TY  - JOUR
A1  - Hackl, Michael
A1  - Buess, Eduard
A1  - Kammerlohr, Sandra
A1  - Nacov, Julia
A1  - Staat, Manfred
A1  - Leschinger, Tim
A1  - Müller, Lars P.
A1  - Wegmann, Kilian
T1  - A "comma sign"-directed subscapularis repair in anterosuperior rotator cuff tears yields biomechanical advantages in a cadaveric model
JF  - The american journal of sports medicine
N2  - Background:
Additional stabilization of the “comma sign” in anterosuperior rotator cuff repair has been proposed to provide biomechanical benefits regarding stability of the repair.
Purpose:
This in vitro investigation aimed to investigate the influence of a comma sign–directed reconstruction technique for anterosuperior rotator cuff tears on the primary stability of the subscapularis tendon repair.
Study Design:
Controlled laboratory study.
Methods:
A total of 18 fresh-frozen cadaveric shoulders were used in this study. Anterosuperior rotator cuff tears (complete full-thickness tear of the supraspinatus and subscapularis tendons) were created, and supraspinatus repair was performed with a standard suture bridge technique. The subscapularis was repaired with either a (1) single-row or (2) comma sign technique. A high-resolution 3D camera system was used to analyze 3-mm and 5-mm gap formation at the subscapularis tendon-bone interface upon incremental cyclic loading. Moreover, the ultimate failure load of the repair was recorded. A Mann-Whitney test was used to assess significant differences between the 2 groups.
Results:
The comma sign repair withstood significantly more loading cycles than the single-row repair until 3-mm and 5-mm gap formation occurred (P≤ .047). The ultimate failure load did not reveal any significant differences when the 2 techniques were compared (P = .596).
Conclusion:
The results of this study show that additional stabilization of the comma sign enhanced the primary stability of subscapularis tendon repair in anterosuperior rotator cuff tears. Although this stabilization did not seem to influence the ultimate failure load, it effectively decreased the micromotion at the tendon-bone interface during cyclic loading.
Clinical Relevance:
The proposed technique for stabilization of the comma sign has shown superior biomechanical properties in comparison with a single-row repair and might thus improve tendon healing. Further clinical research will be necessary to determine its influence on the functional outcome.
Y1  - 2021
U6  - http://dx.doi.org/10.1177/03635465211031506
SN  - 1552-3365
SN  - 0363-5465
VL  - 49
IS  - 12
SP  - 3212
EP  - 3217
PB  - Sage
CY  - London
ER  - 
TY  - CHAP
A1  - Duong, Minh Tuan
A1  - Jung, Alexander
A1  - Frotscher, Ralf
A1  - Staat, Manfred
ED  - Papadrakakis, M.
T1  - A 3D electromechanical FEM-based model for cardiac tissue
T2  - ECCOMAS Congress 2016, VII European Congress on Computational Methods in Applied Sciences and Engineering. Crete Island, Greece, 5–10 June 2016
Y1  - 2016
N1  - revised after the conference
P11367
ER  - 
TY  - CHAP
A1  - Bhattarai, Aroj
A1  - Frotscher, Ralf
A1  - Sora, M.-C.
A1  - Staat, Manfred
ED  - Onate, E.
T1  - A 3D finite element model of the female pelvic floor for the reconstruction of urinary incontinence
T2  - 11th World Congress on Computational Mechanics (WCCM XI) ; 5th European Conference on Computational Mechanics (ECCM V) ; 6th European Conference on Computational Fluid Dynamics (ECFD VI) ; July 20-25, 2014, Barcelona
Y1  - 2014
SP  - 1
EP  - 12
ER  - 
TY  - JOUR
A1  - Bhattarai, Aroj
A1  - Staat, Manfred
T1  - A computational study of organ relocation after laparoscopic pectopexy to repair posthysterectomy vaginal vault prolapse
JF  - Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization
Y1  - 2019
U6  - http://dx.doi.org/10.1080/21681163.2019.1670095
SN  - 2168-1171
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - CHAP
A1  - Duong, Minh Tuan
A1  - Staat, Manfred
ED  - Onate, E.
T1  - A face-based smoothed finite element method for hyperelastic models and tissue growth
T2  - 11th World Congress on Computational Mechanics (WCCM XI) ; 5th European Conference on Computational Mechanics (ECCM V) ; 6th European Conference on Computational Fluid Dynamics (ECFD VI) ; July 20-25, 2014, Barcelona
Y1  - 2014
SP  - 1
EP  - 12
ER  - 
TY  - JOUR
A1  - Topçu, Murat
A1  - Madabhushi, Gopal S.P.
A1  - Staat, Manfred
T1  - A generalized shear-lag theory for elastic stress transfer between matrix and fibres having a variable radius
JF  - International Journal of Solids and Structures
N2  - A generalized shear-lag theory for fibres with variable radius is developed to analyse elastic fibre/matrix stress transfer. The theory accounts for the reinforcement of biological composites, such as soft tissue and bone tissue, as well as for the reinforcement of technical composite materials, such as fibre-reinforced polymers (FRP). The original shear-lag theory proposed by Cox in 1952 is generalized for fibres with variable radius and with symmetric and asymmetric ends. Analytical solutions are derived for the distribution of axial and interfacial shear stress in cylindrical and elliptical fibres, as well as conical and paraboloidal fibres with asymmetric ends. Additionally, the distribution of axial and interfacial shear stress for conical and paraboloidal fibres with symmetric ends are numerically predicted. The results are compared with solutions from axisymmetric finite element models. A parameter study is performed, to investigate the suitability of alternative fibre geometries for use in FRP.
KW  - Natural fibres
KW  - Polymer-matrix composites
KW  - Biocomposites
KW  - Stress concentrations
KW  - Finite element analysis
Y1  - 2022
U6  - http://dx.doi.org/10.1016/j.ijsolstr.2022.111464
SN  - 0020-7683
VL  - 239–240
IS  - Art. No. 111464
PB  - Elsevier
CY  - New York, NY
ER  - 
TY  - JOUR
A1  - Gossmann, Matthias
A1  - Thomas, Ulrich
A1  - Horváth, András
A1  - Dragicevic, Elena
A1  - Stoelzle-Feix, Sonja
A1  - Jung, Alexander
A1  - Raman, Aravind Hariharan
A1  - Staat, Manfred
A1  - Linder, Peter
T1  - A higher-throughput approach to investigate cardiac contractility in vitro under physiological mechanical conditions
JF  - Journal of Pharmacological and Toxicological Methods
Y1  - 2020
U6  - http://dx.doi.org/10.1016/j.vascn.2020.106843
VL  - 105
IS  - Article 106843
PB  - Elsevier
CY  - New York, NY
ER  - 
TY  - JOUR
A1  - Nguyen, N.-H.
A1  - Raatschen, Hans-Jürgen
A1  - Staat, Manfred
T1  - A hyperelastic model of biological tissue materials in tubular organs
Y1  - 2010
N1  - ECCM 2010, IV European Conference on Computational Mechanics, Paris, France, May 16-21, 2010.
SP  - 1
EP  - 12
ER  - 
TY  - CHAP
A1  - Tran, Ngoc Trinh
A1  - Staat, Manfred
A1  - Stavroulakis, G. E.
ED  - Onate, E.
T1  - A multicriteria method for truss optimization
T2  - 11th World Congress on Computational Mechanics (WCCM XI) ; 5th European Conference on Computational Mechanics (ECCM V) ; 6th European Conference on Computational Fluid Dynamics (ECFD VI) ; July 20-25, 2014, Barcelona
Y1  - 2014
SP  - 1
EP  - 12
ER  - 
TY  - JOUR
A1  - Leschinger, Tim
A1  - Birgel, Stefan
A1  - Hackl, Michael
A1  - Staat, Manfred
A1  - Müller, Lars Peter
A1  - Wegmann, Kilian
T1  - A musculoskeletal shoulder simulation of moment arms and joint reaction forces after medialization of the supraspinatus footprint in rotator cuff repair
JF  - Computer Methods in Biomechanics and Biomedical Engineering
Y1  - 2019
U6  - http://dx.doi.org/10.1080/10255842.2019.1572749
IS  - Early view
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - JOUR
A1  - Linder, Peter
A1  - Beckler, Matthias
A1  - Doerr, Leo
A1  - Stoelzle-Feix, Sonja
A1  - Fertig, Niels
A1  - Jung, Alexander
A1  - Staat, Manfred
A1  - Gossmann, Matthias
T1  - A new in vitro tool to investigate cardiac contractility under physiological mechanical conditions
JF  - Journal of Pharmacological and Toxicological Methods
Y1  - 2019
U6  - http://dx.doi.org/10.1016/j.vascn.2019.05.162
SN  - 1056-8719
VL  - 99
IS  - Article number 106595
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Grottke, O.
A1  - Braunschweig, T.
A1  - Philippen, B.
A1  - Gatzweiler, Karl-Heinz
A1  - Gronloh, N.
A1  - Staat, Manfred
A1  - Rossaint, R.
A1  - Tolba, R.
T1  - A New Model for Blunt Liver Injuries in the Swine
JF  - European Surgical Research. 44 (2010), H. 2
Y1  - 2010
SN  - 1421-9921
SP  - 65
EP  - 73
ER  - 
TY  - JOUR
A1  - Pham, Phu Tinh
A1  - Vu, Khoi Duc
A1  - Tran, Thanh Ngoc
A1  - Staat, Manfred
T1  - A primal-dual algorithm for shakedown analysis of elastic-plastic bounded linearly kinematic hardening bodies
Y1  - 2010
N1  - ECCM 2010, IV European Conference on Computational Mechanics, Paris, France, May 16-21, 2010.
SP  - 1
EP  - 7
ER  - 
TY  - CHAP
A1  - Tran, Thanh Ngoc
A1  - Staat, Manfred
ED  - Eberhardsteiner, J.
T1  - A primal-dual shakedown analysis of 3D structures using the face-based smoothed finite element method
T2  - Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012)
Y1  - 2012
N1  - 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012
ER  - 
TY  - CHAP
A1  - Pham, Phu Tinh
A1  - Staat, Manfred
T1  - A simplification for shakedown analysis of hardening structures
T2  - Conference proceedings of the YIC GACM 2015 : 3rd ECCOMAS Young Investigators Conference and 6th GACM Colloquium on Computational Mechanics , Aachen , Germany, 20.07.2015 - 23.07.2015 / ed.: Stefanie Elgeti ; Jaan-Willem Simon
Y1  - 2015
SP  - 1
EP  - 4
PB  - RWTH Aachen University
CY  - Aachen
ER  - 
TY  - JOUR
A1  - Kühn, Raoul-Roman
A1  - Haugner, Werner
A1  - Staat, Manfred
A1  - Sponagel, Stefan
T1  - A Two Phase Mixture Model based on Bone Observation
N2  - An optimization method is developed to describe the mechanical behaviour of the human cancellous bone. The method is based on a mixture theory. A careful observation of the behaviour of the bone material leads to the hypothesis that the bone density is controlled by the principal stress trajectories (Wolff’s law). The basic idea of the developed method is the coupling of a scalar value via an eigenvalue problem to the principal stress trajectories. On the one hand this theory will permit a prediction of the reaction of the biological bone structure after the implantation of a prosthesis, on the other hand it may be useful in engineering optimization problems. An analytical example shows its efficiency.
KW  - Knochen
KW  - Knochenbildung
KW  - Knochenchirugie
KW  - Strukturanalyse
KW  - Schwammknochen
KW  - Knochendichte
KW  - Wolffsches Gesetz
KW  - bone structure
KW  - bone density
KW  - Wolff's Law
KW  - cancellous bone
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Vu, Duc-Khoi
T1  - An Algorithm for Shakedown Analysis for Materials with Temperature Dependent Yield Stress
JF  - Proceedings in Applied Mathematics and Mechanics (PAMM). 4 (2004), H. 1
Y1  - 2004
SN  - 1617-7061
SP  - 231
EP  - 233
ER  - 
TY  - JOUR
A1  - Vu, Duc-Khoi
A1  - Staat, Manfred
T1  - An algorithm for shakedown analysis of structure with temperature dependent yield stress
N2  - This work is an attempt to answer the question: How to use convex programming in shakedown analysis of structures made of materials with temperature-dependent properties. Based on recently established shakedown theorems and formulations, a dual relationship between upper and lower bounds of the shakedown limit load is found, an algorithmfor shakedown analysis is proposed. While the original problem is neither convex nor concave, the algorithm presented here has the advantage of employing convex programming tools.
KW  - Einspielen <Werkstoff>
KW  - Temperaturabhängigkeit
KW  - Fließgrenze
KW  - Shakedown
KW  - shakedown analysis
KW  - yield stress
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Tran, Thanh Ngoc
A1  - Staat, Manfred
T1  - An Edge-Based Smoothed Finite Element Method for Primal-Dual Shakedown Analysis of Structures Under Uncertainties
JF  - Limit State of Materials and Structures : Direct Methods 2. Saxcé, Géry de (Hrsg.)
Y1  - 2013
SN  - 978-94-007-5424-9
SP  - 89
EP  - 102
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - CHAP
A1  - Frotscher, Ralf
A1  - Staat, Manfred
T1  - An electromechanical model for cardiac tissue constructs
T2  - Conference proceedings of the YIC GACM 2015 : 3rd ECCOMAS Young Investigators Conference and 6th GACM Colloquium on Computational Mechanics , Aachen, 20.07.2015 - 23.07.2015  / ed.: Stefanie Elgeti ; Jaan-Willem Simon
Y1  - 2015
SP  - 1
EP  - 4
PB  - RWTH Aachen University
CY  - Aachen
ER  -