@article{LazarevRyabokonHalleretal., author = {Lazarev, I.A. and Ryabokon, P.V. and Haller, M. and Dendorfer, Sebastian}, title = {Effect of the fractured calcaneus's peripheral fragment displacement on the triceps surae function}, series = {ЖУРНАЛ «ТРАВМА» Ukrainian Trauma Journal}, volume = {2, TOM 16}, journal = {ЖУРНАЛ «ТРАВМА» Ukrainian Trauma Journal}, language = {en} } @inproceedings{AurbachWagnerSuessetal., author = {Aurbach, Maximilian and Wagner, Kilian and S{\"u}ß, Franz and Dendorfer, Sebastian}, title = {Implementation and Validation of Human Kinematics Measured Using IMUs for Musculoskeletal Simulations by the Evaluation of Joint Reaction Forces}, series = {CMBEBIH 2017, Proceedings of the International Conference on Medical and Biological Engineering 2017, Sarajevo, Bosnia and Herzegovina}, volume = {Vol. 62}, booktitle = {CMBEBIH 2017, Proceedings of the International Conference on Medical and Biological Engineering 2017, Sarajevo, Bosnia and Herzegovina}, editor = {Badnjevic, Almir}, publisher = {Springer}, address = {Singapore}, doi = {10.1007/978-981-10-4166-2_31}, pages = {205 -- 211}, abstract = {The gold standard for the analysis of human kinematics and kinetics is a camera-based motion capture system in combination with force measurement platforms. Alternatively, inertial measurement units can be utilized to obtain human kinematics, while ground reaction forces are computed from full body dynamics. This setup represents a system independent from the spatial confinement of a gait laboratory. The aim of this study is the comparison of the two methods by the investigation of lower limb kinematics and the resulting joint reaction forces within the ankle-, knee- and hip joints. For this purpose, human motion during gait was captured simultaneously by both measurement techniques. 13 trials from 8 different test subjects were evaluated in total. IMU data was processed with a quaternion based Kalman Filter. The data sets were implemented into a musculoskeletal simulation program in order to drive a virtual human body model. Each sensor was aligned to the gravitational and magnetic field vectors of the earth. The angles of flexions, extensions and rotations were analyzed to determine kinematic differences. Joint reaction forces defined kinetic dissimilarities. The overall kinematic differences of both models yielded root mean square errors of 7.62°, 6.02°, 4.95°, 2.79°, 2.38° and 3.56° for ankle flexion, subtalar eversion, knee flexion, hip external rotation, hip abduction and hip flexion, respectively. The proximo-distal differences in force peaks between the models yielded overall for the ankle, 57.33 \%Bodyweight(BW) ± 46.86 \%BW (16.66 \%(Maximum peak to peak) ± 13.62 \%) for the knee 37.09 \%BW ± 29.33 \%BW (17.65 \% ± 15.44 \%) and 32.03 \%BW ± 24.33 \%BW (15.6 \% ± 12.54 \%) for the hip. The overall outcome of this work investigated an approach independent of the common setup of the gait laboratory, thus enabling a cheaper and more flexible technology as an alternative. However, kinematic and thus kinetic differences remain rather large. Future work aims to improve the contact criterion for the calculation of the ground reaction forces and the implementation of a full-body calibration algorithm for the IMU system in order to counteract magnetic field disturbances.}, subject = {Bewegungsapparat}, language = {en} } @article{DePieriAtzoriFergusonetal., author = {De Pieri, Enrico and Atzori, Federica and Ferguson, Stephen J. and Dendorfer, Sebastian and Leunig, Michael and Aepli, Martin}, title = {Contact force path in total hip arthroplasty: effect of cup medialisation in a whole-body simulation}, series = {HIP International}, volume = {31}, journal = {HIP International}, number = {5}, publisher = {Sage}, doi = {10.1177/1120700020917321}, pages = {624 -- 631}, abstract = {Background: Cup medialisation down to the true acetabular floor in total hip arthroplasty with a compensatory femoral offset increase seems to be mechanically advantageous for the abductor muscles due to the relocation of the lever arms (body weight lever arm decreased, abductor lever arm increased). However, limited information is currently available about the effects of this reconstruction type at the head cup interface, compared to an anatomical reconstruction that maintains the natural lever arms. Through a whole-body simulation analysis, we compared medialised versus anatomical reconstruction in THA to analyse the effects on: (1) contact force magnitude at the head cup interface; (2) contact force path in the cup; and (3) abductor activity. Methods: Musculoskeletal simulations were performed to calculate the above-mentioned parameters using inverse dynamics analysis. The differences between the virtually implanted THAs were calculated to compare the medialised versus anatomical reconstruction. Results: Cup medialisation with compensatory femoral offset increase led to: (1) a reduction in contact force magnitude at the head cup interface up to 6.6\%; (2) a similar contact force path in the cup in terms of sliding distance and aspect ratio; and (3) a reduction in abductor activity up to 17.2\% (gluteus medius). Conclusions: In our opinion, these potential biomechanical gains do not generally justify a fully medialised reconstruction, especially in younger patients that are more likely to undergo revision surgery in their lifetime. Cup medialisation should be performed until sufficient press fit and bony coverage of a properly sized and oriented cup can be achieved.}, subject = {H{\"u}ftgelenkprothese}, language = {en} } @misc{OPUS4-330, title = {Medicine Meets Engineering: Proceedings of the 2nd Conference on Applied Biomechanics Regensburg}, editor = {Hammer, Joachim and Nerlich, Michael and Dendorfer, Sebastian}, edition = {1. Aufl.}, publisher = {IOS Press, US}, isbn = {978-1586038281}, pages = {X, 247}, abstract = {Biomedical Engineering is defined as the science that integrates medical and engineering sciences to improve diagnosis and treatment of patients. Only by this integration progress can be achieved. Both medical and engineering sciences comprise a huge diversity in topics, so it is imaginable that Biomedical Engineering, combining these two science areas, is even more huge. Thanks to this megadisciplinary approach many breakthroughs can be achieved. More and more research groups realize this and start new research projects, which results in a rapid increase in knowledge in Biomedical Engineering. This will only benefit the main goal of Biomedical Engineering; improving diagnosis and treatment of patients when it is spread and applied. The 2nd Regensburg Applied Biomechanics conference is special in that it realized both the distribution of new knowledge and the essential integration of medical and engineering specialists. The conference dealt with the latest results in applied biomechanics, ranging from fundamental bone strength properties via bone remodeling phenomena to new implants that replace lost human functions. Also new research areas like robot surgery and tissue engineering were discussed.}, subject = {Biomechanik}, language = {en} } @article{RenkawitzDendorfer, author = {Renkawitz, Tobias and Dendorfer, Sebastian}, title = {Orthopedic navigation technology and biomechanical evaluation for total hip replacement}, series = {Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine}, volume = {226}, journal = {Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine}, number = {12}, doi = {10.1177/0954411912458746}, pages = {897 -- 898}, subject = {H{\"u}ftgelenkprothese}, language = {en} } @inproceedings{WeberStezowskiDullienetal., author = {Weber, Tim and Stezowski, P. and Dullien, Silvia and Dendorfer, Sebastian}, title = {Eine biomechanische Bewertung verschiedener Belastungsszenarios nach der Implantierung einer H{\"u}ft-Totalendoprothese}, series = {89. Jahrestagung der Vereinigung der Bayerischen Chirurgen e.V., 25. - 27. Juli 2012, Regensburg}, booktitle = {89. Jahrestagung der Vereinigung der Bayerischen Chirurgen e.V., 25. - 27. Juli 2012, Regensburg}, language = {de} } @inproceedings{WeberDendorferRenkawitzetal., author = {Weber, Tim and Dendorfer, Sebastian and Renkawitz, Tobias and Dullien, Silvia and Grifka, Joachim}, title = {Clinical gait analysis combined with musculoskeletal modelling - coding a new generation of evaluation instruments}, series = {Deutsche Gesellschaft f{\"u}r Biomechanik, Murnau, 2011}, booktitle = {Deutsche Gesellschaft f{\"u}r Biomechanik, Murnau, 2011}, language = {en} } @inproceedings{PillingSuessKubowitschetal., author = {Pilling, A. and S{\"u}ß, Franz and Kubowitsch, Simone and Dendorfer, Sebastian}, title = {Experimental workflow for determining psychological stress from physiological biosignals}, series = {Jahrestagung der BIOMEDIZINISCHEN TECHNIK und Dreil{\"a}ndertagung der MEDIZINISCHEN PHYSIK, Dresden, Germany, 2017}, booktitle = {Jahrestagung der BIOMEDIZINISCHEN TECHNIK und Dreil{\"a}ndertagung der MEDIZINISCHEN PHYSIK, Dresden, Germany, 2017}, language = {en} } @article{ZellnerHierlMuelleretal., author = {Zellner, Johannes and Hierl, Katja and Mueller, Michael and Pfeifer, Christian and Berner, Arne and Dienstknecht, Thomas and Krutsch, Werner and Geis, Sebastian and Gehmert, Sebastian and Kujat, Richard and Dendorfer, Sebastian and Prantl, Lukas and Nerlich, Michael and Angele, Peter}, title = {Stem cell-based tissue-engineering for treatment of meniscal tears in the avascular zone}, series = {Journal of Biomedical Materials Research Part B Applied Biomaterials}, volume = {101}, journal = {Journal of Biomedical Materials Research Part B Applied Biomaterials}, number = {7}, editor = {Gilbert, Jeremy}, doi = {10.1002/jbm.b.32922}, pages = {1133 -- 1142}, abstract = {Meniscal tears in the avascular zone have a poor self-healing potential, however partial meniscectomy predisposes the knee for early osteoarthritis. Tissue engineering with mesenchymal stem cells and a hyaluronan collagen based scaffold is a promising approach to repair meniscal tears in the avascular zone. 4 mm longitudinal meniscal tears in the avascular zone of lateral menisci of New Zealand White Rabbits were performed. The defect was left empty, sutured with a 5-0 suture or filled with a hyaluronan/collagen composite matrix without cells, with platelet rich plasma or with autologous mesenchymal stem cells. Matrices with stem cells were in part precultured in chondrogenic medium for 14 days prior to the implantation. Menisci were harvested at 6 and 12 weeks. The developed repair tissue was analyzed macroscopically, histologically and biomechanically. Untreated defects, defects treated with suture alone, with cell-free or with platelet rich plasma seeded implants showed a muted fibrous healing response. The implantation of stem cell-matrix constructs initiated fibrocartilage-like repair tissue, with better integration and biomechanical properties in the precultured stem cell-matrix group. A hyaluronan-collagen based composite scaffold seeded with mesenchymal stem cells is more effective in the repair avascular meniscal tear with stable meniscus-like tissue and to restore the native meniscus.}, subject = {Meniskusschaden}, language = {en} } @inproceedings{WeberDendorferGrifkaetal., author = {Weber, Tim and Dendorfer, Sebastian and Grifka, Joachim and Weber, Markus and W{\"o}rner, Michael and Dullien, Silvia and Verkerke, Gijsbertus Jacob and Renkawitz, Tobias}, title = {Verbessert die computerassistierte Femur First Operationstechnik f{\"u}r die H{\"u}ftendoprothetik den muskuloskelettalen Lastfall auf das H{\"u}ftgelenk?}, series = {DKOU 2015, Deutscher Kongress f{\"u}r Orthop{\"a}die und Unfallchirurgie 2015}, booktitle = {DKOU 2015, Deutscher Kongress f{\"u}r Orthop{\"a}die und Unfallchirurgie 2015}, language = {de} }