ABSTRACT
INTRODUCTION AND HYPOTHESIS: The female pelvic floor is a complex network of ligaments and muscles whose mechanical properties have not been completely understood. The goal of this study is to understand the biomechanical properties of the pelvic floor tissues of young women and the impact of aging. METHODS: Biomechanical uniaxial tension tests were performed on pelvic floor tissues (ligaments and organs) of six young female cadavers (average 29 years old). Results have been analyzed in order to define the characteristics of the mechanical properties of young pelvic soft tissues. Results have been compared with those in the literature in order to understand the similarities and discrepancies between young and old patients. RESULTS: Damageable, nonlinear elastic biomechanical behavior is observed. The variation in stiffness among the pelvic floor organs could be shown. Ligaments and the vaginal wall are the most rigid organs, whereas the rectum and bladder tend to be less rigid (approximately two times less rigid for small deformations and three times less rigid for large deformations). This study shows that ligaments and the vaginal wall of young women have similar mechanical behavior while those of older women differ. Furthermore, young women's tissues differ slightly from older women's tissues. CONCLUSIONS: Results show that aging and possibly diverse "trauma" have an impact on modifying the mechanical behavior of pelvic floor tissues. Over time pelvic floor ligaments and vaginal tissues will differentiate and acquire different mechanical behavior, as seen within the literature in older cadavers.
Subject(s)
Aging/physiology , Broad Ligament/physiology , Rectum/physiology , Round Ligament of Uterus/physiology , Urinary Bladder/physiology , Vagina/physiology , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Biomechanical Phenomena , Cadaver , Elasticity , Female , Humans , Middle Aged , Stress, Mechanical , Young AdultABSTRACT
BACKGROUND: A robotic system for the implantation of a total hip arthroplasty (THA) is currently under development. One of the goals of this system is non-invasive patient fixation, aiding the robotic system by an infrared tracking system. To determine the extent of fixation that can be achieved by non-invasive methods, an in vitro study was performed. METHODS: In cadaver testing, different non-invasive fixation methods (Arthrex leg holder with tourniquet mechanism; arthroscopic leg holder with disposable foam inserts; gynaecological leg holder; Goepel knee crutch) were evaluated under load in different directions. RESULTS: Deviation was measured in the range 0.33-18.1 mm with up to 20 N load. The testing showed the pneumatic leg holder system to provide the highest stability, followed by an arthroscopic leg holder system with foam inserts. CONCLUSIONS: Use of a leg holder with foam inserts produced a stability that should enable tracking of the remaining deviation by the navigation system. We will therefore use this method in our future development of the robotic milling tool.
Subject(s)
Arthroplasty, Replacement, Hip/instrumentation , Arthroplasty, Replacement, Hip/methods , Arthroscopy/methods , Robotics , Aged , Cadaver , Equipment Design , Humans , Infrared Rays , Male , Movement , Posture , Prosthesis Fitting , Surgery, Computer-AssistedABSTRACT
The technical aspects of manual total hip arthroplasty are briefly described. The development, technique and technical problems of previous robotic systems in total hip arthroplasty are described with special details of the Robodoc--System. Recent advances regarding the minimally invasive technique of total-hip implantation and navigation are described. The current development of a robotic assisted system for total hip arthroplasty is presented. This project aims to combine the advantages of minimally invasive techniques and navigational systems with the accuracy that robotic assisted bone milling can provide. The project-name is RomEo (Robotic minimally invasive Endoprosthetics), the main project partners are the Helmut-Schmidt-University/Hamburg and the Department of Trauma and Orthopaedics of the BG Trauma Hospital Hamburg.
Subject(s)
Arthroplasty, Replacement, Hip/methods , Minimally Invasive Surgical Procedures , Robotics , Surgery, Computer-Assisted , Arthroplasty, Replacement, Hip/instrumentation , Arthroplasty, Replacement, Hip/trends , History, 20th Century , Humans , Minimally Invasive Surgical Procedures/trends , Robotics/history , Surgical InstrumentsABSTRACT
Three hundred and seventeen patients with hypopharyngeal tumours presented at Assuit University Hospital and were studied retrospectively with regard to sex and age incidence. Postcricoid tumours form the majority (50.1 per cent) followed by pyriform fossa tumours (26.5 per cent) and finally posterior pharyngeal wall tumours (23.4 per cent). Men form the majority (211 out of 317, i.e. 69.7 per cent). The age incidence shows two peaks at 31-35 years and 56-60 years. The first peak is formed mainly of women while the second peak is formed mainly of men.
