@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} } @article{WeberDullienGrifkaetal., author = {Weber, Tim and Dullien, Silvia and Grifka, Joachim and Renkawitz, Tobias and Dendorfer, Sebastian}, title = {Validation of a Motion Capture Laboratory and a new marker-placement protcol for clinical applications}, series = {Gait \& Posture}, volume = {38}, journal = {Gait \& Posture}, number = {Suppl. 1}, doi = {10.1016/j.gaitpost.2013.07.229}, pages = {113 -- 114}, language = {en} } @inproceedings{WeberDendorferDullienetal., author = {Weber, Tim A. and Dendorfer, Sebastian and Dullien, Silvia and Grifka, Joachim and Verkerke, Gijsbertus Jacob and Renkawitz, Tobias}, title = {Measuring functional outcome after total hip replacement with subject-specific hip joint loading}, series = {Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine}, volume = {226}, booktitle = {Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine}, number = {12}, doi = {10.1177/0954411912447728}, pages = {939 -- 946}, abstract = {Total hip replacement is an often-performed orthopedic surgical procedure; the amount of procedures undertaken will increase since our life expectancy is growing. In order to optimize function, hip biomechanics should be restored to as near normal as possible. The goal of this pilot study was to determine whether or not it is feasible to compute the vectorial hip reaction force pathways on the head of the prosthesis and the force angles relative to the cup of the prosthesis that occur during gait in total hip replacement patients, serving as an objective measurement of the functional outcome following hip replacement. A three-dimensional gait analysis, measuring ground reaction forces and kinematics, was performed. The data retrieved from the gait analysis was used as the input for the musculoskeletal model to compute vectorial joint reaction forces for data processing. To evaluate the position and orientation of the joint reaction forces, the force path, as well as the force angles for the operated and non-operated joint, has been calculated during the stance phase of the specific leg. The force path for subject 2 on the non-operated side is only located in the posterior-lateral quarter, as is the force path for subject 1. In contrast to this subject, the force path for subject 2 at the operated hip joint can be found only within the anterior quarter of the head of the implant, where it is nearly equally distributed in the medio-lateral half of the prosthesis head. The force-inclination angles on the cup of subject 1, with respect to the plane of the socket face, indicates that the force vector is mainly positioned in the same quadrant when compared with subject 2 (in a cup-fixed coordinate system). The force-anteversion angle behaves similarly to the force-inclination angle, even when the effects are not as pronounced. The proposed methods in this article are aiming to define two functional outcomes of total hip replacement that are related to wear and rim loading. It is accepted that wear is not only a function of time, but a function of use. Owing to the methods listed in this article, we are able to determine a) the applied force and b) the sliding distance (force pathway) in a subject-specific manner. The computed hip-reaction force angles and the distance to the rim cup are a measurement for cup or rim loading, and occurs in the so-called safe-zones. This method may well give us insight into the biomechanical situation during gait, after receiving total hip replacement, that we need to fully understand the mechanisms acting on a hip joint and to prove a possible increase of functional outcome after receiving total hip replacement.}, subject = {H{\"u}ftgelenkprothese}, language = {en} } @article{RenkawitzWeberDullienetal., author = {Renkawitz, Tobias and Weber, Tim A. and Dullien, Silvia and Woerner, Michael and Dendorfer, Sebastian and Grifka, Joachim and Weber, Markus}, title = {Leg length and offset differences above 5 mm after total hip arthroplasty are associated with altered gait kinematics}, series = {Gait \& Posture}, volume = {vol. 49}, journal = {Gait \& Posture}, doi = {10.1016/j.gaitpost.2016.07.011}, pages = {196 -- 201}, abstract = {We aimed to investigate the relationship between postoperative leg length/offset (LL/OS) reconstruction and gait performance after total hip arthroplasty (THA). In the course of a prospective randomized controlled trial, 60 patients with unilateral hip arthrosis received cementless THA through a minimally-invasive anterolateral surgical approach. One year post-operatively, LL and global OS restoration were analyzed and compared to the contralateral hip on AP pelvic radiographs. The combined postoperative limb length/OS reconstruction of the operated hip was categorized as restored (within 5 mm) or non-restored (more than 5 mm reduction or more than 5 mm increment). The acetabular component inclination, anteversion and femoral component anteversion were evaluated using CT scans of the pelvis and the femur. 3D gait analysis of the lower extremity and patient related outcome measures (HHS, HOOS, EQ-5D) were obtained pre-operatively, six months and twelve months post-operatively by an observer blinded to radiographic results. Component position of cup and stem was comparable between the restored and non-restored group. Combined LL and OS restoration within 5 mm resulted in higher Froude number (p < 0.001), normalized walking speed (p < 0.001) and hip range-of-motion (ROM) (p = 0.004) during gait twelve months postoperatively, whereas gait symmetry was comparable regardless of LL and OS reconstruction at both examinations. Clinical scores did not show any relevant association between the accuracy of LL or OS reconstruction and gait six/twelve months after THA. In summary, postoperative LL/OS discrepancies larger than 5 mm relate to unphysiological gait kinematics within the first year after THA. DRKS00000739, German Clinical Trials Register.}, language = {en} } @misc{LautenschlaegerLeisDendorferetal., author = {Lautenschl{\"a}ger, Toni and Leis, Alexander and Dendorfer, Sebastian and Palm, Christoph and Schreiner, Rupert and Langer, Christoph and Prommesberger, Christian and Ɓawrowski, Robert Damian and Dams, Florian and Bornmann, Benjamin and Navitski, Aliaksandr and Serbun, Pavel and M{\"u}ller, G{\"u}nter and Liebetruth, Thomas and Kohlert, Dieter and Pernsteiner, Jochen and Schreier, Franz and Heerklotz, Sabrina and Heerklotz, Allwin and Boos, Alexander and Herwald, Dominik and Monkman, Gareth J. and Treiber, Daniel and Mayer, Matthias and H{\"o}rner, Eva and Bentz, Alexander and Shamonin (Chamonine), Mikhail and Johansen, S{\o}ren Peter and Reichel, Marco and Stoll, Andrea and Briem, Ulrich and Dullien, Silvia and Renkawitz, Tobias and Weber, Tim and Dendorfer, Sebastian and Grifka, Joachim and Penzkofer, Rainer and Barnsteiner, K. and Jovanovik, M. and Wernecke, P. and V{\"o}gele, A. and Bachmann, T. and Pl{\"o}tz, Martin and Schliekmann, Claus and Wels, Harald and Helmberger, Paul and Kaspar, M. and H{\"o}nicka, M. and Schrammel, Siegfried and Enser, Markus and Schmidmeier, Monika and Schroll-Decker, Irmgard and Haug, Sonja and Gelfert, Verena and Vernim, Matthias}, title = {Forschungsbericht 2012}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, doi = {10.35096/othr/pub-783}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-7834}, pages = {64}, language = {de} } @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{WeberStezowskiDullienetal., author = {Weber, Tim and Stezowski, P. and Dullien, Silvia and Putzer, Michael and Dendorfer, Sebastian}, title = {Eine biomechanische Bewertung verschiedener Belastungsszenarien nach Implantierung einer H{\"u}ft-Totalendoprothese}, series = {GAMMA Workshop, Hannover, 2012}, booktitle = {GAMMA Workshop, Hannover, 2012}, 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{WeberDullienPutzeretal., author = {Weber, Tim and Dullien, Silvia and Putzer, Michael and Dendorfer, Sebastian and Renkawitz, Tobias}, title = {Biomechanical outcome after computer-assisted vs. conventional THR - study concept and preliminary gait analysis results}, series = {GAMMA Workshop, Hannover, 2012}, booktitle = {GAMMA Workshop, Hannover, 2012}, language = {en} }