean errors in the calculated center-of-pressure locations were 3.1 mm for the tibiofemoral joint and 2.1 mm for the patellofemoral joint. Model predictions of joint contact mechanics were most sensitive to changes in the material properties and geometry of the meniscus and cartilage, particularly estimates of peak contact pressure. The validated finite element modeling framework offers a useful tool for noninvasive determination of knee-joint contact mechanics during dynamic activity under physiological loading conditions.

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