Prediction of TKR Function Using Specimen Specific Robotically Calibrated Knee Models

Passive knee kinematics and kinetics following total knee replacement (TKR) are dependent on the topology of the component joint surfaces as well as the properties of the passive soft tissue structures (ligaments and capsule). Recently, explicit computer models have been used for the prediction of knee joint kinematics based on experimental investigations [1]. However, most of these models replicate experimental knee simulators [2], which simulate soft tissue structures using springs or elastomeric structures. New generations of experimental setups deploy industrial robots for measuring kinematics and kinetics in six degrees of freedom as well as the contribution of soft tissue structures. Based on these experiments, accurate soft tissue properties are available for use in computer models to aid more realistic predictions of kinematics. Final evidence of the quality of the kinematic predictions from these computer models can be provided by direct validation of the models against experimental data. Therefore, the objective of this study was to use in vitro robotic test data to develop, verify, and validate specimen specific virtual models suitable for predicting laxity and kinematics of the reconstructed knee.

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Real-Time in-Vitro Evaluation of Knee Kinematics Using Enriched Computed Tomography Data

10.29007/flk2 ◽

2018 ◽

Author(s):

Matthias Verstraete ◽

Nele Arnout ◽

Patrick De Baets ◽

Thibeau Vancouillie ◽

Tom Van Hoof ◽

...

Keyword(s):

Computed Tomography ◽

Real Time ◽

Degrees Of Freedom ◽

Knee Kinematics ◽

In Vitro Evaluation ◽

Golden Standard ◽

Infrared Cameras ◽

Real Time Information ◽

Registration Phase

In vitro evaluation of knee kinematics remains an essential part during pre-clinical testing of new implants and surgical procedures. To assess the kinematics, markers are rigidly attached to the bone segments and tracked using infrared cameras. Subsequently, the position of the markers relative to the bone is determined using computed tomography (CT). Although the accuracy of the aforementioned, CT-based method is not doubted, no real-time information is provided. Therefore, this paper presents a real-time method that uses a registration phase in combination with a pre-operative CT scan to determine the location of the bone relative to the markers. During this registration phase, the bone surface location is identified touching surface points with a tracked pen. The kinematic parameters obtained using this real-time method is compared to the golden standard, CT-based, method. Under optimal conditions, rotational and translational differences around 1mm and 1degree are obtained. This is in the range of the inter- and intra- observer variability in determining the landmarks used for these kinematic calculations. It is therefore concluded that the accuracy of the real-time method allows effectively evaluating the knee kinematics in six degrees of freedom.

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Design of a Tissue Resonator Indenter Device for Measurement of Soft Tissue Viscoelastic Properties Using Parametric Identification

Volume 3: ASME/IEEE 2009 International Conference on Mechatronic and Embedded Systems and Applications; 20th Reliability, Stress Analysis, and Failure Prevention Conference ◽

10.1115/detc2009-87786 ◽

2009 ◽

Author(s):

Alireza Hariri ◽

Jean W. Zu

Keyword(s):

Soft Tissue ◽

Viscoelastic Properties ◽

Degrees Of Freedom ◽

Mechanical Vibration ◽

State Space Model ◽

Parametric Identification ◽

Model Parameters ◽

Kelvin Model ◽

Tissue Properties ◽

New Device

The design of a new device called Tissue Resonator Indenter Device (TRID) for measuring soft tissue viscoelastic properties is presented. The two degrees-of-freedom device works based on mechanical vibration principles. When TRID comes into contact with a soft tissue, it can identify the tissue’s viscoelastic properties through the change of the device’s natural frequencies and damping ratios. In this paper, the deign of TRID is presented assuming Kelvin model for tissues. By working in the linear viscoelastic domain, TRID is designed to identify tissue properties in the range of 0–100 Hz. Assuming Kelvin model for tissues, the current paper develops a method for determining unknown tissue parameters using input-output data from TRID. Moreover, it is proved that the TRID’s parameters as well as the Kelvin tissue model parameters are globally identifiable. A parametric identification method using the prediction error approach is proposed for identifying the unknown tissue parameters in a grey-box state-space model. The reliability and effectiveness of the method for measuring soft tissue’s viscoelastic properties is demonstrated through simulation in the presence of considerable input and output noises.

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Evaluation of 99mTc-Label led Vitamin K4 as an Agent for Testicular Imaging

Nuklearmedizin ◽

10.1055/s-0038-1629552 ◽

1991 ◽

Vol 30 (01) ◽

pp. 35-39 ◽

Cited By ~ 1

Author(s):

H. S. Durak ◽

M. Kitapgi ◽

B. E. Caner ◽

R. Senekowitsch ◽

M. T. Ercan

Keyword(s):

Soft Tissue ◽

Room Temperature ◽

Normal Subjects ◽

Left Testis ◽

Wide Range ◽

Activity Ratios ◽

The Right ◽

Radioactivity Levels

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

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Quantification of assembly forces during creation of head-neck taper junction considering soft tissue bearing: a biomechanical study

Arthroplasty ◽

10.1186/s42836-021-00075-7 ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Toni Wendler ◽

Torsten Prietzel ◽

Robert Möbius ◽

Jean-Pierre Fischer ◽

Andreas Roth ◽

...

Keyword(s):

Soft Tissue ◽

Work Experience ◽

Soft Tissues ◽

Force Sensor ◽

Biomechanical Study ◽

Measuring System ◽

Wide Range ◽

Head Neck

Abstract Background All current total hip arthroplasty (THA) systems are modular in design. Only during the operation femoral head and stem get connected by a Morse taper junction. The junction is realized by hammer blows from the surgeon. Decisive for the junction strength is the maximum force acting once in the direction of the neck axis, which is mainly influenced by the applied impulse and surrounding soft tissues. This leads to large differences in assembly forces between the surgeries. This study aimed to quantify the assembly forces of different surgeons under influence of surrounding soft tissue. Methods First, a measuring system, consisting of a prosthesis and a hammer, was developed. Both components are equipped with a piezoelectric force sensor. Initially, in situ experiments on human cadavers were carried out using this system in order to determine the actual assembly forces and to characterize the influence of human soft tissues. Afterwards, an in vitro model in the form of an artificial femur (Sawbones Europe AB, Malmo, Sweden) with implanted measuring stem embedded in gelatine was developed. The gelatine mixture was chosen in such a way that assembly forces applied to the model corresponded to those in situ. A study involving 31 surgeons was carried out on the aforementioned in vitro model, in which the assembly forces were determined. Results A model was developed, with the influence of human soft tissues being taken into account. The assembly forces measured on the in vitro model were, on average, 2037.2 N ± 724.9 N, ranging from 822.5 N to 3835.2 N. The comparison among the surgeons showed no significant differences in sex (P = 0.09), work experience (P = 0.71) and number of THAs performed per year (P = 0.69). Conclusions All measured assembly forces were below 4 kN, which is recommended in the literature. This could lead to increased corrosion following fretting in the head-neck interface. In addition, there was a very wide range of assembly forces among the surgeons, although other influencing factors such as different implant sizes or materials were not taken into account. To ensure optimal assembly force, the impaction should be standardized, e.g., by using an appropriate surgical instrument.

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Micro-CT imaging of Thiel-embalmed and iodine-stained human temporal bone for 3D modeling

Journal of Otolaryngology - Head and Neck Surgery ◽

10.1186/s40463-021-00522-0 ◽

2021 ◽

Vol 50 (1) ◽

Author(s):

Sebastian Halm ◽

David Haberthür ◽

Elisabeth Eppler ◽

Valentin Djonov ◽

Andreas Arnold

Keyword(s):

Soft Tissue ◽

Temporal Bone ◽

Middle Ear ◽

3D Modeling ◽

Soft Tissues ◽

Ct Imaging ◽

Micro Ct ◽

Data Set ◽

Iodine Staining ◽

Tissue Structures

Abstract Introduction This pilot study explores whether a human Thiel-embalmed temporal bone is suitable for generating an accurate and complete data set with micro-computed tomography (micro-CT) and whether solid iodine-staining improves visualization and facilitates segmentation of middle ear structures. Methods A temporal bone was used to verify the accuracy of the imaging by first digitally measuring the stapes on the tomography images and then physically under the microscope after removal from the temporal bone. All measurements were compared with literature values. The contralateral temporal bone was used to evaluate segmentation and three-dimensional (3D) modeling after iodine staining and micro-CT scanning. Results The digital and physical stapes measurements differed by 0.01–0.17 mm or 1–19%, respectively, but correlated well with the literature values. Soft tissue structures were visible in the unstained scan. However, iodine staining increased the contrast-to-noise ratio by a factor of 3.7 on average. The 3D model depicts all ossicles and soft tissue structures in detail, including the chorda tympani, which was not visible in the unstained scan. Conclusions Micro-CT imaging of a Thiel-embalmed temporal bone accurately represented the entire anatomy. Iodine staining considerably increased the contrast of soft tissues, simplified segmentation and enabled detailed 3D modeling of the middle ear.

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Principal component analysis of knee kinematics and kinetics after anterior cruciate ligament reconstruction

Gait & Posture ◽

10.1016/j.gaitpost.2012.06.003 ◽

2012 ◽

Vol 36 (3) ◽

pp. 609-613 ◽

Cited By ~ 17

Author(s):

Brooke A. Sanford ◽

Audrey R. Zucker-Levin ◽

John L. Williams ◽

William M. Mihalko ◽

Eddie L. Jacobs

Keyword(s):

Principal Component Analysis ◽

Anterior Cruciate Ligament ◽

Anterior Cruciate Ligament Reconstruction ◽

Ligament Reconstruction ◽

Cruciate Ligament ◽

Knee Kinematics ◽

Principal Component ◽

Cruciate Ligament Reconstruction ◽

Anterior Cruciate ◽

Kinematics And Kinetics

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Bioprinted Nanoparticles for Tissue Engineering Applications

ASME 2009 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2009-206760 ◽

2009 ◽

Author(s):

Kivilcim Buyukhatipoglu ◽

Robert Chang ◽

Wei Sun ◽

Alisa Morss Clyne

Keyword(s):

Tissue Engineering ◽

Tissue Growth ◽

Bioactive Components ◽

Engineering Applications ◽

Tissue Properties ◽

Native Tissue ◽

3D Architecture

Tissue engineering may require precise patterning of cells and bioactive components to recreate the complex, 3D architecture of native tissue. However, it is difficult to image and track cells and bioactive factors once they are incorporated into the tissue engineered construct. These bioactive factors and cells may also need to be moved during tissue growth in vitro or after implantation in vivo to achieve the desired tissue properties, or they may need to be removed entirely prior to implantation for biosafety concerns.

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