• Deutsch
Login

Open Access

  • Home
  • Search
  • Browse
  • Publish
  • FAQ
  • Dewey Decimal Classification
  • 6 Technik, Medizin, angewandte Wissenschaften
  • 61 Medizin und Gesundheit

617 Chirurgie und verwandte medizinische Fachrichtungen

Refine

Author

  • Dendorfer, Sebastian (19)
  • Renkawitz, Tobias (6)
  • Grifka, Joachim (5)
  • Schratzenstaller, Thomas G. (4)
  • Geith, Markus A. (3)
  • Lenich, Andreas (3)
  • Nerlich, Michael (3)
  • Prantl, Lukas (3)
  • Raptis, Georgios (3)
  • Weber, Markus (3)
+ more

Year of publication

  • 2020 (4)
  • 2019 (3)
  • 2018 (3)
  • 2017 (2)
  • 2015 (4)
  • 2014 (3)
  • 2013 (1)
  • 2012 (4)
  • 2011 (3)
  • 2010 (1)
+ more

Document Type

  • Article (25)
  • conference proceeding (article) (3)
  • Part of a Book (2)
  • conference proceeding (presentation) (2)
  • Book (1)

Language

  • English (32)
  • German (1)

Has Fulltext

  • no (33)

Is part of the Bibliography

  • no (33)

Keywords

  • Hüftgelenkprothese (7)
  • Biomechanik (5)
  • Simulation (5)
  • Biomechanische Analyse (4)
  • Biomechanics (3)
  • Stent (3)
  • Ballondilatation (2)
  • Belastung (2)
  • Biomaterial (2)
  • Computerunterstütztes Verfahren (2)
+ more

Institute

  • Fakultät Maschinenbau (28)
  • Labor Biomechanik - LBM (22)
  • Regensburg Center of Biomedical Engineering - RCBE (19)
  • Fakultät Informatik und Mathematik (5)
  • Labor Medizinprodukte - MD (5)
  • Labor eHealth - eH (3)
  • Regensburg Medical Image Computing - ReMIC (2)
  • Labor Biomaterialien - BMA (1)
  • Regensburg Center of Health Sciences and Technology - RCHST (1)

33 search hits

  • 1 to 10
  • BibTeX
  • CSV
  • RIS
  • XML
  • 10
  • 20
  • 50
  • 100

Sort by

  • Year
  • Year
  • Title
  • Title
  • Author
  • Author
Degradation and bioactivity studies of Mg membranes for dental surgery (2019)
Hornberger, Helga ; Striegl, Birgit ; Trahanofsky, M. ; Kneissl, F. ; Kronseder, Matthias
Bioresorbable materials are under investigation due to their promising properties for applications as implant material. This study is about the degradation and bioactivity behaviour of magnesium foils, which allegorize dental membranes. The degradation behaviour including pitting corrosion during immersion tests can be precisely observed using micro-computed tomography. Using the bioactivity test according to Kokubo, it is shown that magnesium has strong Ca-phosphate layer formation correlated with high degradation. Therefore, magnesium foils appear to hold a great potential for bone implant application.
A Novel Method of Outcome Assessment in Breast Reconstruction Surgery: Comparison of Autologous and Alloplastic Techniques Using Three-Dimensional Surface Imaging (2020)
Hartmann, Robin ; Weiherer, Maximilian ; Schiltz, Daniel ; Seitz, Stephan ; Lotter, Luisa ; Anker, Alexandra ; Palm, Christoph ; Prantl, Lukas ; Brébant, Vanessa
Background Breast reconstruction is an important coping tool for patients undergoing a mastectomy. There are numerous surgical techniques in breast reconstruction surgery (BRS). Regardless of the technique used, creating a symmetric outcome is crucial for patients and plastic surgeons. Three-dimensional surface imaging enables surgeons and patients to assess the outcome’s symmetry in BRS. To discriminate between autologous and alloplastic techniques, we analyzed both techniques using objective optical computerized symmetry analysis. Software was developed that enables clinicians to assess optical breast symmetry using three-dimensional surface imaging. Methods Twenty-seven patients who had undergone autologous (n = 12) or alloplastic (n = 15) BRS received three-dimensional surface imaging. Anthropomorphic data were collected digitally using semiautomatic measurements and automatic measurements. Automatic measurements were taken using the newly developed software. To quantify symmetry, a Symmetry Index is proposed. Results Statistical analysis revealed that there is no dif- ference in the outcome symmetry between the two groups (t test for independent samples; p = 0.48, two-tailed). Conclusion This study’s findings provide a foundation for qualitative symmetry assessment in BRS using automatized digital anthropometry. In the present trial, no difference in the outcomes’ optical symmetry was detected between autologous and alloplastic approaches.
Applications of the Erbium: YAG Laser in Ophthalmology - Cataracta-, Glaukoma-, Eyelid-Surgery and pars plana Vitrectomy (2000)
Höh, H. ; Raptis, Georgios
Recent developments in lasers have provided us the possibility of laser ocular surgery. The xenon, argon, neodymium:YAG and dye lasers have been successfully used in out-patient clinics. The excimer laser has been attracting researchers' interest in the new application of laser to cornea and lens. The erbium:YAG laser emits a 2.94-microns beam that can ablate the transparent ocular tissues such as lenses and corneas. The author has applied this laser to the cornea, lens, vitreous and other ocular tissues. The erbium:YAG laser beam was directed through a 1.5-meter-long, 200-microns-diameter fiberoptic guide. The radiant energy measured about 50 mJ at the end of the probe. The laser was emitted as a 400-microsecond pulse. Freshly enucleated rabbit eyes were used in this study. Laser burns were applied to the tissue surface at various energy settings. At minimal power, the tissues were coagulated by the erbium:YAG laser application. At a power of more than 636-954 mJ/mm2, tissue began to evaporate; the tissue loss was observed under a surgical light microscope. Corneal photoablation, lens ablation, iridotomy, trabeculotomy, cutting of the vitreous and retinal ablation were easily performed. Like the excimer laser, the erbium:YAG laser is a potential tool for ocular surgery.
Standardised handling of hysterectomy specimen in cervical cancer – report of over 900 stage pT1b1- to pT2b-tumors (2000)
Horn, Lars-Christian ; Raptis, Georgios ; Fischer, Uta ; Bilek, Karin
Contact force path in total hip arthroplasty: effect of cup medialisation in a whole-body simulation (2020)
De Pieri, Enrico ; Atzori, Federica ; Ferguson, Stephen J. ; Dendorfer, Sebastian ; Leunig, Michael ; Aepli, Martin
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.
Effect of the fractured calcaneus’s peripheral fragment displacement on the triceps surae function (2015)
Lazarev, I.A. ; Ryabokon, P.V. ; Haller, M. ; Dendorfer, Sebastian
The impact of standard combined anteversion definitions on gait and clinical outcome within one year after total hip arthroplasty (2015)
Weber, Markus ; Weber, Tim A. ; Woerner, Michael ; Craiovan, Benjamin ; Worlicek, Michael ; Winkler, Sebastian ; Grifka, Joachim ; Renkawitz, Tobias
Different target areas within the concept of combined cup and stem anteversion have been published for total hip arthroplasty (THA). We asked whether component positioning according to eight standard combined anteversion rules is associated with (1) more physiological gait patterns, (2) higher improvement of gait variables and (3) better clinical outcome after THA.In a prospective clinical study, 60 patients received cementless THA through an anterolateral MIS approach in a lateral decubitus position. Six weeks postoperatively, implant position was analysed using 3D-CT by an independent external institute. Preoperatively, six and 12 months postoperatively range of motion, normalized walking speed and hip flexion symmetry index were measured using 3D motion-capture gait analysis. Patient-related outcome measures (HHS, HOOS, EQ-5D) were obtained by an observer blinded to 3D-CT results. Eight combined anteversion definitions and Lewinnek's "safe zone" were evaluated regarding their impact on gait patterns and clinical outcome.Combined cup and stem anteversion according to standard combined anteversion definitions as well as cup placement within Lewinnek's "safe zone" did not influence range of motion, normalized walking speed and/or hip flexion symmetry index six and 12 months after THA. Similarly, increase of gait parameters within the first year after THA was comparable between all eight combined anteversion rules. Clinical outcome measures like HHS, HOOS and EQ-5D did not show any benefit for either of the combined anteversion definitions.Standard combined cup and stem anteversion rules do not improve postoperative outcome as measured by gait analysis and clinical scores within one year after THA.
Influence of minimally invasive total hip replacement on hip reaction forces and their orientations (2014)
Weber, Tim ; Al-Munajjed, Amir Andreas ; Verkerke, Gijsbertus Jacob ; Dendorfer, Sebastian ; Renkawitz, Tobias
Minimally invasive surgery (MIS) is becoming increasingly popular. Supporters claim that the main advantages of MIS total hip replacement (THR) are less pain and a faster rehabilitation and recovery. Critics claim that safety and efficacy of MIS are yet to be determined. We focused on a biomechanical comparison between surgical standard and MIS approaches for THR during the early recovery of patients. A validated, parameterized musculoskeletal model was set to perform a squat of a 50th percentile healthy European male. A bilateral motion was chosen to investigate effects on the contralateral side. Surgical approaches were simulated by excluding the incised muscles from the computations. Resulting hip reaction forces and their symmetry and orientation were analyzed. MIS THR seemed less influential on the symmetry index of hip reaction forces between the operated and nonoperated leg when compared to the standard lateral approach. Hip reaction forces at peak loads of the standard transgluteal approach were 24% higher on the contralateral side when compared to MIS approaches. Our results suggest that MIS THR contributes to a greater symmetry of hip reaction forces in absolute value as well as force-orientation following THR.
Musculoskeletal modeling for hip replacement outcome analyses and other applications (2014)
Dendorfer, Sebastian ; Weber, Tim ; Kennedy, O.
The influence of age, shoe type and kicking direction on the severity of head trauma (2014)
Penzkofer, Rainer ; Barnsteiner, K. ; Dendorfer, Sebastian
In the last few years, increasingly kicks to the head were observed as a criminal offense. This study examined the influence of age, shoe type and kicking direction on the severity of head trauma. Male test persons were divided into two groups “Old” and “Young”. Both groups were equipped with light sneakers and combat boots. A standard laboratory crash dummy was used to simulate the victim’s body. First, the dummy’s head, free floating above the ground, was kicked vertically. Second, the dummy’s head was kicked horizontally. Established injury criteria were used to quantify the injury risk. No influence concerning the type of foot wear and no difference between the groups “Old” and “Young” could be found. For all analyses, kicking vertically generally lead to a higher risk for the subject compared to kicking horizontally. In this study, only the integral effect of the kicks could be analyzed. A detailed injury pattern cannot directly be derived from the data. Nevertheless, the presented data show the massive potential of injuries associated with head kicks.
  • 1 to 10

OPUS4 Logo

  • Contact
  • Imprint and Datasecure
  • Sitelinks