Sample records for bone surgical simulation

  1. Good experiences with interactive temporal bone surgical simulator

    DEFF Research Database (Denmark)

    Andersen, Steven A W; Mikkelsen, Peter Trier; Noe, Karsten Ostergaard


    time. In a multilingual user interface the integrated tutor function provides stepwise instructions during drilling through an intuitive, volumetric approach. A censor function draws on metrics derived from the simulator to provide instant and summary feedback for the user. The VES can be downloaded...

  2. 3D Surgical Simulation (United States)

    Cevidanes, Lucia; Tucker, Scott; Styner, Martin; Kim, Hyungmin; Chapuis, Jonas; Reyes, Mauricio; Proffit, William; Turvey, Timothy; Jaskolka, Michael


    This paper discusses the development of methods for computer-aided jaw surgery. Computer-aided jaw surgery allows us to incorporate the high level of precision necessary for transferring virtual plans into the operating room. We also present a complete computer-aided surgery (CAS) system developed in close collaboration with surgeons. Surgery planning and simulation include construction of 3D surface models from Cone-beam CT (CBCT), dynamic cephalometry, semi-automatic mirroring, interactive cutting of bone and bony segment repositioning. A virtual setup can be used to manufacture positioning splints for intra-operative guidance. The system provides further intra-operative assistance with the help of a computer display showing jaw positions and 3D positioning guides updated in real-time during the surgical procedure. The CAS system aids in dealing with complex cases with benefits for the patient, with surgical practice, and for orthodontic finishing. Advanced software tools for diagnosis and treatment planning allow preparation of detailed operative plans, osteotomy repositioning, bone reconstructions, surgical resident training and assessing the difficulties of the surgical procedures prior to the surgery. CAS has the potential to make the elaboration of the surgical plan a more flexible process, increase the level of detail and accuracy of the plan, yield higher operative precision and control, and enhance documentation of cases. Supported by NIDCR DE017727, and DE018962 PMID:20816308

  3. Patient-specific surgical simulation. (United States)

    Soler, Luc; Marescaux, Jacques


    Technological innovations of the twentieth century have provided medicine and surgery with new tools for education and therapy definition. Thus, by combining Medical Imaging and Virtual Reality, patient-specific applications providing preoperative surgical simulation have become possible.

  4. Simulation-based surgical education. (United States)

    Evgeniou, Evgenios; Loizou, Peter


    The reduction in time for training at the workplace has created a challenge for the traditional apprenticeship model of training. Simulation offers the opportunity for repeated practice in a safe and controlled environment, focusing on trainees and tailored to their needs. Recent technological advances have led to the development of various simulators, which have already been introduced in surgical training. The complexity and fidelity of the available simulators vary, therefore depending on our recourses we should select the appropriate simulator for the task or skill we want to teach. Educational theory informs us about the importance of context in professional learning. Simulation should therefore recreate the clinical environment and its complexity. Contemporary approaches to simulation have introduced novel ideas for teaching teamwork, communication skills and professionalism. In order for simulation-based training to be successful, simulators have to be validated appropriately and integrated in a training curriculum. Within a surgical curriculum, trainees should have protected time for simulation-based training, under appropriate supervision. Simulation-based surgical education should allow the appropriate practice of technical skills without ignoring the clinical context and must strike an adequate balance between the simulation environment and simulators. © 2012 The Authors. ANZ Journal of Surgery © 2012 Royal Australasian College of Surgeons.

  5. Surgical consideration for benign bone tumors | Eyesan | Nigerian ...

    African Journals Online (AJOL)

    Background: The surgical management of symptomatic benign bone tumor has been described in various manners in medical literature. However, there are few published reports on the presentation and surgical management of benign bone tumors in black African patients. Objectives: To determine the pattern of ...

  6. Temporal bone dissection simulator for training pediatric otolaryngology surgeons (United States)

    Tabrizi, Pooneh R.; Sang, Hongqiang; Talari, Hadi F.; Preciado, Diego; Monfaredi, Reza; Reilly, Brian; Arikatla, Sreekanth; Enquobahrie, Andinet; Cleary, Kevin


    Cochlear implantation is the standard of care for infants born with severe hearing loss. Current guidelines approve the surgical placement of implants as early as 12 months of age. Implantation at a younger age poses a greater surgical challenge since the underdeveloped mastoid tip, along with thin calvarial bone, creates less room for surgical navigation and can result in increased surgical risk. We have been developing a temporal bone dissection simulator based on actual clinical cases for training otolaryngology fellows in this delicate procedure. The simulator system is based on pre-procedure CT (Computed Tomography) images from pediatric infant cases (<12 months old) at our hospital. The simulator includes: (1) simulation engine to provide the virtual reality of the temporal bone surgery environment, (2) a newly developed haptic interface for holding the surgical drill, (3) an Oculus Rift to provide a microscopic-like view of the temporal bone surgery, and (4) user interface to interact with the simulator through the Oculus Rift and the haptic device. To evaluate the system, we have collected 10 representative CT data sets and segmented the key structures: cochlea, round window, facial nerve, and ossicles. The simulator will present these key structures to the user and warn the user if needed by continuously calculating the distances between the tip of surgical drill and the key structures.

  7. GPU Accelerated Surgical Simulators for Complex Morhpology

    DEFF Research Database (Denmark)

    Mosegaard, Jesper; Sørensen, Thomas Sangild


    Surgical training in virtual environments, surgical simulation in other words, has previously had difficulties in simulating deformation of complex morphology in real-time. Even fast spring-mass based systems had slow convergence rates for large models. This paper presents two methods to accelerate...

  8. Surgical revascularization induces angiogenesis in orthotopic bone allograft

    NARCIS (Netherlands)

    Willems, Wouter F.; Kremer, Thomas; Friedrich, Patricia; Bishop, Allen T.


    Remodeling of structural bone allografts relies on adequate revascularization, which can theoretically be induced by surgical revascularization. We developed a new orthotopic animal model to determine the technical feasibility of axial arteriovenous bundle implantation and resultant angiogenesis. We

  9. Surgical anatomy of the temporal bone: an atlas

    International Nuclear Information System (INIS)

    Chan, L.L.; Manolidis, S.; Taber, K.H.; Hayman, L.A.


    This atlas demonstrates the usefulness of reconstructed high-resolution CT for planning temporal bone surgery. The first part focuses on a sagittal plane, the second on a rotated longitudinal plane, and the third on a rotated transverse plane. We believe knowledge of temporal bone anatomy in these planes facilitates surgical planning by showing anatomic relationships and providing a customized map for each patient. This decreases the likelihood of surgical mishap and improves teaching. (orig.)

  10. In vitro simulation of pathological bone conditions to predict clinical outcome of bone tissue engineered materials (United States)

    Nguyen, Duong Thuy Thi

    According to the Centers for Disease Control, the geriatric population of ≥65 years of age will increase to 51.5 million in 2020; 40% of white women and 13% of white men will be at risk for fragility fractures or fractures sustained under normal stress and loading conditions due to bone disease, leading to hospitalization and surgical treatment. Fracture management strategies can be divided into pharmaceutical therapy, surgical intervention, and tissue regeneration for fracture prevention, fracture stabilization, and fracture site regeneration, respectively. However, these strategies fail to accommodate the pathological nature of fragility fractures, leading to unwanted side effects, implant failures, and non-unions. Compromised innate bone healing reactions of patients with bone diseases are exacerbated with protective bone therapy. Once these patients sustain a fracture, bone healing is a challenge, especially when fracture stabilization is unsuccessful. Traditional stabilizing screw and plate systems were designed with emphasis on bone mechanics rather than biology. Bone grafts are often used with fixation devices to provide skeletal continuity at the fracture gap. Current bone grafts include autologous bone tissue and donor bone tissue; however, the quality and quantity demanded by fragility fractures sustained by high-risk geriatric patients and patients with bone diseases are not met. Consequently, bone tissue engineering strategies are advancing towards functionalized bone substitutes to provide fracture reconstruction while effectively mediating bone healing in normal and diseased fracture environments. In order to target fragility fractures, fracture management strategies should be tailored to allow bone regeneration and fracture stabilization with bioactive bone substitutes designed for the pathological environment. The clinical outcome of these materials must be predictable within various disease environments. Initial development of a targeted

  11. Assessment of surgeon fatigue by surgical simulators


    Sikder, Shameema; Tuwairqi,Khaled; Selter,Jessica


    Khaled Tuwairqi,1 Jessica H Selter,2 Shameema Sikder3 1College of Medicine, University of Utah, Salt Lake City, UT, 2Johns Hopkins School of Medicine, 3Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA Background: The impact of fatigue on surgical performance and its implications for patient care is a growing concern. While investigators have employed a number of different tools to measure the effect of fatigue on surgical performance, the use of the surgical simulator has b...

  12. Pathological Bones Fragility: Drug Treatment of Bone Tissue and Surgical Correction of Bones Deformation

    Directory of Open Access Journals (Sweden)

    Yu. M. Guk


    Full Text Available The paper presents a current approach to treatment of patients with orthopaedic pathology associated with imperfect osteogenesis as well as a promising trend of drug therapy of bone tissue and surgical treatment of pathological fractures and axial deformation of long bones. The authors analyzed the results of treatment of 22 patients with imperfect osteogenesis using a new method consisted of pathogenetic antiosteoporosis therapy and «growing» telescope-type intramedullary constructions. The effectiveness and potential of the mentioned method for treatment and prevention have been determined and approved through objective evidence.

  13. Assessment of surgeon fatigue by surgical simulators

    Directory of Open Access Journals (Sweden)

    Tuwairqi K


    Full Text Available Khaled Tuwairqi,1 Jessica H Selter,2 Shameema Sikder3 1College of Medicine, University of Utah, Salt Lake City, UT, 2Johns Hopkins School of Medicine, 3Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA Background: The impact of fatigue on surgical performance and its implications for patient care is a growing concern. While investigators have employed a number of different tools to measure the effect of fatigue on surgical performance, the use of the surgical simulator has been increasingly implemented for this purpose. The goal of this paper is to review the published literature to achieve a better understanding of evaluation of fatigue on performance as studied with surgical simulators. Methods: A PubMed and Cochrane search was conducted using the search terms “simulator”, “surgery”, and “fatigue”. In total, 50 papers were evaluated, and 20 studies were selected after application of exclusion criteria. Articles were excluded if they did not use the simulator to assess the impact of fatigue on surgeon performance. Systematic reviews and case reports were also excluded. Results: Surgeon fatigue led to a consistent decline in cognitive function in six studies. Technical skills were evaluated in 18 studies, and a detrimental impact was reported in nine studies, while the remaining nine studies showed either no change or positive results with regard to surgical skills after experience of fatigue. Two pharmacological intervention studies reversed the detrimental impact of fatigue on cognitive function, but no change or a worsening effect was recognized for technical skills. Conclusion: Simulators are increasingly being used to evaluate the impact of fatigue on the surgeon's performance. With regard to the impact of fatigue in this regard, studies have demonstrated a consistent decline in cognitive function and mixed outcomes for technical skills. Larger studies that relate the simulator's results to real surgical

  14. Recapping hemilaminoplasty for spinal surgical disorders using ultrasonic bone curette. (United States)

    Matsuoka, Hidenori; Itoh, Yasunobu; Numazawa, Shinichi; Tomii, Masato; Watanabe, Kazuo; Hirano, Yoshitaka; Nakagawa, Hiroshi


    The authors present a novel method of the recapping hemilaminoplasty in a retrospective study of patients with spinal surgical disorders. This report describes the surgical technique and the results of hemilaminoplasty using an ultrasonic bone curette. The aim of this study was to examine the safety and effectiveness of the hemilaminoplasty technique with ultrasonic bone curette. Between April 2003 and July 2011, 33 patients with various spinal diseases (17 spinal tumors, 5 dural arteriovenous fistulas, 3 syringomyelia, 2 sacral perineural cysts, and 2 arachnoid cysts) were treated microsurgically by using an ultrasonic bone curette with scalpel blade and lightweight handpiece. The ultrasonic bone curette was used for division of lamina. After resection of the lesion, the excised lamina was replaced exactly in situ to its original anatomic position with a titanium plate and screw. Additional fusion technique was not required and the device was easy to handle. All patients were observed both neurologically and radiologically by dynamic plain radiographs and computed tomography (CT) scan. The operation was performed successfully and there were no instrument-related complications such as dural laceration, nerve root injury, and vessels injury. The mean number of resected and restored lamina was 1.7. CT confirmed primary bone fusion in all patients by 12 months after surgery. The ultrasonic bone curette is a useful instrument for recapping hemilaminoplasty in various spinal surgeries. This method allows anatomical reconstruction of the excised bone to preserve the posterior surrounding tissues.

  15. The Role and Validity of Surgical Simulation


    Agha, Riaz A.; Fowler, Alexander J.


    In the last three decades, simulation has become a key tool in the training of doctors and the maintenance of patient safety. Simulation offers an immersive, realistic way of learning technical skills. Recent changes to the training schemes in many surgical specialities mean that the hours spent working between senior house officer and consultant have been reduced. This, combined with other pressures (such as reduced operating hours), means that surgery has moved away from its traditional app...

  16. Virtual reality simulation in endovascular surgical training.

    LENUS (Irish Health Repository)

    Tsang, J S


    Shortened trainingtimes duetothe European Working Time Directive (EWTD) and increased public scrutiny of surgical competency have led to a move away from the traditional apprenticeship model of training. Virtual reality (VR) simulation is a fascinating innovation allowing surgeons to develop without the need to practice on real patients and it may be a solution to achieve competency within a shortened training period.

  17. Cochlear implant simulator for surgical technique analysis (United States)

    Turok, Rebecca L.; Labadie, Robert F.; Wanna, George B.; Dawant, Benoit M.; Noble, Jack H.


    Cochlear Implant (CI) surgery is a procedure in which an electrode array is inserted into the cochlea. The electrode array is used to stimulate auditory nerve fibers and restore hearing for people with severe to profound hearing loss. The primary goals when placing the electrode array are to fully insert the array into the cochlea while minimizing trauma to the cochlea. Studying the relationship between surgical outcome and various surgical techniques has been difficult since trauma and electrode placement are generally unknown without histology. Our group has created a CI placement simulator that combines an interactive 3D visualization environment with a haptic-feedback-enabled controller. Surgical techniques and patient anatomy can be varied between simulations so that outcomes can be studied under varied conditions. With this system, we envision that through numerous trials we will be able to statistically analyze how outcomes relate to surgical techniques. As a first test of this system, in this work, we have designed an experiment in which we compare the spatial distribution of forces imparted to the cochlea in the array insertion procedure when using two different but commonly used surgical techniques for cochlear access, called round window and cochleostomy access. Our results suggest that CIs implanted using round window access may cause less trauma to deeper intracochlear structures than cochleostomy techniques. This result is of interest because it challenges traditional thinking in the otological community but might offer an explanation for recent anecdotal evidence that suggests that round window access techniques lead to better outcomes.

  18. Standardization of surgical techniques used in facial bone contouring. (United States)

    Lee, Tae Sung


    Since the introduction of facial bone contouring surgery for cosmetic purposes, various surgical methods have been used to improve the aesthetics of facial contours. In general, by standardizing the surgical techniques, it is possible to decrease complication rates and achieve more predictable surgical outcomes, thereby increasing patient satisfaction. The technical strategies used by the author to standardize facial bone contouring procedures are introduced here. The author uses various pre-manufactured surgical tools and hardware for facial bone contouring. During a reduction malarplasty or genioplasty procedure, double-bladed reciprocating saws and pre-bent titanium plates customized for the zygomatic body, arch and chin are used. Various guarded oscillating saws are used for mandibular angloplasty. The use of double-bladed saws and pre-bent plates to perform reduction malarplasty reduces the chances of post-operative asymmetry or under- or overcorrection of the zygoma contours due to technical faults. Inferior alveolar nerve injury and post-operative jawline asymmetry or irregularity can be reduced by using a guarded saw during mandibular angloplasty. For genioplasty, final placement of the chin in accordance with preoperative quantitative analysis can be easily performed with pre-bent plates, and a double-bladed saw allows more procedural accuracy during osteotomies. Efforts by the surgeon to avoid unintentional faults are key to achieving satisfactory results and reducing the incidence of complications. The surgical techniques described in this study in conjunction with various in-house surgical tools and modified hardware can be used to standardize techniques to achieve aesthetically gratifying outcomes. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  19. Time Simulation of Bone Adaptation

    DEFF Research Database (Denmark)

    Bagge, Mette


    The structural adaptation of a three-dimensional finite element model ofthe proximal femur is considered. Presuming the bone possesses the optimalstructure under the given loads, the bone material distribution is foundby minimizing the strain energy averaged over ten load cases with avolume...

  20. Incorporating simulation into gynecologic surgical training. (United States)

    Wohlrab, Kyle; Jelovsek, J Eric; Myers, Deborah


    Today's educational environment has made it more difficult to rely on the Halstedian model of "see one, do one, teach one" in gynecologic surgical training. There is decreased surgical volume, but an increased number of surgical modalities. Fortunately, surgical simulation has evolved to fill the educational void. Whether it is through skill generalization or skill transfer, surgical simulation has shifted learning from the operating room back to the classroom. This article explores the principles of surgical education and ways to introduce simulation as an adjunct to residency training. We review high- and low-fidelity surgical simulators, discuss the progression of surgical skills, and provide options for skills competency assessment. Time and money are major hurdles when designing a simulation curriculum, but low-fidelity models, intradepartmental cost sharing, and utilizing local experts for simulation proctoring can aid in developing a simulation program. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Is bone scintigraphy necessary in the initial surgical staging of chondrosarcoma of bone?

    Energy Technology Data Exchange (ETDEWEB)

    Douis, Hassan; James, Steven L.; Davies, Mark A. [Royal Orthopaedic Hospital, Department of Radiology, Birmingham (United Kingdom); Grimer, Robert J. [Royal Orthopaedic Hospital, Department of Orthopaedic Oncology, Birmingham (United Kingdom)


    To assess the value of whole-body bone scintigraphy in the initial surgical staging of chondrosarcoma of bone. A retrospective review was conducted of the bone scintigraphy reports of a large series of patients with peripheral or central chondrosarcoma of bone treated in a specialist orthopaedic oncology unit over a 13-year period. Abnormal findings were correlated against other imaging, histological grade and the impact on surgical staging. A total of 195 chondrosarcomas were identified in 188 patients. In 120 (63.8%) patients the reports of bone scintigraphy noted increased activity at the site of one or more chondrosarcomas. In one patient the tumour was outside the field-of-view of the scan, and in the remaining 67 (35.6%) cases, there was increased activity at the site of the chondrosarcoma and further abnormal activity in other areas of the skeleton. Causes of these additional areas of activity included degenerative joint disease, Paget's disease and in one case a previously undiagnosed melanoma metastasis. No cases of skeletal metastases from the chondrosarcoma were found in this series. Multifocal chondrosarcomas were identified in three cases. In two it was considered that all the tumours would have been adequately revealed on the initial MR imaging staging studies. In only the third multifocal case was an unsuspected, further presumed low-grade, central chondrosarcoma identified in the opposite asymptomatic femur. Although this case revealed an unexpected finding the impact on surgical staging was limited as it was decided to employ a watch-and-wait policy for this tumour. There is little role for the routine use of whole-body bone scintigraphy in the initial surgical staging in patients with chondrosarcoma of bone irrespective of the histological grade. (orig.)

  2. Simulation as a surgical teaching model. (United States)

    Ruiz-Gómez, José Luis; Martín-Parra, José Ignacio; González-Noriega, Mónica; Redondo-Figuero, Carlos Godofredo; Manuel-Palazuelos, José Carlos


    Teaching of surgery has been affected by many factors over the last years, such as the reduction of working hours, the optimization of the use of the operating room or patient safety. Traditional teaching methodology fails to reduce the impact of these factors on surgeońs training. Simulation as a teaching model minimizes such impact, and is more effective than traditional teaching methods for integrating knowledge and clinical-surgical skills. Simulation complements clinical assistance with training, creating a safe learning environment where patient safety is not affected, and ethical or legal conflicts are avoided. Simulation uses learning methodologies that allow teaching individualization, adapting it to the learning needs of each student. It also allows training of all kinds of technical, cognitive or behavioural skills. Copyright © 2017 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Is Surgical Navigation Useful During Closed Reduction of Nasal Bone Fractures? (United States)

    Kim, Seon Tae; Jung, Joo Hyun; Kang, Il Gyu


    To report the case of a 42-year-old woman with a nasal bone fracture that was easily treated using a surgical navigation system. In this clinical report, the authors suggest that intraoperative surgical navigation systems are useful diagnostically and for localizing sites of nasal bone fractures exactly. The patient underwent successful closed reduction of the nasal bone fracture. Surgical navigation is a useful tool for identifying nasal bone fracture locations and for guiding closed reduction. Surgical navigation is recommended when nasal bone fractures are complicated or not well reduced using the ordinary method.

  4. Mixed reality temporal bone surgical dissector: mechanical design. (United States)

    Hochman, Jordan Brent; Sepehri, Nariman; Rampersad, Vivek; Kraut, Jay; Khazraee, Milad; Pisa, Justyn; Unger, Bertram


    The Development of a Novel Mixed Reality (MR) Simulation. An evolving training environment emphasizes the importance of simulation. Current haptic temporal bone simulators have difficulty representing realistic contact forces and while 3D printed models convincingly represent vibrational properties of bone, they cannot reproduce soft tissue. This paper introduces a mixed reality model, where the effective elements of both simulations are combined; haptic rendering of soft tissue directly interacts with a printed bone model. This paper addresses one aspect in a series of challenges, specifically the mechanical merger of a haptic device with an otic drill. This further necessitates gravity cancelation of the work assembly gripper mechanism. In this system, the haptic end-effector is replaced by a high-speed drill and the virtual contact forces need to be repositioned to the drill tip from the mid wand. Previous publications detail generation of both the requisite printed and haptic simulations. Custom software was developed to reposition the haptic interaction point to the drill tip. A custom fitting, to hold the otic drill, was developed and its weight was offset using the haptic device. The robustness of the system to disturbances and its stable performance during drilling were tested. The experiments were performed on a mixed reality model consisting of two drillable rapid-prototyped layers separated by a free-space. Within the free-space, a linear virtual force model is applied to simulate drill contact with soft tissue. Testing illustrated the effectiveness of gravity cancellation. Additionally, the system exhibited excellent performance given random inputs and during the drill's passage between real and virtual components of the model. No issues with registration at model boundaries were encountered. These tests provide a proof of concept for the initial stages in the development of a novel mixed-reality temporal bone simulator.

  5. Modelling of non-linear elastic tissues for surgical simulation

    NARCIS (Netherlands)

    Misra, Sarthak; Ramesh, K.T.; Okamura, Allison M.


    Realistic modelling of the interaction between surgical instruments and human organs has been recognised as a key requirement in the development of high-fidelity surgical simulators. Primarily due to computational considerations, most of the past real-time surgical simulation research has assumed

  6. [Simulation training in surgical education - application of virtual reality laparoscopic simulators in a surgical skills course]. (United States)

    Lehmann, K S; Gröne, J; Lauscher, J C; Ritz, J-P; Holmer, C; Pohlen, U; Buhr, H-J


    Training and simulation are gaining importance in surgical education. Today, virtual reality surgery simulators provide sophisticated laparoscopic training scenarios and offer detailed assessment methods. This also makes simulators interesting for the application in surgical skills courses. The aim of the current study was to assess the suitability of a virtual surgery simulator for training and assessment in an established surgical training course. The study was conducted during the annual "Practical Course for Visceral Surgery" (Warnemuende, Germany). 36 of 108 course participants were assigned at random for the study. Training was conducted in 15 sessions over 5 days with 4 identical virtual surgery simulators (LapSim) and 2 standardised training tasks. The simulator measured 16 individual parameters and calculated 2 scores. Questionnaires were used to assess the test persons' laparoscopic experience, their training situation and the acceptance of the simulator training. Data were analysed with non-parametric tests. A subgroup analysis for laparoscopic experience was conducted in order to assess the simulator's construct validity and assessment capabilities. Median age was 32 (27 - 41) years; median professional experience was 3 (1 - 11) years. Typical laparoscopic learning curves with initial significant improvements and a subsequent plateau phase were measured over 5 days. The individual training sessions exhibited a rhythmic variability in the training results. A shorter night's sleep led to a marked drop in performance. The participants' different experience levels could clearly be discriminated ( ≤ 20 vs. > 20 laparoscopic operations; p ≤ 0.001). The questionnaire showed that the majority of the participants had limited training opportunities in their hospitals. The simulator training was very well accepted. However, the participants severely misjudged the real costs of the simulators that were used. The learning curve on the

  7. Assessment of skills using a virtual reality temporal bone surgery simulator. (United States)

    Linke, R; Leichtle, A; Sheikh, F; Schmidt, C; Frenzel, H; Graefe, H; Wollenberg, B; Meyer, J E


    Surgery on the temporal bone is technically challenging due to its complex anatomy. Precise anatomical dissection of the human temporal bone is essential and is fundamental for middle ear surgery. We assessed the possible application of a virtual reality temporal bone surgery simulator to the education of ear surgeons. Seventeen ENT physicians with different levels of surgical training and 20 medical students performed an antrotomy with a computer-based virtual temporal bone surgery simulator. The ease, accuracy and timing of the simulated temporal bone surgery were assessed using the automatic assessment software provided by the simulator device and additionally with a modified Final Product Analysis Scale. Trained ENT surgeons, physicians without temporal bone surgical training and medical students were all able to perform the antrotomy. However, the highly trained ENT surgeons were able to complete the surgery in approximately half the time, with better handling and accuracy as assessed by the significant reduction in injury to important middle ear structures. Trained ENT surgeons achieved significantly higher scores using both dissection analysis methods. Surprisingly, there were no significant differences in the results between medical students and physicians without experience in ear surgery. The virtual temporal bone training system can stratify users of known levels of experience. This system can be used not only to improve the surgical skills of trained ENT surgeons for more successful and injury-free surgeries, but also to train inexperienced physicians/medical students in developing their surgical skills for the ear.

  8. Bone mineral density and fractures after surgical menopause : systematic review and meta-analysis

    NARCIS (Netherlands)

    Fakkert, I. E.; Teixeira, N.; Abma, E. M.; Slart, R. H. J. A.; Mourits, M. J. E.; de Bock, G. H.

    Background Oophorectomy is recommended for women at increased risk for ovarian cancer. When performed at premenopausal age oophorectomy induces acute surgical menopause, with unwanted consequences. Objective To investigate bone mineral density (BMD) and fracture prevalence after surgical menopause.

  9. Skull reconstruction after resection of bone tumors in a single surgical time by the association of the techniques of rapid prototyping and surgical navigation. (United States)

    Anchieta, M V M; Salles, F A; Cassaro, B D; Quaresma, M M; Santos, B F O


    Presentation of a new cranioplasty technique employing a combination of two technologies: rapid prototyping and surgical navigation. This technique allows the reconstruction of the skull cap after the resection of a bone tumor in a single surgical time. The neurosurgeon plans the craniotomy previously on the EximiusMed software, compatible with the Eximius Surgical Navigator, both from the company Artis Tecnologia (Brazil). The navigator imports the planning and guides the surgeon during the craniotomy. The simulation of the bone fault allows the virtual reconstruction of the skull cap and the production of a personalized modelling mold using the Magics-Materialise (Belgium)-software. The mold and a replica of the bone fault are made by rapid prototyping by the company Artis Tecnologia (Brazil) and shipped under sterile conditions to the surgical center. The PMMA prosthesis is produced during the surgical act with the help of a hand press. The total time necessary for the planning and production of the modelling mold is four days. The precision of the mold is submillimetric and accurately reproduces the virtual reconstruction of the prosthesis. The production of the prosthesis during surgery takes until twenty minutes depending on the type of PMMA used. The modelling mold avoids contraction and dissipates the heat generated by the material's exothermic reaction in the polymerization phase. The craniectomy is performed with precision over the drawing made with the help of the Eximius Surgical Navigator, according to the planned measurements. The replica of the bone fault serves to evaluate the adaptation of the prosthesis as a support for the perforations and the placement of screws and fixation plates, as per the surgeon's discretion. This technique allows the adequate oncologic treatment associated with a satisfactory aesthetic result, with precision, in a single surgical time, reducing time and costs.

  10. Preoperative surgical rehearsal using cadaveric fresh tissue surgical simulation increases resident operative confidence. (United States)

    Weber, Erin L; Leland, Hyuma A; Azadgoli, Beina; Minneti, Michael; Carey, Joseph N


    Rehearsal is an essential part of mastering any technical skill. The efficacy of surgical rehearsal is currently limited by low fidelity simulation models. Fresh cadaver models, however, offer maximal surgical simulation. We hypothesize that preoperative surgical rehearsal using fresh tissue surgical simulation will improve resident confidence and serve as an important adjunct to current training methods. Preoperative rehearsal of surgical procedures was performed by plastic surgery residents using fresh cadavers in a simulated operative environment. Rehearsal was designed to mimic the clinical operation, complete with a surgical technician to assist. A retrospective, web-based survey was used to assess resident perception of pre- and post-procedure confidence, preparation, technique, speed, safety, and anatomical knowledge on a 5-point scale (1= not confident, 5= very confident). Twenty-six rehearsals were performed by 9 residents (PGY 1-7) an average of 4.7±2.1 days prior to performance of the scheduled operation. Surveys demonstrated a median pre-simulation confidence score of 2 and a post-rehearsal score of 4 (Psafety, and anatomical knowledge improved as a result of simulation. Fresh tissue-based preoperative surgical rehearsal was effectively implemented in the residency program. Resident confidence and perception of technique improved. Survey results suggest that cadaveric simulation is beneficial for all levels of residents. We believe that implementation of preoperative surgical rehearsal is an effective adjunct to surgical training at all skill levels in the current environment of decreased work hours.

  11. Three-dimensional medical images and its application for surgical simulation of plastic and reconstructive surgery

    International Nuclear Information System (INIS)

    Kaneko, Tsuyoshi; Kobayashi, Masahiro; Nakajima, Hideo; Fujino, Toyomi


    The author's three surgical simulation systems are presented. First the computer graphics surgical simulation system has been developed which make the three dimensional skull image from CT scans and the arbitrary osteotomy, mobilization of bone segments and prediction of post-operative appearance is made possible. The second system is solid modeling of the skull using laser curable resin and it is concluded that life-sized skull model is useful not only for surgical simulation of major craniofacial surgery but also educational purposes. The third one is solid modeling of the ear using non-contact 3-D shape measurement with slit laser scanner. The mirror image life-sized wax model is made from the normal side of th ear and the autologous cartilage framework is assembled to simulate the wax model, thus the precise three dimensional reconstruction of the auricle is made possible. (author)

  12. Virtual Reality Surgical Simulation: Implications for Resection of Intracranial Gliomas. (United States)

    Dakson, Ayoub; Hong, Murray; Clarke, David B


    Surgical simulation has the potential to play important roles in surgical training and preoperative planning. The advent of virtual reality (VR) with tactile haptic feedback has revolutionized surgical simulation, creating a novel environment for residents to learn manual skills without compromising patient safety. This concept is particularly relevant in neurosurgical training where the acquired skill set demands performance of technically challenging tasks under pressure and where the consequences of error are significant. The evolution of VR simulation is discussed here within the context of neurosurgical training and its implications for resection of intracranial gliomas. VR holds the promise of providing a useful educational tool for neurosurgical residents to hone their surgical skills and for neurosurgeons to rehearse specific segments of the surgery prior to the actual operation. Also discussed are several important issues related to simulation and simulation-based training that will need to be addressed before widespread adoption of VR simulation as a useful technology. © 2018 S. Karger AG, Basel.

  13. Web Based Nasal Surgical Simulator Using VRML and Java. (United States)

    Yuan-Yuan, Zhao; Guo-Hong, Zhou; De-Rong, Ye


    This paper describes a nasal surgical simulator that we have designed and implemented to run on the WWW using VRML and Java. In this paper we concentrate on implementation details such as collision detection and the usage of our simulator. At last, we discuss the advantage and disadvantave of the simulator.

  14. Three-dimensional virtual reality surgical planning and simulation workbench for orthognathic surgery. (United States)

    Xia, J; Samman, N; Yeung, R W; Shen, S G; Wang, D; Ip, H H; Tideman, H


    A new integrated computer system, the 3-dimensional (3D) virtual reality surgical planning and simulation workbench for orthognathic surgery (VRSP), is presented. Five major functions are implemented in this system: post-processing and reconstruction of computed tomographic (CT) data, transformation of 3D unique coordinate system geometry, generation of 3D color facial soft tissue models, virtual surgical planning and simulation, and presurgical prediction of soft tissue changes. The basic mensuration functions, such as linear and spatial measurements, are also included. The surgical planning and simulation are based on 3D CT reconstructions, whereas soft tissue prediction is based on an individualized, texture-mapped, color facial soft tissue model. The surgeon "enters" the virtual operatory with virtual reality equipment, "holds" a virtual scalpel, and "operates" on a virtual patient to accomplish actual surgical planning, simulation of the surgical procedure, and prediction of soft tissue changes before surgery. As a final result, a quantitative osteotomy-simulated bone model and predicted color facial model with photorealistic quality can be visualized from any arbitrary viewing point in a personal computer system. This system can be installed in any hospital for daily use.

  15. A virtual reality model of the clivus and surgical simulation via transoral or transnasal route. (United States)

    Wang, Shou-Sen; Li, Jun-Feng; Zhang, Shang-Ming; Jing, Jun-Jie; Xue, Liang


    Neurosurgery in areas with restricted space and complicated anatomy can be greatly aided by the virtual reality (VR) technique. The clivus represents one of such challenging surgical areas, but its VR has not been established. The present study aimed to document a VR model of clival anatomy that may be useful in clival surgery. High resolution CT angiography and MRI were used. The study included a total of 20 patients who did not have any obvious abnormalities detected in the oral, nasal, and clival areas. The images were fused with a Dextroscope. In the VR model, the key structures such as the clival bone, basilar artery, brainstem, pituitary gland, and paranasal sinuses were clearly observed. The morphology of the clivus and its spatial relationships with the neighboring structures were also illustrated. Visualization of the clival model can be made flexible from various planes, angles, or orientations. In addition, surgical access to the clivus via the transoral route or transnasal route was simulated in detail. The simulation of the VR model offers a straightforward, three-dimensional, interactive understanding of the size and shape of the clivus, and its relationships with the surrounding blood vessels and bones. It also demonstrates simulated operational procedures such as opening the surgical window, measuring the exposure distance and angles, and determining the critical boundaries in relation to key structures such as the brainstem and arteries. Digitalized VR modeling appears to be helpful for understanding the anatomy of the clivus and its surgical approaches.

  16. A medical platform for simulation of surgical procedures. (United States)

    Thurfjell, L; Lundin, A; McLaughlin, J


    Surgery simulation is a promising technique for training of surgical procedures. The overall goal for any surgical simulator is to allow for efficient training of the skills required and to improve learning by giving the user proper feedback. This goal is easier achieved if the training is performed in a realistic environment. Therefore functionality such as soft tissue deformation, tearing and cutting, penetration of soft tissue etc. is necessary. Furthermore, a realistic simulator must provide haptic feedback so that all senses match, that is, there should be a correspondence between what you see and what you feel with your hands. In this paper we describe a medical platform that provides all this functionality. It is based on the Reachln Magma API, which has been extended for surgery simulation. We describe the development of the platform and illustrate the use of it for the development of two different types of surgical simulators, both of which represents work in progress.

  17. Surgical management of proximal splint bone fractures in the horse

    International Nuclear Information System (INIS)

    Peterson, P.R.; Pascoe, J.R.; Wheat, J.D.


    Fractures of Metacarpal and Metatarsal II and IV (the splint bones) were treated in 283 horses over an 11 year period. In 21 cases the proximal portion of the fractured bone was stabilized with metallic implants. One or more cortical bone screws were used in 11 horses, and bone plates were applied in 11 horses. One horse received both treatments. Complications of screw fixation included bone failure, implant failure, radiographic lucency around the screws, and proliferative new bone at the ostectomy site. Only two of the horses treated with screw fixation returned to their intended use. Complications of plate fixation included partial fixation failure (backing out of screws), wound drainage, and proliferative bony response around the plate. Six of the 11 horses treated by plate fixation returned to their intended use. The authors recommend consideration of plate fixation techniques for repair of fractures in the proximal third of the splint bone

  18. Gathering Validity Evidence for Surgical Simulation: A Systematic Review. (United States)

    Borgersen, Nanna Jo; Naur, Therese M H; Sørensen, Stine M D; Bjerrum, Flemming; Konge, Lars; Subhi, Yousif; Thomsen, Ann Sofia S


    To identify current trends in the use of validity frameworks in surgical simulation, to provide an overview of the evidence behind the assessment of technical skills in all surgical specialties, and to present recommendations and guidelines for future validity studies. Validity evidence for assessment tools used in the evaluation of surgical performance is of paramount importance to ensure valid and reliable assessment of skills. We systematically reviewed the literature by searching 5 databases (PubMed, EMBASE, Web of Science, PsycINFO, and the Cochrane Library) for studies published from January 1, 2008, to July 10, 2017. We included original studies evaluating simulation-based assessments of health professionals in surgical specialties and extracted data on surgical specialty, simulator modality, participant characteristics, and the validity framework used. Data were synthesized qualitatively. We identified 498 studies with a total of 18,312 participants. Publications involving validity assessments in surgical simulation more than doubled from 2008 to 2010 (∼30 studies/year) to 2014 to 2016 (∼70 to 90 studies/year). Only 6.6% of the studies used the recommended contemporary validity framework (Messick). The majority of studies used outdated frameworks such as face validity. Significant differences were identified across surgical specialties. The evaluated assessment tools were mostly inanimate or virtual reality simulation models. An increasing number of studies have gathered validity evidence for simulation-based assessments in surgical specialties, but the use of outdated frameworks remains common. To address the current practice, this paper presents guidelines on how to use the contemporary validity framework when designing validity studies.

  19. Surgical simulation training in orthopedics: current insights. (United States)

    Kalun, Portia; Wagner, Natalie; Yan, James; Nousiainen, Markku T; Sonnadara, Ranil R


    While the knowledge required of residents training in orthopedic surgery continues to increase, various factors, including reductions in work hours, have resulted in decreased clinical learning opportunities. Recent work suggests residents graduate from their training programs without sufficient exposure to key procedures. In response, simulation is increasingly being incorporated into training programs to supplement clinical learning. This paper reviews the literature to explore whether skills learned in simulation-based settings results in improved clinical performance in orthopedic surgery trainees. A scoping review of the literature was conducted to identify papers discussing simulation training in orthopedic surgery. We focused on exploring whether skills learned in simulation transferred effectively to a clinical setting. Experimental studies, systematic reviews, and narrative reviews were included. A total of 15 studies were included, with 11 review papers and four experimental studies. The review articles reported little evidence regarding the transfer of skills from simulation to the clinical setting, strong evidence that simulator models discriminate among different levels of experience, varied outcome measures among studies, and a need to define competent performance in both simulated and clinical settings. Furthermore, while three out of the four experimental studies demonstrated transfer between the simulated and clinical environments, methodological study design issues were identified. Our review identifies weak evidence as to whether skills learned in simulation transfer effectively to clinical practice for orthopedic surgery trainees. Given the increased reliance on simulation, there is an immediate need for comprehensive studies that focus on skill transfer, which will allow simulation to be incorporated effectively into orthopedic surgery training programs.

  20. [Simulation-based robot-assisted surgical training]. (United States)

    Kolontarev, K B; Govorov, A V; Rasner, P I; Sheptunov, S A; Prilepskaya, E A; Maltsev, E G; Pushkar, D Yu


    Since the first use of robotic surgical system in 2000, the robot-assisted technology has gained wide popularity throughout the world. Robot-assisted surgical training is a complex issue that requires significant efforts from students and teacher. During the last two decades, simulation-based training had received active development due to wide-spread occurrence and popularization of laparoscopic and robot-assisted surgical techniques. We performed a systematic review to identify the currently available simulators for robot-assisted surgery. We searched the Medline and Pubmed, English sources of literature data, using the following key words and phrases: "robotics", "robotic surgery", "computer assisted surgery", "simulation", "computer simulation", "virtual reality", "surgical training", and "surgical education". There were identified 565 publications, which meet the key words and phrases; 19 publications were selected for the final analysis. It was established that simulation-based training is the most promising teaching tool that can be used in the training of the next generation robotic surgeons. Today the use of simulators to train surgeons is validated. Price of devices is an obvious barrier for inclusion in the program for training of robotic surgeons, but the lack of this tool will result in a sharp increase in the duration of specialists training.

  1. Consensus guidelines for validation of virtual reality surgical simulators

    NARCIS (Netherlands)

    Carter, F. J.; Schijven, M. P.; Aggarwal, R.; Grantcharov, T.; Francis, N. K.; Hanna, G. B.; Jakimowicz, J. J.


    The Work Group for Evaluation and Implementation of Simulators and Skills Training Programmes is a newly formed subgroup of the European Association of Endoscopic Surgeons (EAES). This work group undertook a review of validation evidence for surgical simulators and the resulting consensus is

  2. Consensus guidelines for validation of virtual reality surgical simulators

    NARCIS (Netherlands)

    Carter, F. J.; Schijven, M. P.; Aggarwal, R.; Grantcharov, T.; Francis, N. K.; Hanna, G. B.; Jakimowicz, J. J.


    The Work Group for Evaluation and Implementation of Simulators and Skills Training Programmes is a newly formed sub-group of the European Association of Endoscopic Surgeons (EAES). This work group undertook a review of validation evidence for surgical simulators and the resulting consensus is

  3. Utility of 3D printed temporal bones in pre-surgical planning for complex BoneBridge cases. (United States)

    Mukherjee, Payal; Cheng, Kai; Flanagan, Sean; Greenberg, Simon


    With the advent of single-sided hearing loss increasingly being treated with cochlear implantation, bone conduction implants are reserved for cases of conductive and mixed hearing loss with greater complexity. The BoneBridge (BB, MED-EL, Innsbruck, Austria) is an active fully implantable device with no attenuation of sound energy through soft tissue. However, the floating mass transducer (FMT) part of the device is very bulky, which limits insertion in complicated ears. In this study, 3D printed temporal bones of patients were used to study its utility in preoperative planning on complicated cases. Computed tomography (CT) scans of 16 ears were used to 3D print their temporal bones. Three otologists graded the use of routine preoperative planning provided by MED-EL and that of operating on the 3D printed bone of the patient. Data were collated to assess the advantage and disadvantage of the technology. There was a statistically significant benefit in using 3D printed temporal bones to plan surgery for difficult cases of BoneBridge surgery compared to the current standard. Surgeons preferred to have the printed bones in theatre to plan their drill sites and make the transition of the planning to the patient's operation more precise. 3D printing is an innovative use of technology in the use of preoperative planning for complex ear surgery. Surgical planning can be done on the patient's own anatomy which may help to decrease operating time, reduce cost, increase surgical precision and thus reduce complications.

  4. Osteosynthesis in surgical treatment of metastatic lesions of long tubular bones




    Objectives. This study was designed to investigate the causes and risk factors of complications requiring revision surgeries after intramedullary and plate osteosynthesis of the long tubular bones affected by metastases. Methods. Surgical treatment outcomes of patients with long tubular bones metastases (n=44) were analyzed retrospectively. Twelve patients had solitary skeletal metastasis, eleven multiple, twenty one bone metastases combined with visceral metastases. The pathological fracture...

  5. LR-Spring Mass Model for Cardiac Surgical Simulation

    DEFF Research Database (Denmark)

    Mosegaard, Jesper


    The purpose of the research conducted was to develop a real-time surgical simulator for preoperative planning of surgery in congenital heart disease. The main problem simulating procedures on cardiac morphology is the need for a large degree of detail and simulation speed. In combination with a d......The purpose of the research conducted was to develop a real-time surgical simulator for preoperative planning of surgery in congenital heart disease. The main problem simulating procedures on cardiac morphology is the need for a large degree of detail and simulation speed. In combination...... with a demand for physically realistic real-time behaviour this gives us tradeoffs not easily balanced. The LR-Spring Mass model handles these constraints by the use of domain specific knowledge....

  6. Simulators and the simulation environment: getting the balance right in simulation-based surgical education. (United States)

    Sadideen, Hazim; Hamaoui, Karim; Saadeddin, Munir; Kneebone, Roger


    Simulation occupies a central position in surgical education. It offers a safe environment for trainees to develop and improve their skills through sustained deliberate self-practice and appropriate feedback. This review explores the role of simulators and the simulation environment in light of educational theory to promote effective learning. Information was obtained from peer-reviewed publications, books and online material. A simplistic perspective frames simulation as a means of gaining technical skills on basic models by offering a safe alternative to carrying out procedures on real patients. Although necessary, that aspect of simulation requires greater depth to satisfy the growing demand for alternatives to traditional clinical learning. A more realistic view should frame simulation as a means to gaining mastery within a complex clinical world. In order to strike the balance on simulating an ideal clinical scenario, alignment of the simulator and the simulation environment in the appropriate context appears crucial. Copyright © 2012 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  7. Haptic Feedback for the GPU-based Surgical Simulator

    DEFF Research Database (Denmark)

    Sørensen, Thomas Sangild; Mosegaard, Jesper


    The GPU has proven to be a powerful processor to compute spring-mass based surgical simulations. It has not previously been shown however, how to effectively implement haptic interaction with a simulation running entirely on the GPU. This paper describes a method to calculate haptic feedback...... with limited performance cost. It allows easy balancing of the GPU workload between calculations of simulation, visualisation, and the haptic feedback....

  8. Challenges to the development of complex virtual reality surgical simulations. (United States)

    Seymour, N E; Røtnes, J S


    Virtual reality simulation in surgical training has become more widely used and intensely investigated in an effort to develop safer, more efficient, measurable training processes. The development of virtual reality simulation of surgical procedures has begun, but well-described technical obstacles must be overcome to permit varied training in a clinically realistic computer-generated environment. These challenges include development of realistic surgical interfaces and physical objects within the computer-generated environment, modeling of realistic interactions between objects, rendering of the surgical field, and development of signal processing for complex events associated with surgery. Of these, the realistic modeling of tissue objects that are fully responsive to surgical manipulations is the most challenging. Threats to early success include relatively limited resources for development and procurement, as well as smaller potential for return on investment than in other simulation industries that face similar problems. Despite these difficulties, steady progress continues to be made in these areas. If executed properly, virtual reality offers inherent advantages over other training systems in creating a realistic surgical environment and facilitating measurement of surgeon performance. Once developed, complex new virtual reality training devices must be validated for their usefulness in formative training and assessment of skill to be established.

  9. [Animal experimentation, computer simulation and surgical research]. (United States)

    Carpentier, Alain


    We live in a digital world In medicine, computers are providing new tools for data collection, imaging, and treatment. During research and development of complex technologies and devices such as artificial hearts, computer simulation can provide more reliable information than experimentation on large animals. In these specific settings, animal experimentation should serve more to validate computer models of complex devices than to demonstrate their reliability.

  10. Adaptive scapula bone remodeling computational simulation: Relevance to regenerative medicine (United States)

    Sharma, Gulshan B.; Robertson, Douglas D.


    Shoulder arthroplasty success has been attributed to many factors including, bone quality, soft tissue balancing, surgeon experience, and implant design. Improved long-term success is primarily limited by glenoid implant loosening. Prosthesis design examines materials and shape and determines whether the design should withstand a lifetime of use. Finite element (FE) analyses have been extensively used to study stresses and strains produced in implants and bone. However, these static analyses only measure a moment in time and not the adaptive response to the altered environment produced by the therapeutic intervention. Computational analyses that integrate remodeling rules predict how bone will respond over time. Recent work has shown that subject-specific two- and three dimensional adaptive bone remodeling models are feasible and valid. Feasibility and validation were achieved computationally, simulating bone remodeling using an intact human scapula, initially resetting the scapular bone material properties to be uniform, numerically simulating sequential loading, and comparing the bone remodeling simulation results to the actual scapula's material properties. Three-dimensional scapula FE bone model was created using volumetric computed tomography images. Muscle and joint load and boundary conditions were applied based on values reported in the literature. Internal bone remodeling was based on element strain-energy density. Initially, all bone elements were assigned a homogeneous density. All loads were applied for 10 iterations. After every iteration, each bone element's remodeling stimulus was compared to its corresponding reference stimulus and its material properties modified. The simulation achieved convergence. At the end of the simulation the predicted and actual specimen bone apparent density were plotted and compared. Location of high and low predicted bone density was comparable to the actual specimen. High predicted bone density was greater than actual

  11. Adaptive scapula bone remodeling computational simulation: Relevance to regenerative medicine

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Gulshan B., E-mail: [Emory University, Department of Radiology and Imaging Sciences, Spine and Orthopaedic Center, Atlanta, Georgia 30329 (United States); University of Pittsburgh, Swanson School of Engineering, Department of Bioengineering, Pittsburgh, Pennsylvania 15213 (United States); University of Calgary, Schulich School of Engineering, Department of Mechanical and Manufacturing Engineering, Calgary, Alberta T2N 1N4 (Canada); Robertson, Douglas D., E-mail: [Emory University, Department of Radiology and Imaging Sciences, Spine and Orthopaedic Center, Atlanta, Georgia 30329 (United States); University of Pittsburgh, Swanson School of Engineering, Department of Bioengineering, Pittsburgh, Pennsylvania 15213 (United States)


    Shoulder arthroplasty success has been attributed to many factors including, bone quality, soft tissue balancing, surgeon experience, and implant design. Improved long-term success is primarily limited by glenoid implant loosening. Prosthesis design examines materials and shape and determines whether the design should withstand a lifetime of use. Finite element (FE) analyses have been extensively used to study stresses and strains produced in implants and bone. However, these static analyses only measure a moment in time and not the adaptive response to the altered environment produced by the therapeutic intervention. Computational analyses that integrate remodeling rules predict how bone will respond over time. Recent work has shown that subject-specific two- and three dimensional adaptive bone remodeling models are feasible and valid. Feasibility and validation were achieved computationally, simulating bone remodeling using an intact human scapula, initially resetting the scapular bone material properties to be uniform, numerically simulating sequential loading, and comparing the bone remodeling simulation results to the actual scapula’s material properties. Three-dimensional scapula FE bone model was created using volumetric computed tomography images. Muscle and joint load and boundary conditions were applied based on values reported in the literature. Internal bone remodeling was based on element strain-energy density. Initially, all bone elements were assigned a homogeneous density. All loads were applied for 10 iterations. After every iteration, each bone element’s remodeling stimulus was compared to its corresponding reference stimulus and its material properties modified. The simulation achieved convergence. At the end of the simulation the predicted and actual specimen bone apparent density were plotted and compared. Location of high and low predicted bone density was comparable to the actual specimen. High predicted bone density was greater than

  12. Developing effective automated feedback in temporal bone surgery simulation. (United States)

    Wijewickrema, Sudanthi; Piromchai, Patorn; Zhou, Yun; Ioannou, Ioanna; Bailey, James; Kennedy, Gregor; O'Leary, Stephen


    We aim to test the effectiveness, accuracy, and usefulness of an automated feedback system in facilitating skill acquisition in virtual reality surgery. We evaluate the performance of the feedback system through a randomized controlled trial of 24 students allocated to feedback and nonfeedback groups. The feedback system was based on the Melbourne University temporal bone surgery simulator. The study was conducted at the simulation laboratory of the Royal Victorian Eye and Ear Hospital, Melbourne. The study participants were medical students from the University of Melbourne, who were asked to perform virtual cortical mastoidectomy on the simulator. The extent to which the drilling behavior of the feedback and nonfeedback groups differed was used to evaluate the effectiveness of the system. Its accuracy was determined through a postexperiment observational assessment of recordings made during the experiment by an expert surgeon. Its usability was evaluated using students' self-reports of their impressions of the system. A Friedman's test showed that there was a significant improvement in the drilling performance of the feedback group, χ(2)(1) = 14.450, P feedback (when trainee behavior was detected) 88.6% of the time and appropriate feedback (accurate advice) 84.2% of the time. Participants' opinions about the usefulness of the system were highly positive. The automated feedback system was observed to be effective in improving surgical technique, and the provided feedback was found to be accurate and useful. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  13. Microtomographic imaging in the process of bone modeling and simulation (United States)

    Mueller, Ralph


    Micro-computed tomography ((mu) CT) is an emerging technique to nondestructively image and quantify trabecular bone in three dimensions. Where the early implementations of (mu) CT focused more on technical aspects of the systems and required equipment not normally available to the general public, a more recent development emphasized practical aspects of micro- tomographic imaging. That system is based on a compact fan- beam type of tomograph, also referred to as desktop (mu) CT. Desk-top (mu) CT has been used extensively for the investigation of osteoporosis related health problems gaining new insight into the organization of trabecular bone and the influence of osteoporotic bone loss on bone architecture and the competence of bone. Osteoporosis is a condition characterized by excessive bone loss and deterioration in bone architecture. The reduced quality of bone increases the risk of fracture. Current imaging technologies do not allow accurate in vivo measurements of bone structure over several decades or the investigation of the local remodeling stimuli at the tissue level. Therefore, computer simulations and new experimental modeling procedures are necessary for determining the long-term effects of age, menopause, and osteoporosis on bone. Microstructural bone models allow us to study not only the effects of osteoporosis on the skeleton but also to assess and monitor the effectiveness of new treatment regimens. The basis for such approaches are realistic models of bone and a sound understanding of the underlying biological and mechanical processes in bone physiology. In this article, strategies for new approaches to bone modeling and simulation in the study and treatment of osteoporosis and age-related bone loss are presented. The focus is on the bioengineering and imaging aspects of osteoporosis research. With the introduction of desk-top (mu) CT, a new generation of imaging instruments has entered the arena allowing easy and relatively inexpensive access to

  14. Role of virtual simulation in surgical training. (United States)

    Zerbato, Davide; Dall'Alba, Diego


    The comparison of the developments obtained by training for aviation with the ones obtained by training for surgery highlights the efforts that are still required to define shared and validated training curricula for surgeons. This work focuses on robotic assisted surgery and the related training systems to analyze the current approaches to surgery training based on virtual environments. Limits of current simulation technology are highlighted and the systems currently on the market are compared in terms of their mechanical design and characteristics of the virtual environments offered. In particular the analysis focuses on the level of realism, both graphical and physical, and on the set of training tasks proposed. Some multimedia material is proposed to support the analysis and to highlight the differences between the simulations and the approach to training. From this analysis it is clear that, although there are several training systems on the market, some of them with a lot of scientific literature proving their validity, there is no consensus about the tasks to include in a training curriculum or the level of realism required to virtual environments to be useful.

  15. A GPU Accelerated Spring Mass System for Surgical Simulation

    DEFF Research Database (Denmark)

    Mosegaard, Jesper; Sørensen, Thomas Sangild


    There is a growing demand for surgical simulators to dofast and precise calculations of tissue deformation to simulateincreasingly complex morphology in real-time. Unfortunately, evenfast spring-mass based systems have slow convergence rates for largemodels. This paper presents a method to accele...... to accelerate computation of aspring-mass system in order to simulate a complex organ such as theheart. This acceleration is achieved by taking advantage of moderngraphics processing units (GPU)....

  16. 3D Printed Surgical Simulation Models as educational tool by maxillofacial surgeons. (United States)

    Werz, S M; Zeichner, S J; Berg, B-I; Zeilhofer, H-F; Thieringer, F


    The aim of this study was to evaluate whether inexpensive 3D models can be suitable to train surgical skills to dental students or oral and maxillofacial surgery residents. Furthermore, we wanted to know which of the most common filament materials, acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA), can better simulate human bone according to surgeons' subjective perceptions. Upper and lower jaw models were produced with common 3D desktop printers, ABS and PLA filament and silicon rubber for soft tissue simulation. Those models were given to 10 blinded, experienced maxillofacial surgeons to perform sinus lift and wisdom teeth extraction. Evaluation was made using a questionnaire. Because of slightly different density and filament prices, each silicon-covered model costs between 1.40-1.60 USD (ABS) and 1.80-2.00 USD (PLA) based on 2017 material costs. Ten experienced raters took part in the study. All raters deemed the models suitable for surgical education. No significant differences between ABS and PLA were found, with both having distinct advantages. The study demonstrated that 3D printing with inexpensive printing filaments is a promising method for training oral and maxillofacial surgery residents or dental students in selected surgical procedures. With a simple and cost-efficient manufacturing process, models of actual patient cases can be produced on a small scale, simulating many kinds of surgical procedures. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. High-fidelity haptic and visual rendering for patient-specific simulation of temporal bone surgery. (United States)

    Chan, Sonny; Li, Peter; Locketz, Garrett; Salisbury, Kenneth; Blevins, Nikolas H


    Medical imaging techniques provide a wealth of information for surgical preparation, but it is still often the case that surgeons are examining three-dimensional pre-operative image data as a series of two-dimensional images. With recent advances in visual computing and interactive technologies, there is much opportunity to provide surgeons an ability to actively manipulate and interpret digital image data in a surgically meaningful way. This article describes the design and initial evaluation of a virtual surgical environment that supports patient-specific simulation of temporal bone surgery using pre-operative medical image data. Computational methods are presented that enable six degree-of-freedom haptic feedback during manipulation, and that simulate virtual dissection according to the mechanical principles of orthogonal cutting and abrasive wear. A highly efficient direct volume renderer simultaneously provides high-fidelity visual feedback during surgical manipulation of the virtual anatomy. The resulting virtual surgical environment was assessed by evaluating its ability to replicate findings in the operating room, using pre-operative imaging of the same patient. Correspondences between surgical exposure, anatomical features, and the locations of pathology were readily observed when comparing intra-operative video with the simulation, indicating the predictive ability of the virtual surgical environment.

  18. Surgical Space Suits Increase Particle and Microbiological Emission Rates in a Simulated Surgical Environment. (United States)

    Vijaysegaran, Praveen; Knibbs, Luke D; Morawska, Lidia; Crawford, Ross W


    The role of space suits in the prevention of orthopedic prosthetic joint infection remains unclear. Recent evidence suggests that space suits may in fact contribute to increased infection rates, with bioaerosol emissions from space suits identified as a potential cause. This study aimed to compare the particle and microbiological emission rates (PER and MER) of space suits and standard surgical clothing. A comparison of emission rates between space suits and standard surgical clothing was performed in a simulated surgical environment during 5 separate experiments. Particle counts were analyzed with 2 separate particle counters capable of detecting particles between 0.1 and 20 μm. An Andersen impactor was used to sample bacteria, with culture counts performed at 24 and 48 hours. Four experiments consistently showed statistically significant increases in both PER and MER when space suits are used compared with standard surgical clothing. One experiment showed inconsistent results, with a trend toward increases in both PER and MER when space suits are used compared with standard surgical clothing. Space suits cause increased PER and MER compared with standard surgical clothing. This finding provides mechanistic evidence to support the increased prosthetic joint infection rates observed in clinical studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Alveolar bone regeneration pattern following surgical and non ...

    African Journals Online (AJOL)


    Dec 7, 2002 ... hygiene and degree of mobility with loss of attachment were measured at baseline, 1,3 and 6 months after treatment. Standardized reproducible radiographs of the interproxi- mal sites were taken before and 6 months after treatment. Al- veolar bone levels pre and post treatment were measured with.

  20. Alveolar bone regeneration pattern following surgical and non ...

    African Journals Online (AJOL)

    One hundred and fifty six interproximal sites, with periodontal pockets deeper than 5mm and showing loss of bone on standard dental periapical radiographs, were treated by subgingival instrumentation and open periodontal flap debridement in 12 patients properly motivated and given thorough oral hygiene instructions.

  1. Evaluation of a haptics-based virtual reality temporal bone simulator for anatomy and surgery training. (United States)

    Fang, Te-Yung; Wang, Pa-Chun; Liu, Chih-Hsien; Su, Mu-Chun; Yeh, Shih-Ching


    Virtual reality simulation training may improve knowledge of anatomy and surgical skills. We evaluated a 3-dimensional, haptic, virtual reality temporal bone simulator for dissection training. The subjects were 7 otolaryngology residents (3 training sessions each) and 7 medical students (1 training session each). The virtual reality temporal bone simulation station included a computer with software that was linked to a force-feedback hand stylus, and the system recorded performance and collisions with vital anatomic structures. Subjects performed virtual reality dissections and completed questionnaires after the training sessions. Residents and students had favorable responses to most questions of the technology acceptance model (TAM) questionnaire. The average TAM scores were above neutral for residents and medical students in all domains, and the average TAM score for residents was significantly higher for the usefulness domain and lower for the playful domain than students. The average satisfaction questionnaire for residents showed that residents had greater overall satisfaction with cadaver temporal bone dissection training than training with the virtual reality simulator or plastic temporal bone. For medical students, the average comprehension score was significantly increased from before to after training for all anatomic structures. Medical students had significantly more collisions with the dura than residents. The residents had similar mean performance scores after the first and third training sessions for all dissection procedures. The virtual reality temporal bone simulator provided satisfactory training for otolaryngology residents and medical students. Copyright © 2013. Published by Elsevier Ireland Ltd.

  2. Characterisation and modelling of brain tissue for surgical simulation. (United States)

    Mendizabal, A; Aguinaga, I; Sánchez, E


    Interactive surgical simulators capable of providing a realistic visual and haptic feedback to users are a promising technology for medical training and surgery planification. However, modelling the physical behaviour of human organs and tissues for surgery simulation remains a challenge. On the one hand, this is due to the difficulty to characterise the physical properties of biological soft tissues. On the other hand, the challenge still remains in the computation time requirements of real-time simulation required in interactive systems. Real-time surgical simulation and medical training must employ a sufficiently accurate and simple model of soft tissues in order to provide a realistic haptic and visual response. This study attempts to characterise the brain tissue at similar conditions to those that take place on surgical procedures. With this aim, porcine brain tissue is characterised, as a surrogate of human brain, on a rotational rheometer at low strain rates and large strains. In order to model the brain tissue with an adequate level of accuracy and simplicity, linear elastic, hyperelastic and quasi-linear viscoelastic models are defined. These models are simulated using the ABAQUS finite element platform and compared with the obtained experimental data. Copyright © 2015 Elsevier Ltd. All rights reserved.


    Directory of Open Access Journals (Sweden)

    S. V. Dianov


    Full Text Available The material of investigation was the results of treatment of 131 patients with foot bones tumours. The largest number of patients referred, to age interval from 11 to 30 years (69,6%. More than half of cases were osteochondromas (54%, then solitary bone cyst (14,5% and chondromas (13%. Other nosologic forms were met significantly seldom. Two groups of patients were examined: the main group (with crio-influence - 44 patients and group of comparison (without crio-influence - 87 patients. The plot of operation was in flat, border-line, intrafocusal or segmental resection of damaged section, crio-instillation or contact curio-processing of bone and auto- or allopathic of respected defect. The results of treatment were estimated in a year after operation. After usage of curio-surgical method there were observed positive results in 41 patients, satisfactory - in 2 and unsatisfactory - in 1. The results of treatment with traditional method were positive in 79 cases, satisfactory - in 2, unsatisfactory - in 6. The worked-out method of curio-surgical treatment of foot bone tumours includes resection of pathological focus, itraoperative crio-influence on bone tissue and bone plastic transplantation of resected, defect. The analysis of criosurgical operations of foot gave the foundation to consider such interventions significant and perspective in treatment of patients with tumours and tumour similar damages of foot bone.

  4. The behavior of adaptive bone-remodeling simulation models

    NARCIS (Netherlands)

    H.H. Weinans (Harrie); R. Huiskes (Rik); H.J. Grootenboer


    textabstractThe process of adaptive bone remodeling can be described mathematically and simulated in a computer model, integrated with the finite element method. In the model discussed here, cortical and trabecular bone are described as continuous materials with variable density. The remodeling rule

  5. Effect of music on surgical skill during simulated intraocular surgery. (United States)

    Kyrillos, Ralph; Caissie, Mathieu


    To evaluate the effect of Mozart music compared to silence on anterior segment surgical skill in the context of simulated intraocular surgery. Prospective stratified and randomized noninferiority trial. Fourteen ophthalmologists and 12 residents in ophthalmology. All participants were asked to perform 4 sets of predetermined tasks on the EyeSI surgical simulator (VRmagic, Mannheim, Germany). The participants completed 1 Capsulorhexis task and 1 Anti-Tremor task during 3 separate visits. The first 2 sets determined the basic level on day 1. Then, the participants were stratified by surgical experience and randomized to be exposed to music (Mozart sonata for 2 pianos in D-K448) during either the third or the fourth set of tasks (day 2 or 3). Surgical skill was evaluated using the parameters recorded by the simulator such as "Total score" and "Time" for both tasks and task-specific parameters such as "Out of tolerance percentage" for the Anti-Tremor task and "Deviation of rhexis radius from 2.5 mm," "Roundness," and "Centering" for the Capsulorhexis task. The data were analyzed using the Wilcoxon signed-rank test. No statistically significant differences were noted between exposure and nonexposure for all the Anti-Tremor task parameters as well as most parameters for the Capsulorhexis task. Two parameters for the Capsulorhexis task showed a strong trend for improvement with exposure to music ("Total score" +23.3%, p = 0.025; "Roundness" +33.0%, p = 0.037). Exposure to music did not negatively impact surgical skills. Moreover, a trend for improvement was shown while listening to Mozart music. Copyright © 2017 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  6. Surgical treatment of a comminuted articular fracture of the accessory carpal bone in a thoroughbred horse

    International Nuclear Information System (INIS)

    Munroe, G.A.; Cauvin, E.


    The clinical, radiographic and ultrasonographic findings in a case ofa comminuted articular fracture of the accessory carpal bone of a thoroughbred chaser are described, and its surgical treatment and aftercare are detailed. The horse made an uneventful recovery and successfully returned to racing

  7. MR imaging findings of painful type II accessory navicular bone: correlation with surgical and pathologic studies

    International Nuclear Information System (INIS)

    Choi, Yun Sun; Lee, Kyung Tai; Kim, Eun Kyung; Kang, Heung Sik


    To evaluate the MR imaging findings of painful type II accessory navicular bone and to correlate these with the surgical and pathologic findings. The MR images of 17 patients with medial foot pain and surgically proven type II accessory navicular abnormalities were reviewed. The changes of signal intensity in the accessory navicular, synchondrosis and adjacent soft tissue, the presence of synchondrosis widening, and posterior tibial tendon (PTT) pathology on the T1-weighted and fat-suppressed T2-weighted images were analyzed. The MR imaging findings were compared with the surgical and pathologic findings. The fat-suppressed T2-weighted images showed high signal intensity in the accessory navicular bones and synchondroses in all patients, and in the soft tissue in 11 (64.7%) of the 17 patients, as well as synchondrosis widening in 3 (17.6%) of the 17 patients. The MR images showed tendon pathology in 12 (75%) of the 16 patients with PTT dysfunction at surgery. The pathologic findings of 16 surgical specimens included areas of osteonecrosis with granulomatous inflammation, fibrosis and destruction of the cartilage cap. The MR imaging findings of painful type II accessory navicular bone are a persistent edema pattern in the accessory navicular bone and within the synchondrosis, indicating osteonecrosis, inflammation and destruction of the cartilage cap. Posterior tibial tendon dysfunction was clinically evident in most patients

  8. Simulating Bone Loss in Microgravity Using Mathematical Formulations of Bone Remodeling (United States)

    Pennline, James A.


    Most mathematical models of bone remodeling are used to simulate a specific bone disease, by disrupting the steady state or balance in the normal remodeling process, and to simulate a therapeutic strategy. In this work, the ability of a mathematical model of bone remodeling to simulate bone loss as a function of time under the conditions of microgravity is investigated. The model is formed by combining a previously developed set of biochemical, cellular dynamics, and mechanical stimulus equations in the literature with two newly proposed equations; one governing the rate of change of the area of cortical bone tissue in a cross section of a cylindrical section of bone and one governing the rate of change of calcium in the bone fluid. The mechanical stimulus comes from a simple model of stress due to a compressive force on a cylindrical section of bone which can be reduced to zero to mimic the effects of skeletal unloading in microgravity. The complete set of equations formed is a system of first order ordinary differential equations. The results of selected simulations are displayed and discussed. Limitations and deficiencies of the model are also discussed as well as suggestions for further research.

  9. A virtual surgical simulator for the lower limbs. (United States)

    Stefanich, L; Cruz-Neira, C


    As the body of knowledge concerning human anatomy and physiology continues to grow, new techniques must emerge to convey it more efficiently to future health care professionals. Computer simulation, interaction and visualization technologies are now being used in the development of virtual training environments. This paper presents a real-time virtual surgical simulator that integrates scientific visualization tools into a surround-screen projection-based (SSPB) immersive environment. This environment focuses on procedures for the lower limbs; however, the techniques described can be applied to other portions of the body. The research consists of three phases: environment modeling, volume visualization and immersive surgical simulation. Environment modeling involved modeling an operating room with all of the relevant elements. The volume visualization phase required the application of marching cubes and decimation techniques to the Visible Human Project (VHP) dataset to generate models of the lower limbs. The simulator integrated modeling and volume visualization to facilitate the rehearsal of medical procedures and interaction with medical information. Interactive cutting, suturing and X-Ray CT placement over the virtual patient's legs were used to probe underlying structures. The simulator is intended to aid medical students in learning anatomy, physiology and radiological analysis without jeopardizing patient care.

  10. Surgical management of complete diaphyseal third metacarpal and metatarsal bone fractures: Clinical outcome in 10 mature horses and 11 foals


    Bischofberger, Andrea S; Fürst, Anton; Auer, Jörg A; Lischer, Christoph J


    Reasons for performing study: Osteosynthesis of third metacarpal (McIII) and third metatarsal (MtIII) bone fractures in horses is a surgical challenge and complications surrounding the repair are common. Retrospective studies evaluating surgical repair, complications and outcome are necessary to increase knowledge and improve success of long bone fracture repair in the horse. Objectives: To evaluate clinical findings, surgical repair, post operative complications and outcome of 10 mature h...

  11. Repair process of surgical defects filled with autogenous bone grafts in tibiae of diabetic rats

    Directory of Open Access Journals (Sweden)

    Jônatas Caldeira Esteves


    Full Text Available From a biological standpoint, the best material for reconstruction of bone defects is the autogenous bone graft. However, as tissue healing is affected under diabetic conditions, major changes might take place in the revascularization, incorporation, replacement and remodeling phases of the grafted area. The purpose of this study was to assess the bone healing process in surgical wounds prepared in tibiae of diabetic rats and filled with autogenous bone. Forty male rats (Rattus norvegicus albinus, Wistar were randomly assigned to receive an endovenous injection (penile vein of either citrate buffer solution (Group 1 - control; n=20 or streptozotocin dissolved in citrate buffer solution (35 mg/kg to induce diabetes (Group 2 - diabetic; n=20. After determination of glycemia, the animals were anesthetized and the anterolateral regions of the tibiae of both limbs were shaved, antisepsis was performed and longitudinal incisions were made in each limb. The tibiae were exposed and two 2mm-diameter surgical cavities were prepared: one in the right limb, filled with particulate autogenous bone and the other in the left limb, filled with blood clot. The animals were euthanized at 10 and 30 postoperative days. The anatomic pieces were obtained, submitted to laboratory processing and sections were stained by hematoxylin and eosin and Masson's Trichrome for histomorphologic and histometric analyses. In both groups, the wounds filled with autogenous bone graft showed better results than those filled with blood clot. The control group showed higher new bone formation in wounds filled with autogenous bone graft at 30 days than the diabetic group, but without statistical significance. It may be concluded that, in general, the new bone formation occurred with autogenous graft was quantitatively similar between control and diabetic groups and qualitatively better in the control group.

  12. Physics-Based Haptic Simulation of Bone Machining. (United States)

    Arbabtafti, M; Moghaddam, M; Nahvi, A; Mahvash, M; Richardson, B; Shirinzadeh, B


    We present a physics-based training simulator for bone machining. Based on experimental studies, the energy required to remove a unit volume of bone is a constant for every particular bone material. We use this physical principle to obtain the forces required to remove bone material with a milling tool rotating at high speed. The rotating blades of the tool are modeled as a set of small cutting elements. The force of interaction between a cutting element and bone is calculated from the energy required to remove a bone chip with an estimated thickness and known material stiffness. The total force acting on the cutter at a particular instant is obtained by integrating the differential forces over all cutting elements engaged. A voxel representation is used to represent the virtual bone and removed chips for calculating forces of machining. We use voxels that carry bone material properties to represent the volumetric haptic body and to apply underlying physical changes during machining. Experimental results of machining samples of a real bone confirm the force model. A real-time haptic implementation of the method in a dental training simulator is described.

  13. Surgical repair of skull fractures in four horses using cuttable bone plates. (United States)

    Dowling, B A; Dart, A J; Trope, G


    Three horses with severely comminuted, open facial bone fractures and one horse with a comminuted, open orbital rim fracture were referred for treatment. Severe facial bone asymmetry and epistaxis were apparent in all cases and subcutaneous emphysema was present in two, however physical and neurological examinations were otherwise normal. Radiography and endoscopy were of some use in assessing the degree of damage, although the true extent of the damage was more apparent at surgery. Surgical reduction of the fractures was recommended to maximise cosmetic and functional outcome. After surgical debridement and reduction of the fractures the bone fragments remained unstable and were not amenable to stabilisation with interfragmentary wires alone, so 2 mm cuttable bone plates were used to maintain fracture alignment. Screw migration occurred in three horses and in one of these horses the plate had to be removed. Other complications were minor and in all horses the fractures healed with good cosmetic and functional outcome. The use of cuttable bone plates should be considered as a reasonable alternative to inter-fragmentary wiring for unstable, comminuted fractures of the facial bones, even where fractures are open.

  14. Particulate bioglass in the regeneration of alveolar bone in dogs: clinical, surgical and radiographic evaluations

    Directory of Open Access Journals (Sweden)

    Alexandre Couto Tsiomis


    Full Text Available Bone loss, either by trauma or other diseases, generates an increasing need for substitutes of this tissue. This study evaluated Bioglass as a bone substitute in the regeneration of the alveolar bone in mandibles of dogs by clinical, surgical and radiological analysis. Twenty-eight adult dogs were randomly separated into two equal groups. In each animal, a bone defect was created on the vestibular surface of the alveolar bone between the roots of the fourth right premolar tooth. In the treated group, the defect was immediately filled with bioglass, while in the control, it remained unfilled. Clinical evaluations were performed daily for a week, as well as x-rays immediately after surgery and at 8, 14, 21, 42, 60, 90 and 120 days post-operative. Most animals in both groups showed no signs of inflammation and wound healing was similar. Radiographic examination revealed a gradual increase of radiopacity in the region of the defect in the control group. In the treated group, initial radiopacity was higher than that of adjacent bone, decreasing until 21 days after surgery. Then it gradually increased until 120 days after surgery, when the defect became undetectable. The results showed that Bioglass integrates into bone tissue, is biocompatible and reduced the period for complete bone regeneration.

  15. Real-time thermographic analysis of low-density bone during implant placement: a randomized parallel-group clinical study comparing lateral condensation with bone drilling surgical technique. (United States)

    Marković, Aleksa; Mišić, Tijana; Mančić, Dragan; Jovanović, Igor; Šćepanović, Miodrag; Jezdić, Zoran


    To compare the effect of two surgical techniques, lateral condensation and bone drilling, on changes in temperature of the adjacent low-density bone during implant placement into posterior maxilla and to investigate the influence of the host factors - age, gender, region of implantation, bone density, and thickness of the cortical bone at the recipient sites. Local bone temperature was measured thermographically during implant placement into posterior maxilla following lateral bone condensing (test group) or bone drilling (controls). The main study outcomes were baseline bone temperature prior to implantation and maximum bone temperature recorded during implantation. Early implant success was evaluated after 6 months of healing. A total of 40 implants were randomly allocated to test and control groups and placed into maxillary premolar and/or molar region of 18 participants of both genders and average age of 51.74 years. All recorded bone temperatures were below the threshold for thermal necrosis. Although both groups showed significant increase in bone temperature during implant placement procedure (P ≤ 0.0005), it was significantly higher for bone condensing compared with drilling (P ≤ 0.0005; 3.79 ± 1.54°C; 1.91 ± 0.70°C respectively). No host factor was singled out as a significant predictor of bone temperature changes, although trend of higher increase was observed in young patients, regardless of gender, during implant placement procedure into maxillary first premolar region with bone density type 3 and cortical layer thicker than 1 mm. Early implant success rate after 6 months follow-up was 100%. Although both surgical techniques, bone condensing and bone drilling, can be considered safe regarding their thermal effect on the bone of posterior maxilla, bone drilling is associated with fewer local bone heating during implantation. Host factors do not affect the bone thermal changes significantly. © 2013 John Wiley & Sons A/S. Published by John Wiley

  16. Esterified hyaluronic acid and autologous bone in the surgical correction of the infra-bone defects. (United States)

    Ballini, Andrea; Cantore, Stefania; Capodiferro, Saverio; Grassi, Felice Roberto


    We study the osteoinductive effect of the hyaluronic acid (HA) by using an esterified low-molecular HA preparation (EHA) as a coadjuvant in the grafting processes to produce bone-like tissue in the presence of employing autologous bone obtained from intra-oral sites, to treat infra-bone defects without covering membrane. We report on 9 patients with periodontal defects treated by EHA and autologous grafting (4 males and 5 females, all non smokers, with a mean age of 43.8 years for females, 40.0 years for males and 42 years for all the group, in good health) with a mean depth of 8.3 mm of the infra-bone defects, as revealed by intra-operative probes. Data were obtained at baseline before treatment and after 10 days, and subsequently at 6, 9, and 24 months after treatment. Clinical results showed a mean gain hi clinical attachment (gCAL) of 2.6mm of the treated sites, confirmed by radiographic evaluation. Such results suggest that autologous bone combined with EHA seems to have good capabilities in accelerating new bone formation in the infra-bone defects.

  17. Learning surgical communication, leadership and teamwork through simulation. (United States)

    Bearman, Margaret; O'Brien, Robert; Anthony, Adrian; Civil, Ian; Flanagan, Brendan; Jolly, Brian; Birks, David; Langcake, Mary; Molloy, Elizabeth; Nestel, Debra


    In Australia and New Zealand, surgical trainees are expected to develop competencies across 9 domains. Although structured training is provided in several domains, there is little or no formal program for professionalism, communication, collaboration, and management and leadership. The Australian federal Department of Health and Aging funded a pilot course in simulation-based education to address these competencies for surgical trainees. This article describes the course and evaluation. Course development: Content and methods drew on best-evidence for teaching and learning these competencies from other disciplines. Course evaluation: Participants completed surveys using rating scales and free text comments to identify aspects of the course that worked well and those that needed improvement. Eleven of 12 participants completed evaluation forms immediately after the course. Participants reported largely meeting learning objectives and valuing the educational methods. High levels of realism in simulations contributed to the ease with which participants immersed themselves in scenarios. This study demonstrates that a course designed to teach competencies in communication, teamwork, leadership, and the encompassing professionalism to surgical trainees is feasible. Although participants valued the content and methods, they identified areas for development. Limitations of the evaluation are highlighted, and further areas for research are identified. Copyright © 2012 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  18. Simulation based planning of surgical interventions in pediatric cardiology (United States)

    Marsden, Alison L.


    Hemodynamics plays an essential role in the progression and treatment of cardiovascular disease. However, while medical imaging provides increasingly detailed anatomical information, clinicians often have limited access to hemodynamic data that may be crucial to patient risk assessment and treatment planning. Computational simulations can now provide detailed hemodynamic data to augment clinical knowledge in both adult and pediatric applications. There is a particular need for simulation tools in pediatric cardiology, due to the wide variation in anatomy and physiology in congenital heart disease patients, necessitating individualized treatment plans. Despite great strides in medical imaging, enabling extraction of flow information from magnetic resonance and ultrasound imaging, simulations offer predictive capabilities that imaging alone cannot provide. Patient specific simulations can be used for in silico testing of new surgical designs, treatment planning, device testing, and patient risk stratification. Furthermore, simulations can be performed at no direct risk to the patient. In this paper, we outline the current state of the art in methods for cardiovascular blood flow simulation and virtual surgery. We then step through pressing challenges in the field, including multiscale modeling, boundary condition selection, optimization, and uncertainty quantification. Finally, we summarize simulation results of two representative examples from pediatric cardiology: single ventricle physiology, and coronary aneurysms caused by Kawasaki disease. These examples illustrate the potential impact of computational modeling tools in the clinical setting.

  19. The role of simulation in developing surgical skills. (United States)

    Akhtar, K S N; Chen, Alvin; Standfield, N J; Gupte, C M


    Surgical training has followed the master-apprentice model for centuries but is currently undergoing a paradigm shift. The traditional model is inefficient with no guarantee of case mix, quality, or quantity. There is a growing focus on competency-based medical education in response to restrictions on doctors' working hours and the traditional mantra of "see one, do one, teach one" is being increasingly questioned. The medical profession is subject to more scrutiny than ever before and is facing mounting financial, clinical, and political pressures. Simulation may be a means of addressing these challenges. It provides a way for trainees to practice technical tasks in a protected environment without putting patients at risk and helps to shorten the learning curve. The evidence for simulation-based training in orthopedic surgery using synthetic models, cadavers, and virtual reality simulators is constantly developing, though further work is needed to ensure the transfer of skills to the operating theatre.

  20. Surgical management of spontaneous cerebrospinal fistulas and encephaloceles of the temporal bone. (United States)

    Kutz, Joe Walter; Johnson, Andrew K; Wick, Cameron C


    To describe the presentation, surgical findings, and outcomes in patients with spontaneous temporal bone cerebrospinal fluid (CSF) fistulas and encephaloceles. Retrospective chart review. A retrospective chart review of patients treated for a spontaneous temporal bone CSF fistula and/or encephalocele over a 10-year period was performed. Data recorded included demographic information, presenting signs and symptoms, radiographic and laboratory studies, surgical approach, materials used for repair, surgical complications, and successful closure of the CSF fistula. Fifty patients were identified. Five patients underwent bilateral procedures, for a total of 55 surgical repairs. Thirty-seven of the patients were female, with a mean age of 57.2 years. Seventy percent of patients were obese, with a mean body mass index of 35.0 kg/m 2 . The most common presentation was tympanostomy tube otorrhea (68%). Seven patients (14%) presented with meningitis. The middle fossa craniotomy approach was used in 87.3% of cases. Hydroxyapatite bone cement was used in 82.4% of cases. There were four surgical complications: seizure, mastoid infection, tympanic membrane retraction, and a delayed subdural hematoma. There were five persistent or recurrent CSF fistulas that underwent successful revision surgery. Spontaneous CSF fistulas are most common in obese females and should be suspected with a chronic middle ear effusion, persistent otorrhea after tympanostomy tube placement, or in patients with a history of meningitis. The middle fossa craniotomy approach with the use of hydroxyapatite bone cement has a high success rate with a low incidence of postoperative complications. 4 Laryngoscope, 2018. © 2018 The American Laryngological, Rhinological and Otological Society, Inc.

  1. Teaching of distal radius shortening osteotomy: three-dimensional procedural simulator versus bone procedural simulator. (United States)

    Naroura, Ismaël; Hidalgo Diaz, Juan José; Xavier, Fred; Baldairon, Florent; Favreau, Henri; Clavert, Philippe; Liverneaux, Philippe


    In order to facilitate the learning of distal radius shortening osteotomy by junior surgeons, the main assumption was that using a three-dimensional procedural simulator was better than a bone procedural simulator. After viewing a video, ten junior surgeons performed a distal radius shortening osteotomy: five with a bone procedural simulator (Group 1) and five with a three-dimensional procedural simulator (Group 2). All subsequently performed the same surgery on fresh cadaveric bones. The duration of the procedure, shortening of the radius, and the level of osteotomy were significantly better in Group 2. The three-dimensional procedural simulator seems to teach distal radius osteotomy better than a bone model and could be useful in teaching and learning bone surgery of the wrist.

  2. Implementation of full patient simulation training in surgical residency. (United States)

    Fernandez, Gladys L; Lee, Patrick C; Page, David W; D'Amour, Elizabeth M; Wait, Richard B; Seymour, Neal E


    Simulated patient care has gained acceptance as a medical education tool but is underused in surgical training. To improve resident clinical management in critical situations relevant to the surgical patient, high-fidelity full patient simulation training was instituted at Baystate Medical Center in 2005 and developed during successive years. We define surgical patient simulation as clinical management performed in a high fidelity environment using a manikin simulator. This technique is intended to be specifically modeled experiential learning related to the knowledge, skills, and behaviors that are fundamental to patient care. We report 3 academic years' use of a patient simulation curriculum. Learners were PGY 1-3 residents; 26 simulated patient care experiences were developed based on (1) designation as a critical management problem that would otherwise be difficult to practice, (2) ability to represent the specific problem in simulation, (3) relevance to the American Board of Surgery (ABS) certifying examination, and/or (4) relevance to institutional quality or morbidity and mortality reports. Although training started in 2005, data are drawn from the period of systematic and mandatory training spanning from July 2006 to June 2009. Training occurred during 1-hour sessions using a computer-driven manikin simulator (METI, Sarasota, Florida). Educational content was provided either before or during presimulation briefing sessions. Scenario areas included shock states, trauma and critical care case management, preoperative processes, and postoperative conditions and complications. All sessions were followed by facilitated debriefing. Likert scale-based multi-item assessments of core competency in medical knowledge, patient care, diagnosis, management, communication, and professionalism were used to generate a performance score for each resident for each simulation (percentage of best possible score). Performance was compared across PGYs by repeated

  3. Multidisciplinary crisis simulations: the way forward for training surgical teams. (United States)

    Undre, Shabnam; Koutantji, Maria; Sevdalis, Nick; Gautama, Sanjay; Selvapatt, Nowlan; Williams, Samantha; Sains, Parvinderpal; McCulloch, Peter; Darzi, Ara; Vincent, Charles


    High-reliability organizations have stressed the importance of non-technical skills for safety and of regularly providing such training to their teams. Recently safety skills training has been applied in the practice of medicine. In this study, we developed and piloted a module using multidisciplinary crisis scenarios in a simulated operating theatre to train entire surgical teams. Twenty teams participated (n = 80); each consisted of a trainee surgeon, anesthetist, operating department practitioner (ODP), and scrub nurse. Crisis scenarios such as difficult intubation, hemorrhage, or cardiac arrest were simulated. Technical and non-technical skills (leadership, communication, team skills, decision making, and vigilance), were assessed by clinical experts and by two psychologists using relevant technical and human factors rating scales. Participants received technical and non-technical feedback, and the whole team received feedback on teamwork. Trainees assessed the training favorably. For technical skills there were no differences between surgical trainees' assessment scores and the assessment scores of the trainers. However, nurses overrated their technical skill. Regarding non-technical skills, leadership and decision making were scored lower than the other three non-technical skills (communication, team skills, and vigilance). Surgeons scored lower than nurses on communication and teamwork skills. Surgeons and anesthetists scored lower than nurses on leadership. Multidisciplinary simulation-based team training is feasible and well received by surgical teams. Non-technical skills can be assessed alongside technical skills, and differences in performance indicate where there is a need for further training. Future work should focus on developing team performance measures for training and on the development and evaluation of systematic training for technical and non-technical skills to enhance team performance and safety in surgery.

  4. Surgical guides (patient-specific instruments) for pediatric tibial bone sarcoma resection and allograft reconstruction. (United States)

    Bellanova, Laura; Paul, Laurent; Docquier, Pierre-Louis


    To achieve local control of malignant pediatric bone tumors and to provide satisfactory oncological results, adequate resection margins are mandatory. The local recurrence rate is directly related to inappropriate excision margins. The present study describes a method for decreasing the resection margin width and ensuring that the margins are adequate. This method was developed in the tibia, which is a common site for the most frequent primary bone sarcomas in children. Magnetic resonance imaging (MRI) and computerized tomography (CT) were used for preoperative planning to define the cutting planes for the tumors: each tumor was segmented on MRI, and the volume of the tumor was coregistered with CT. After preoperative planning, a surgical guide (patient-specific instrument) that was fitted to a unique position on the tibia was manufactured by rapid prototyping. A second instrument was manufactured to adjust the bone allograft to fit the resection gap accurately. Pathologic evaluation of the resected specimens showed tumor-free resection margins in all four cases. The technologies described in this paper may improve the surgical accuracy and patient safety in surgical oncology. In addition, these techniques may decrease operating time and allow for reconstruction with a well-matched allograft to obtain stable osteosynthesis.

  5. Surgical Guides (Patient-Specific Instruments for Pediatric Tibial Bone Sarcoma Resection and Allograft Reconstruction

    Directory of Open Access Journals (Sweden)

    Laura Bellanova


    Full Text Available To achieve local control of malignant pediatric bone tumors and to provide satisfactory oncological results, adequate resection margins are mandatory. The local recurrence rate is directly related to inappropriate excision margins. The present study describes a method for decreasing the resection margin width and ensuring that the margins are adequate. This method was developed in the tibia, which is a common site for the most frequent primary bone sarcomas in children. Magnetic resonance imaging (MRI and computerized tomography (CT were used for preoperative planning to define the cutting planes for the tumors: each tumor was segmented on MRI, and the volume of the tumor was coregistered with CT. After preoperative planning, a surgical guide (patient-specific instrument that was fitted to a unique position on the tibia was manufactured by rapid prototyping. A second instrument was manufactured to adjust the bone allograft to fit the resection gap accurately. Pathologic evaluation of the resected specimens showed tumor-free resection margins in all four cases. The technologies described in this paper may improve the surgical accuracy and patient safety in surgical oncology. In addition, these techniques may decrease operating time and allow for reconstruction with a well-matched allograft to obtain stable osteosynthesis.

  6. Placement of fin type dental implant in three different surgical situations of alveolar bone

    Directory of Open Access Journals (Sweden)

    Coen Pramono D


    Full Text Available Three different dental implant placements according to surgical implant bed situations were observed in its bone integration 3 months after dental implant insertion. This observation was done on implant system which has plateau or fin system. Elf implants were placed in the upper jaw in two patients. In case one, two implants were inserted immediately after tooth extraction, and the other six implants were placed in the alveolar crest regions in delayed implantation or in which the teeth had been extracted over 6 months of period. In case two, three implants were inserted in the post trauma region in the anterior maxilla, which the labial plate had been lost and reconstructed with bone grafting procedure using a mixture of alloplastic and autogenous bones. The alveolar reconstruction was needed to be performed due to only thin alveolar crest width was left intact. All of those implants observed showed in good integration.

  7. Use of 3D Printed Bone Plate in Novel Technique to Surgically Correct Hallux Valgus Deformities (United States)

    Smith, Kathryn E.; Dupont, Kenneth M.; Safranski, David L.; Blair, Jeremy; Buratti, Dawn; Zeetser, Vladimir; Callahan, Ryan; Lin, Jason; Gall, Ken


    Three-dimensional (3-D) printing offers many potential advantages in designing and manufacturing plating systems for foot and ankle procedures that involve small, geometrically complex bony anatomy. Here, we describe the design and clinical use of a Ti-6Al-4V ELI bone plate (FastForward™ Bone Tether Plate, MedShape, Inc., Atlanta, GA) manufactured through 3-D printing processes. The plate protects the second metatarsal when tethering suture tape between the first and second metatarsals and is a part of a new procedure that corrects hallux valgus (bunion) deformities without relying on doing an osteotomy or fusion procedure. The surgical technique and two clinical cases describing the use of this procedure with the 3-D printed bone plate are presented within. PMID:28337049

  8. Use of 3D Printed Bone Plate in Novel Technique to Surgically Correct Hallux Valgus Deformities. (United States)

    Smith, Kathryn E; Dupont, Kenneth M; Safranski, David L; Blair, Jeremy; Buratti, Dawn; Zeetser, Vladimir; Callahan, Ryan; Lin, Jason; Gall, Ken


    Three-dimensional (3-D) printing offers many potential advantages in designing and manufacturing plating systems for foot and ankle procedures that involve small, geometrically complex bony anatomy. Here, we describe the design and clinical use of a Ti-6Al-4V ELI bone plate (FastForward™ Bone Tether Plate, MedShape, Inc., Atlanta, GA) manufactured through 3-D printing processes. The plate protects the second metatarsal when tethering suture tape between the first and second metatarsals and is a part of a new procedure that corrects hallux valgus (bunion) deformities without relying on doing an osteotomy or fusion procedure. The surgical technique and two clinical cases describing the use of this procedure with the 3-D printed bone plate are presented within.

  9. Clinical Outcome of a Wide-diameter Bone-anchored Hearing Implant and a Surgical Technique With Tissue Preservation

    DEFF Research Database (Denmark)

    Mowinckel, Marius S; Møller, Martin N; Wielandt, Kirsten N


    OBJECTIVE: To investigate the clinical outcome of a surgical technique with tissue preservation for a wide bone-anchored hearing implant concerning postoperative complications, skin reactions, implant loss, and implant stability. STUDY DESIGN: Consecutive, prospective case series. SETTING: Tertia...

  10. Does Simulated Spaceflight Modify Epigenetic Status During Bone Remodeling? (United States)

    Thomas, Nicholas J.; Stevick, Rebecca J.; Tran, Luan H.; Nalavadi, Mohit O.; Almeida, Eduardo A.C.; Globus, Ruth K.; Alwood, Joshua S.


    Little is known about the effects of spaceflight conditions on epigenetics. The term epigenetics describes changes to the genome that can affect expression of a gene without changes to the sequence of DNA. Epigenetic processes are thought to underlie cellular differentiation, where transcription of specific genes occurs in response to key stimuli, and may be heritable - passing from one cell to its daughter cell. We hypothesize that the mechanical environment during spaceflight, namely microgravity-induced weightlessness or exercise regulate gene expression in the osteoblast-lineage cells both to control bone formation by osteoblasts and bone resorption by osteoclasts, which continually shapes bone structure throughout life. Similarly we intend to evaluate how radiation regulates these same bone cell activity and differentiation related genes. We further hypothesize that the regulation in bone cell gene expression is at least partially controlled through epigenetic mechanisms of methylation or small non-coding RNA (microRNAs). We have acquired preliminary data suggesting that global genome methylation is modified in response to axial compression of the tibia - a model of exercise. We intend to pursue these hypotheses wherein we will evaluate changes in gene expression and, congruently, changes in epigenetic state in bones from mice subjected to the aforementioned conditions: hindlimb unloading to simulate weightlessness, axial compression of the tibia, or radiation exposure in order to gain insight into the role of epigenetics in spaceflight-induced bone loss.

  11. Assessing suturing techniques using a virtual reality surgical simulator. (United States)

    Kazemi, Hamed; Rappel, James K; Poston, Timothy; Hai Lim, Beng; Burdet, Etienne; Leong Teo, Chee


    Advantages of virtual-reality simulators surgical skill assessment and training include more training time, no risk to patient, repeatable difficulty level, reliable feedback, without the resource demands, and ethical issues of animal-based training. We tested this for a key subtask and showed a strong link between skill in the simulator and in reality. Suturing performance was assessed for four groups of participants, including experienced surgeons and naive subjects, on a custom-made virtual-reality simulator. Each subject tried the experiment 30 times using five different types of needles to perform a standardized suture placement task. Traditional metrics of performance as well as new metrics enabled by our system were proposed, and the data indicate difference between trained and untrained performance. In all traditional parameters such as time, number of attempts, and motion quantity, the medical surgeons outperformed the other three groups, though differences were not significant. However, motion smoothness, penetration and exit angles, tear size areas, and orientation change were statistically significant in the trained group when compared with untrained group. This suggests that these parameters can be used in virtual microsurgery training.

  12. Simulation-based planning of surgical interventions in pediatric cardiology (United States)

    Marsden, Alison


    Hemodynamics plays an essential role in the progression and treatment of cardiovascular disease. This is particularly true in pediatric cardiology, due to the wide variation in anatomy observed in congenital heart disease patients. While medical imaging provides increasingly detailed anatomical information, clinicians currently have limited knowledge of important fluid mechanical parameters. Treatment decisions are therefore often made using anatomical information alone, despite the known links between fluid mechanics and disease progression. Patient-specific simulations now offer the means to provide this missing information, and, more importantly, to perform in-silico testing of new surgical designs at no risk to the patient. In this talk, we will outline the current state of the art in methods for cardiovascular blood flow simulation and virtual surgery. We will then present new methodology for coupling optimization with simulation and uncertainty quantification to customize treatments for individual patients. Finally, we will present examples in pediatric cardiology that illustrate the potential impact of these tools in the clinical setting.

  13. The SEP "Robot": A Valid Virtual Reality Robotic Simulator for the Da Vinci Surgical System?

    NARCIS (Netherlands)

    van der Meijden, O. A. J.; Broeders, I. A. M. J.; Schijven, M. P.


    The aim of the study was to determine if the concept of face and construct validity may apply to the SurgicalSim Educational Platform (SEP) "robot" simulator. The SEP robot simulator is a virtual reality (VR) simulator aiming to train users on the Da Vinci Surgical System. To determine the SEP's

  14. Design-Based Comparison of Spine Surgery Simulators: Optimizing Educational Features of Surgical Simulators. (United States)

    Ryu, Won Hyung A; Mostafa, Ahmed E; Dharampal, Navjit; Sharlin, Ehud; Kopp, Gail; Jacobs, W Bradley; Hurlbert, R John; Chan, Sonny; Sutherland, Garnette R


    Simulation-based education has made its entry into surgical residency training, particularly as an adjunct to hands-on clinical experience. However, one of the ongoing challenges to wide adoption is the capacity of simulators to incorporate educational features required for effective learning. The aim of this study was to identify strengths and limitations of spine simulators to characterize design elements that are essential in enhancing resident education. We performed a mixed qualitative and quantitative cohort study with a focused survey and interviews of stakeholders in spine surgery pertaining to their experiences on 3 spine simulators. Ten participants were recruited spanning all levels of training and expertise until qualitative analysis reached saturation of themes. Participants were asked to perform lumbar pedicle screw insertion on 3 simulators. Afterward, a 10-item survey was administrated and a focused interview was conducted to explore topics pertaining to the design features of the simulators. Overall impressions of the simulators were positive with regards to their educational benefit, but our qualitative analysis revealed differing strengths and limitations. Main design strengths of the computer-based simulators were incorporation of procedural guidance and provision of performance feedback. The synthetic model excelled in achieving more realistic haptic feedback and incorporating use of actual surgical tools. Stakeholders from trainees to experts acknowledge the growing role of simulation-based education in spine surgery. However, different simulation modalities have varying design elements that augment learning in distinct ways. Characterization of these design characteristics will allow for standardization of simulation curricula in spinal surgery, optimizing educational benefit. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Three Dimensional Finite Element Analysis of Stress Distribution and Displacement of the Maxilla Following Surgically Assisted Rapid Maxillary Expansion with Tooth- and Bone-Borne Devices

    Directory of Open Access Journals (Sweden)

    Mohsen Dalband


    Full Text Available Objectives: The aim of this study was to investigate the displacement and stress distri- bution during surgically assisted rapid maxillary expansion under different surgical conditions with tooth- and bone-borne devices.Materials and Methods: Three-dimensional (3D finite element model of a maxilla was constructed and an expansion force of 100 N was applied to the left and right molars and premolars with tooth-borne devices and the left and right of mid-palatal sutures at the first molar level with bone-borne devices. Five CAD models were simulated as fol- lows and surgical procedures were used:  G1: control group (without surgery; G2: Le Fort I osteotomy; G3: Le Fort I osteotomy and para-median osteotomy; G4: Le Fort I osteotomy and pterygomaxillary separation; and G5: Le Fort I osteotomy, para-median osteotomy, and pterygomaxillary separation.Results: Maxillary displacement showed a gradual increase from group 1 to group 5 in all three planes of space, indicating that Le Fort I osteotomy combined with para-me- dian osteotomy and pterygomaxillary separation produced the greatest displacement of the maxilla with both bone- and tooth-borne devices. Surgical relief and bone-borne devices resulted in significantly reduced stress on anchored teeth.Conclusion: Combination of Le Fort I and para-median osteotomy with pterygomaxil-lary separation seems to be an effective procedure for increasing maxillary expansion, and excessive stress side effects are lowered around the anchored teeth with the use of bone-borne devices.

  16. Bone Reduction to Facilitate Immediate Implant Placement and Loading Using CAD/CAM Surgical Guides for Patients With Terminal Dentition. (United States)

    Alzoubi, Fawaz; Massoomi, Nima; Nattestad, Anders


    The aim of this study is to present a method, using 3 computer-aided design/computer-aided manufacturing (CAD/CAM) surgical guides, to accurately obtain the desired bone reduction followed by immediate implant placements and loading for patients diagnosed with terminal dentition. Patients who had bone reduction, implants placed, and immediate loading using Anatomage Invivo 5 CAD/CAM surgical guides between the period 2013 and 2015 were evaluated retrospectively. Patients diagnosed with terminal dentition and treated using the "3-guide technique" were identified. Pre- and postsurgical images were superimposed to evaluate deviations of the bone reduction and deviations at the crest, apex, and angle of implants placed. Twenty-six implants placed in 5 patients were included in this study. The overall deviation means measured for bone reduction was 1.98 mm. The overall deviation means measured for implant placement at the crest, apex, and angle were 1.43 mm, 1.90 mm, and 4.14°, respectively. The CAD/CAM surgical guide fabrication is an emerging tool that may facilitate the surgical process and aid in safe and predictable execution of bone reduction and immediate implant placement. Using 3 CAD/CAM surgical guides, a method is presented to obtain the desired bone reduction followed by immediate implant placement and loading for patients diagnosed with terminal dentition. This method may improve guide stability for patients with terminal dentition undergoing complete implant-supported treatment by taking advantage of the teeth to be extracted.

  17. Assessment of simulated mandibular condyle bone lesions by cone beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Alexandre Perez; Perrella, Andreia; Arita, Emiko Saito; Pereira, Marlene Fenyo Soeiro de Matos; Cavalcanti, Marcelo de Gusmao Paraiso, E-mail: [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Odontologia. Dept. de Estomatologia


    There are many limitations to image acquisition, using conventional radiography, of the temporomandibular joint (TMJ) region. The Computed Tomography (CT) scan is a better option, due to its higher accuracy, for purposes of diagnosis, surgical planning and treatment of bone injuries. The aim of the present study was to analyze two protocols of cone beam computed tomography for the evaluation of simulated mandibular condyle bone lesions. Spherical lesions were simulated in 30 dry mandibular condyles, using dentist drills and drill bits sizes 1, 3 and 6. Each of the mandibular condyles was submitted to cone beam computed tomography (CBCT) using two protocols: axial, coronal and sagittal multiplanar reconstruction (MPR); and sagittal plus coronal slices throughout the longitudinal axis of the mandibular condyles. For these protocols, 2 observers analyzed the CBCT images independently, regarding the presence or not of injuries. Only one of the observers, however, performed on 2 different occasions. The results were compared to the gold standard, evaluating the percentage of agreement, degree of accuracy of CBCT protocols and observers' examination. The z test was used for the statistical analysis. The results showed there were no statistically significant differences between the 2 protocols. There was greater difficulty in the assessment of small-size simulated lesions (drill no.1). From the results of this study, it can be concluded that CBCT is an accurate tool for analyzing mandibular condyle bone lesions, with the MPR protocol showing slightly better results than the sagittal plus coronal slices throughout the longitudinal axis. (author)

  18. Assessment of simulated mandibular condyle bone lesions by cone beam computed tomography

    International Nuclear Information System (INIS)

    Marques, Alexandre Perez; Perrella, Andreia; Arita, Emiko Saito; Pereira, Marlene Fenyo Soeiro de Matos; Cavalcanti, Marcelo de Gusmao Paraiso


    There are many limitations to image acquisition, using conventional radiography, of the temporomandibular joint (TMJ) region. The Computed Tomography (CT) scan is a better option, due to its higher accuracy, for purposes of diagnosis, surgical planning and treatment of bone injuries. The aim of the present study was to analyze two protocols of cone beam computed tomography for the evaluation of simulated mandibular condyle bone lesions. Spherical lesions were simulated in 30 dry mandibular condyles, using dentist drills and drill bits sizes 1, 3 and 6. Each of the mandibular condyles was submitted to cone beam computed tomography (CBCT) using two protocols: axial, coronal and sagittal multiplanar reconstruction (MPR); and sagittal plus coronal slices throughout the longitudinal axis of the mandibular condyles. For these protocols, 2 observers analyzed the CBCT images independently, regarding the presence or not of injuries. Only one of the observers, however, performed on 2 different occasions. The results were compared to the gold standard, evaluating the percentage of agreement, degree of accuracy of CBCT protocols and observers' examination. The z test was used for the statistical analysis. The results showed there were no statistically significant differences between the 2 protocols. There was greater difficulty in the assessment of small-size simulated lesions (drill no.1). From the results of this study, it can be concluded that CBCT is an accurate tool for analyzing mandibular condyle bone lesions, with the MPR protocol showing slightly better results than the sagittal plus coronal slices throughout the longitudinal axis. (author)

  19. Hyperparathyroidism with Bone Tumor-Like Presentation, Approach for Diagnosis and Surgical Intervention

    International Nuclear Information System (INIS)

    Hussein, H.A.; Mebeed, A.H.; Saber, T.Kh.; Farhat, I.G.


    occurred in 2 cases during follow-up (5.2%). Postoperative sever hypocalcemia occurred in 4 cases necessitating longer hospitalization and longer period of oral calcium. Healing in cortical bone was faster than cancellous bone. Conclusion: Hyperparathyroidism should be suspected in all cases with bone tumor-like presentation or even in earlier disease complain of bony or muscle aches. Intact P.T.H and calcium (total and ionic), renal functions, 24 hours urine calcium, neck ultrasonography, and Tc 99m pertechnitate/Tc 99m sestsmibi subtraction scan can establish the diagnosis. Surgical treatment with unilateral approach or bilateral when indicated with intraoperative ultrasound localization, frozen section examination and assessment of intraoperative 10 minutes-P.T.H is very successful with minimal rate of recurrence and complications.

  20. Surgical repair of mid-body proximal sesamoid bone fractures in 25 horses. (United States)

    Busschers, Evita; Richardson, Dean W; Hogan, Patricia M; Leitch, Midge


    To describe the characteristics of unilateral mid-body proximal sesamoid bone (PSB) fractures, to determine factors associated with the outcome of horses after surgical repair, and to describe a technique for arthroscopically assisted screw fixation in lag fashion. Retrospective case series. Horses (n=25) with unilateral mid-body PSB fracture. Medical records (1996-2006), radiographs, and arthroscopic videos of horses with surgically repaired unilateral mid-body PSB fractures were reviewed. Retrieved data included signalment, affected limb and PSB, fracture characteristics, and surgical technique. Outcome was established by radiographic assessment of healing and race records; categorical data were analyzed using Fisher's Exact test. Medial forelimb PSBs were most commonly affected (80%). Surgical technique and degree of reduction were significantly associated with outcome; 44% of horses with screw repair and none of the horses with wire fixation raced (P=.047). Factors that may have influenced this outcome were differences in fracture reduction (improved reduction in 22% wire repairs and 88% screw repairs, P=.002) and use of external coaptation (22% wire repair and 88% lag screw repair, P=.002). None of the horses with unimproved reduction raced after surgery. Only 28% of horses with mid-body PSB fractures raced after surgery. Compared with wire fixation, screw fixation in lag fashion resulted in good reduction and is seemingly a superior repair technique. For mid-body PSB fractures, arthroscopically assisted screw fixation in lag fashion and external coaptation for anesthesia recovery and initial support provides the best likelihood of return to athletic use.

  1. Modeling of tool-tissue interactions for computer-based surgical simulation: a literature review

    NARCIS (Netherlands)

    Misra, Sarthak; Ramesh, K.T.; Okamura, Allison M.


    Surgical simulators present a safe and potentially effective method for surgical training, and can also be used in robot-assisted surgery for pre- and intra-operative planning. Accurate modeling of the interaction between surgical instruments and organs has been recognized as a key requirement in

  2. Systematic video game training in surgical novices improves performance in virtual reality endoscopic surgical simulators: a prospective randomized study. (United States)

    Schlickum, Marcus Kolga; Hedman, Leif; Enochsson, Lars; Kjellin, Ann; Felländer-Tsai, Li


    Previous studies have shown a correlation between previous video game experience and performance in minimally invasive surgical simulators. The hypothesis is that systematic video game training with high visual-spatial demands and visual similarity to endoscopy would show a transfer effect on performance in virtual reality endoscopic surgical simulation. A prospective randomized study was performed. Thirty surgical novices were matched and randomized to five weeks of systematic video game training in either a first-person shooter game (Half Life) with high visual-spatial demands and visual similarities to endoscopy or a video game with mainly cognitive demands (Chessmaster). A matched control group (n = 10) performed no video game training during five weeks. Performance in two virtual reality endoscopic surgical simulators (MIST-VR and GI Mentor II) was measured pre- and post-training. Before simulator training we also controlled for students' visual-spatial ability, visual working memory, age, and previous video game experience. The group training with Half Life showed significant improvement in two GI Mentor II variables and the MIST-VR task MD level medium. The group training with Chessmaster only showed an improvement in the MIST-VR task. No effect was observed in the control group. As recently shown in other studies, current and previous video game experience was important for simulator performance. Systematic video game training improved surgical performance in advanced virtual reality endoscopic simulators. The transfer effect increased when increasing visual similarity. The performance in intense, visual-spatially challenging video games might be a predictive factor for the outcome in surgical simulation.

  3. Clinical Outcomes of Surgical Treatments for Primary Malignant Bone Tumors Arising in the Acetabulum

    Directory of Open Access Journals (Sweden)

    Tomohiro Fujiwara


    Full Text Available The functional and oncologic results of eighteen patients with primary malignant periacetabular tumors were reviewed to determine the impact of surgical treatment. The reconstruction procedures were endoprosthesis (11, hip transposition (4, iliofemoral arthrodesis (2, and frozen bone autograft (1. After a mean follow-up of 62 months, 13 patients were alive and 5 had died of their disease; the 5-year overall survival rate was 67.2%. The corresponding mean MSTS scores of patients with endoprosthesis (11 and other reconstructions (7 were 42% and 55% (49%, 68%, and 50%, respectively. Overall, postoperative complications including deep infection or dislocation markedly worsened the functional outcome. Iliofemoral arthrodesis provided better function than the other procedures, whereas endoprosthetic reconstruction demonstrated poor functional outcome except for patients who were reconstructed with the adequate soft tissue coverage. Avoiding postoperative complications is highly important for achieving better function, suggesting that surgical procedures with adequate soft tissue coverage or without the massive use of nonbiological materials are preferable. Appropriate selection of the reconstructive procedures for individual patients, considering the amount of remaining bone and soft tissues, would lead to better clinical outcomes.

  4. Finite element simulation of Reference Point Indentation on bone. (United States)

    Idkaidek, Ashraf; Agarwal, Vineet; Jasiuk, Iwona


    Reference Point Indentation (RPI) is a novel technique aimed to assess bone quality. Measurements are recorded by the BioDent instrument that applies multiple indents to the same location of cortical bone. Ten RPI parameters are obtained from the resulting force-displacement curves. Using the commercial finite element analysis software Abaqus, we assess the significance of the RPI parameters. We create an axisymmetric model and employ an isotropic viscoelastic-plastic constitutive relation with damage to simulate indentations on a human cortical bone. Fracture of bone tissue is not simulated for simplicity. The RPI outputs are computed for different simulated test cases and then compared with experimental results, measured using the BioDent, found in literature. The number of cycles, maximum indentation load, indenter tip radius, and the mechanical properties of bone: Young׳s modulus, compressive yield stress, and viscosity and damage constants, are varied. The trends in the RPI parameters are then investigated. We find that the RPI parameters are sensitive to the mechanical properties of bone. An increase in Young׳s modulus of bone causes the force-displacement loading and unloading slopes to increase and the total indentation distance (TID) to decrease. The compressive yield stress is inversely proportional to a creep indentation distance (CID1) and the TID. The viscosity constant is proportional to the CID1 and an average of the energy dissipated (AvED). The maximum indentation load is proportional to the TID, CID1, loading and unloading slopes, and AvED. The damage parameter is proportional to the TID, but it is inversely proportional to both the loading and unloading slopes and the AvED. The value of an indenter tip radius is proportional to the CID1 and inversely proportional to the TID. The number of load cycles is inversely proportional to an average of a creep indentation depth (AvCID) and the AvED. The indentation distance increase (IDI) is strongly

  5. Artificial Gravity as a Bone Loss Countermeasure in Simulated Weightlessness (United States)

    Smith, S. M.; Zwart, S. R.; Crawford, G. E.; Gillman, P. L.; LeBlanc, A.; Shackelford, L. C.; Heer, M. A.


    The impact of microgravity on the human body is a significant concern for space travelers. We report here initial results from a pilot study designed to explore the utility of artificial gravity (AG) as a countermeasure to the effects of microgravity, specifically to bone loss. After an initial phase of adaptation and testing, 15 male subjects underwent 21 days of 6 head-down bed rest to simulate the deconditioning associated with space flight. Eight of the subjects underwent 1 h of centrifugation (AG, 1 gz at the heart, 2.5 gz at the feet) each day for 21 days, while 7 of the subjects served as untreated controls (CN). Blood and urine were collected before, during, and after bed rest for bone marker determinations. At this point, preliminary data are available on the first 8 subjects (6 AG, and 2 CN). Comparing the last week of bed rest to before bed rest, urinary excretion of the bone resorption marker n-telopeptide increased 95 plus or minus 59% (mean plus or minus SD) in CN but only 32 plus or minus 26% in the AG group. Similar results were found for another resorption marker, helical peptide (increased 57 plus or minus 0% and 35 plus or minus 13% in CN and AG respectively). Bone-specific alkaline phosphatase, a bone formation marker, did not change during bed rest. At this point, sample analyses are continuing, including calcium tracer kinetic studies. These initial data demonstrate the potential effectiveness of short-radius, intermittent AG as a countermeasure to the bone deconditioning that occurs during bed rest.

  6. [Is local bone graft sufficient to maintain the surgical correction in adolescent idiopathic scoliosis curves?]. (United States)

    Mardomingo, A; Sánchez-Mariscal, F; Alvarez, P; Pizones, J; Zúñica, L; Izquierdo, E


    The purpose of this study was to compare postoperative clinical and radiological results in adolescent idiopathic scoliosis curves treated by posterior arthrodesis using autogenous bone graft from iliac crest (CI) versus only local autograft bone (HL). A retrospective matched cohort study was conducted on 73 patients (CI n=37 and HL n=36) diagnosed with adolescent idiopathic scoliosis and treated surgically by posterior arthrodesis. The mean post-operative follow-up was 126 months in the CI group vs. 66 months in the HL group. The radiographic data collected consisted of preoperative, postoperative, and final follow-up antero-posterior and lateral full-length radiographs. Loss of correction and quality of arthrodesis were evaluated by comparing the scores obtained from the Spanish version of the SRS-22 questionnaire. There were significant differences in the post-operative results as regards the correction of the Cobb angle of the main curve (HL 61 ± 15% vs. CI 51 ± 14%, P<.004), however a greater loss of correction was found in the local bone group (CI 4.5 ± 7.3° vs. HL 8.5 ± 6.3°, P=.02). There were no significant differences as regards the correction of the Cobb angle of the main curve at the end of follow-up. There were no clinical differences between the two groups in the SRS-22 scores. At 5 years of follow-up, there was a statistically significant greater loss of radiographic correction at the end of final follow-up in the local bone graft group. However clinical differences were not observed as regards the SRS-22 scores. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  7. Notes From the Field: Secondary Task Precision for Cognitive Load Estimation During Virtual Reality Surgical Simulation Training. (United States)

    Rasmussen, Sebastian R; Konge, Lars; Mikkelsen, Peter T; Sørensen, Mads S; Andersen, Steven A W


    Cognitive load (CL) theory suggests that working memory can be overloaded in complex learning tasks such as surgical technical skills training, which can impair learning. Valid and feasible methods for estimating the CL in specific learning contexts are necessary before the efficacy of CL-lowering instructional interventions can be established. This study aims to explore secondary task precision for the estimation of CL in virtual reality (VR) surgical simulation and also investigate the effects of CL-modifying factors such as simulator-integrated tutoring and repeated practice. Twenty-four participants were randomized for visual assistance by a simulator-integrated tutor function during the first 5 of 12 repeated mastoidectomy procedures on a VR temporal bone simulator. Secondary task precision was found to be significantly lower during simulation compared with nonsimulation baseline, p impact on secondary task precision. This finding suggests that even though considerable changes in CL are reflected in secondary task precision, it lacks sensitivity. In contrast, secondary task reaction time could be more sensitive, but requires substantial postprocessing of data. Therefore, future studies on the effect of CL modifying interventions should weigh the pros and cons of the various secondary task measurements. © The Author(s) 2015.

  8. Evaluation of Efficacy of Surgical Periodontal Therapy with the Use of Bone Graft in the Treatment of Periodontal Intrabony Defects. (United States)

    Gojkov-Vukelic, Mirjana; Hadzic, Sanja; Pasic, Enes


    One of the most important goals of periodontitis therapy is the elimination of deep periodontal pockets. In regenerative periodontal therapy, different types of bone grafts, membranes, growth factors, etc. are used to improve regeneration of lost periodontal tissue. The aim of this study was to evaluate the effect of surgical therapy supported by the use of bone replacement material in the treatment of deep intrabony pockets, compared to surgical treatment (flap surgery) without the use of bone replacement in advanced periodontitis. The study included 50 patients of both sexes with advanced periodontitis, divided into two groups. After initial periodontal therapy was performed, plaque index (PI), papillary bleeding index (PBI) were verified, and depth of periodontal pockets was measured in both groups. One group (group 1) of the patients underwent surgical therapy, open flap surgery, while the other group (group 2) underwent the same surgical treatment method (open flap surgery), during which bone defects were filled with bone replacement material. The results showed that both group 1 and group 2 experienced improvements after periodontal surgical therapy. In group 1, there are no statistically significant changes in all three plaque index measurements (PI), while there has been a significant reduction in PI in group 2 following the surgery. For the PBI index, it was determined that there were statistically significant changes in values in group 1, both after surgical procedures and six months later, as well as in group 2. Statistical analysis of the results of the probing depth of pockets has shown that there are significant changes in the measurement of the depth of periodontal pocket one month after the surgery, as well as six months later, meaning that there has been a significant reduction in the depth of the periodontal pocket one month following the surgery as well as six months later, for both groups. However, we did not determine a statistically

  9. One-piece implants: placement timing, surgical technique, loading protocol, and marginal bone loss. (United States)

    Prithviraj, D R; Gupta, Vikas; Muley, Ninad; Sandhu, Pushpinder


    Osseointegration being an accepted and well-documented concept, attention is now directed towards simplification of the mechanical design of implants and towards achieving biomechanical success. The aim of this literature review is to provide an overview of the one-piece implant, with its advantages and disadvantages over a conventional two-piece implant. The PubMed database was searched in the English language using the keywords one-piece implant, single-piece implant, single-stage implant surgery, and two-piece implant. Articles were selected on the basis of whether they had sufficient information related to placement timing, surgical procedure used, loading protocol, follow-up periods, marginal bone loss, and implant success rates of one-piece implants. For inclusion, a study group must have had a minimum of 30 one-piece implants followed for at least 1 year. Nineteen articles were subjected to the selection criteria. Out of 19 clinical trials only 11 met the selection criteria. Five parameters were taken into consideration for studying one-piece implants: placement timing, surgical technique, loading protocol, marginal bone loss, and implant survival rate. The data from the identified studies were tabulated according to these parameters and discussed. Delayed placement of one-piece implants is more commonly practiced than extraction and immediate placement. Most surgeons prefer surgeries using flaps as compared to flapless surgeries, and in most cases, one-piece implants were loaded immediately. Limited literature reveals both positive and negative results regarding the effect of a one-piece implant system on surrounding hard and soft tissues. © 2012 by the American College of Prosthodontists.

  10. A surgical simulator for planning and performing repair of cleft lips. (United States)

    Schendel, Stephen; Montgomery, Kevin; Sorokin, Andrea; Lionetti, Giancarlo


    The objective of this project was to develop a computer-based surgical simulation system for planning and performing cleft lip repair. This system allows the user to interact with a virtual patient to perform the traditional steps of cleft-lip repair (rotation-advancement technique). The system interfaces to force-feedback (haptic) devices to track the user's motion and provide feedback during the procedure, while performing real-time soft-tissue simulation. An 11-day-old unilateral cleft lip, alveolus and palate patient was previously CT scanned for ancillary diagnostic purposes using standard imaging protocols and 1mm slices. High-resolution 3D meshes were automatically generated from this data using the ROVE software developed in-house. The resulting 3D meshes of bone and soft tissue were instilled with physical properties of soft tissues for purposes of simulation. Once these preprocessing steps were completed, the patient's bone and soft tissue data are presented on the computer screen in stereo and the user can freely view, rotate, and otherwise interact with the patient's data in real time. The user is prompted to select anatomical landmarks on the patient's data for preoperative planning purposes, then their locations are compared against that of a 'gold standard' and a score, derived from their deviation from that standard and time required, is generated. The user can then move a haptic stylus and guide the motion of the virtual cutting tool. The soft tissues can thus be incised using this virtual cutting tool, moved using virtual forceps, and fused in order to perform any of the major procedures for cleft lip repair. Real-time soft tissue deformation of the mesh realistically simulates normal tissues and haptic-rate (>1 kHz) force-feedback is provided. The surgical result of the procedure can then be immediately visualized and the entire training process can be repeated at will. A short evaluation study was also performed. Two groups (non-medical and

  11. Surgical repair of central slip avulsion injuries with Mitek bone anchor--retrospective analysis of a case series.

    LENUS (Irish Health Repository)

    Chan, Jeffrey C Y


    The purpose of this study is to describe our technique of central slip repair using the Mitek bone anchor and to evaluate the treatment outcome. Eight digits in eight patients were reconstructed using the bone anchor: three little fingers, two middle fingers, two index fingers and one ring finger. There were two immediate and six delayed repairs (range from one day to eight months). Four patients had pre-operative intensive splinting and physiotherapy to restore passive extension of the proximal interphalangeal joint prior to central slip reconstruction. All patients have made good progress since surgery. No patient requires a second procedure and none of the bone anchors have dislodged or loosened. We conclude that the Mitek bone anchor is a reliable technique to achieve soft tissue to bone fixation in central slip avulsion injuries. We recommend that this technique be considered as a treatment option for patients requiring surgical repair.

  12. Local recurrence in giant cell tumor of bone: Comparative study of two methods of surgical approach

    Directory of Open Access Journals (Sweden)

    Khodamorad Jamshidi


    Full Text Available

    • BACKGROUND: Most experts accept the use of curettage, phenol, and cement as the best treatment to prevent recurrence of giant-cell tumors. The purpose of this investigation was to analyze the effect of cement as a filling material and compare it with bone graft and the effect of high-speed burr in local recurrence of giant cell tumor after curettage.
    • METHODS: We retrospectively reviewed 168 consecutive patients diagnosed with giant cell tumor at the three most common sites (distal femur, proximal tibia, and distal radius to determine the pattern of local tumor recurrence. Only patients who had intralesional excision of primary tumor by curettage without a surgical adjuvant were included.
    • RESULTS: A total of 168 patients with primary giant cell tumor were treated with curettage. The female to male ratio was 1.4: 1 and the mean age was 34 years (range: 17-68 years. The minimum follow-up was 24 months and the median follow up was 75 months. The knee region was involved in 135 (80.4% patients. There were 10 (5.9%, 130 (77.4% and 28 (16.7% patients in Campanacci grade I, II and III, respectively. Tumor surgery was supplemented with high speed burring in 88 (52.4%, bone cement in 82 (48.8% and bone grafting, either autograft or allograft in 86 (51.2% patients. The recurrence rates were 18.2% and 37.5% for curettage with or without high speed burring, respectively. For 46 (27% recurrent lesions treated by curettage, the recurrence rate was 35%. The nature of the filling material used did not show any significant impact on the outcome of recurrence rate.
    • CONCLUSIONS: Despite the high rates of recurrence after treatment of giant-cell tumor with curettage, the results of the present study suggested that the high-speed burr is effective in reducing the rate of recurrence. The risk of local recurrence after curettage with a high-speed burr and

    • [Evaluation of early physiotherapy in patients after surgical treatment of cruciate ligament injury by bone-tendon-bone method]. (United States)

      Klupiński, Kamil; Krekora, Katarzyna; Woldańska-Okońska, Marta


      improvement has been obtained in all examined patients after anterior cruciate ligament reconstruction by bone - tendon - bone method at every stage of rehabilitation in relation to the initial values. Early motor physiotherapy has a significant impact on the condition of patients treated both surgically and conservatively. The differences observed between the groups in the range of the measurement of movement in the knee joint, the measurement of musculoskeletal strength, severity of pain in the knee joint, transpatellar anthropometric measurement of the knee joint and linear measurements of the thigh and shin were caused by necessary surgery which leads to the conclusion that the therapeutic rehabilitation should be longer in the investigated group. In this group introduction of physical therapy with analgesic effects is also of importance. Taking into account good results observed in patients from the control group, who were treated conservatively, the possible indications for surgery should be carefully considered.

    • Design, development and implementation of a surgical simulation pathway curriculum for biliary disease. (United States)

      Buchholz, Joseph; Vollmer, Charles M; Miyasaka, Kiyoyuki W; Lamarra, Denise; Aggarwal, Rajesh


      The initial focus of simulation in surgical education was to provide instruction in procedural tasks and technical skills. Recently, the importance of instruction in nontechnical areas, such as communication and teamwork, was realized. On rotation, the surgical resident requires proficiency in both technical and non-technical skills through the entire patient care pathway, i.e., pre-, intra- and postoperatively. The focus was upon implementation of a biliary disease-based surgical simulation curriculum. The cornerstones of this module were clinical care pathway simulation sessions, at the commencement and conclusion of the 3 days. Each resident completed a simulated outpatient encounter with a standardized patient (SP) presenting with biliary colic, performed a laparoscopic cholecystectomy on a porcine model in a simulated operating room and completed an uncomplicated follow-up visit with the same SP. Assessments of resident performance were collected for every pathway scenario using standardized assessment forms approved by the American Board of Surgery. Additional formative sessions included hands-on, didactic and SP encounter sessions. The biliary surgical simulation pathway curriculum was successful implemented over the course of a 3-day, immersive module. The curriculum was delivered within the Penn Medicine Clinical Simulation Center and accommodated six junior surgical resident learners. The curriculum was divided into 4-h sessions, each led by a department faculty member. The cost of the implementation approximated $17,500 (USD). It is imperative that surgical residents undergo simulation training directly linked to their hospital responsibilities so as to provide immediate performance improvement and reduce errors in the clinical environment. This pathway curriculum has successfully shown the feasibility to implement this novel approach to surgical simulation for junior resident training at an academic medical center. Such a patient-focused approach to

    • Influence of surgical drills wear on thermal process generated in bones. (United States)

      Basiaga, Marcin; Paszenda, Zbigniew; Szewczenko, Janusz; Kaczmarek, Marcin


      The influence of the wear rate of drills used in bone surgery on the temperature distribution in the femur models (Sawbones) is presented in the paper. Surgical drills of diameter d = 4.5 mm and diverse edge geometry (90° and 120°) were selected for the study. In order to carry out thermal analysis with the use of finite element, experimental studies of wear process were necessary. These studies, among others, consisted in determination of average values of axial forces and cutting torques as a function of the number of drilled holes. The study showed an impact of the drill geometry on values that describe cutting process. It was found that the greatest values of torques and axial cutting forces occur in drills of point angle of 120°. Next, in order to determine the effect of wear rate on the generation of temperature in the cutting zone, thermal analysis of the drilling process using the finite element method was carried out. It was found that higher temperatures in the bone are observed for drilling with the use of the drill of point angle equal to 120°, as in the experimental study. For the tools of such edge geometry the wear of cutting edge is more intensive and the generated temperature in femur for the wear land VBB = 0.32 mm has reached the critical value associated with the process of thermal necrosis.

    • Mastering surgical skills through simulation-based learning: Practice makes one perfect

      Directory of Open Access Journals (Sweden)

      Niti Khunger


      Full Text Available Simulation-based learning in surgery is a learning model where an environment similar to real life surgical situation is created for the trainee to learn various surgical skills. It can be used to train a new operator as well to assess his skills. This methodology helps in repetitive practice of surgical skills on nonliving things so that the operator can be near-perfect when operating on a live patient. Various models are available for learning different dermatosurgery skills.

    • Mastering Surgical Skills Through Simulation-Based Learning: Practice Makes One Perfect. (United States)

      Khunger, Niti; Kathuria, Sushruta


      Simulation-based learning in surgery is a learning model where an environment similar to real life surgical situation is created for the trainee to learn various surgical skills. It can be used to train a new operator as well to assess his skills. This methodology helps in repetitive practice of surgical skills on nonliving things so that the operator can be near-perfect when operating on a live patient. Various models are available for learning different dermatosurgery skills.

    • The use of first stage bone augmentation screws to stabilize the surgical template in the second stage.

      NARCIS (Netherlands)

      Verhamme, L.M.; Meijer, G.J.; Berge, S.J.; Maal, T.J.J.


      A new method is presented in which the osteosynthesis screws from a first stage bone augmentation of the maxilla are used to stabilize the surgical template during implant placement in the second stage. This method was evaluated in one patient and the results compared to those of previous studies.

    • The use of first stage bone augmentation screws to stabilize the surgical template in the second stage

      NARCIS (Netherlands)

      Verhamme, L. M.; Meijer, G. J.; Bergé, S. J.; Maal, T. J J


      A new method is presented in which the osteosynthesis screws from a first stage bone augmentation of the maxilla are used to stabilize the surgical template during implant placement in the second stage. This method was evaluated in one patient and the results compared to those of previous studies.

    • Arthroscopic Shoulder Surgical Simulation Training Curriculum: Transfer Reliability and Maintenance of Skill Over Time. (United States)

      Dunn, John C; Belmont, Philip J; Lanzi, Joseph; Martin, Kevin; Bader, Julia; Owens, Brett; Waterman, Brian R


      Surgical education is evolving as work hour constraints limit the exposure of residents to the operating room. Potential consequences may include erosion of resident education and decreased quality of patient care. Surgical simulation training has become a focus of study in an effort to counter these challenges. Previous studies have validated the use of arthroscopic surgical simulation programs both in vitro and in vivo. However, no study has examined if the gains made by residents after a simulation program are retained after a period away from training. In all, 17 orthopedic surgery residents were randomized into simulation or standard practice groups. All subjects were oriented to the arthroscopic simulator, a 14-point anatomic checklist, and Arthroscopic Surgery Skill Evaluation Tool (ASSET). The experimental group received 1 hour of simulation training whereas the control group had no additional training. All subjects performed a recorded, diagnostic arthroscopy intraoperatively. These videos were scored by 2 blinded, fellowship-trained orthopedic surgeons and outcome measures were compared within and between the groups. After 1 year in which neither group had exposure to surgical simulation training, all residents were retested intraoperatively and scored in the exact same fashion. Individual surgical case logs were reviewed and surgical case volume was documented. There was no difference between the 2 groups after initial simulation testing and there was no correlation between case volume and initial scores. After training, the simulation group improved as compared with baseline in mean ASSET (p = 0.023) and mean time to completion (p = 0.01). After 1 year, there was no difference between the groups in any outcome measurements. Although individual technical skills can be cultivated with surgical simulation training, these advancements can be lost without continued education. It is imperative that residency programs implement a simulation curriculum and

  1. Reconstruction of a Severely Atrophied Alveolar Ridge by Computer-Aided Gingival Simulation and 3D-Printed Surgical Guide: A Case Report. (United States)

    Song, In-Seok; Lee, Mi-Ran; Ryu, Jae-Jun; Lee, Ui-Lyong


    Dental implants positioned in severely atrophied anterior maxillae require esthetic or functional compromises. This case report describes the rehabilitation of a severely atrophied alveolar ridge with a three-dimensional (3D) computer-aided design/computer-aided manufacture (CAD/CAM) surgical guide. A 50-year-old woman had a severely atrophied anterior maxilla with unfavorably positioned dental implants. Functional and esthetic prosthodontic restoration was difficult to achieve. An anterior segmental osteotomy was planned to reposition the dental implants. A 3D surgical guide was designed for precise relocation of the segment. The surgical guide firmly grasped the impression copings of the dental implants, minimizing surgical errors. Three-dimensional gingival simulation was used preoperatively to estimate the appropriate position of the gingiva. Rigid fixation to the surrounding bone allowed immobilization of the implant-bone segment. Satisfactory esthetic and functional outcomes were attained 6 months after surgery. Finally, a severely atrophied alveolar ridge with unfavorably positioned dental implants was recovered with minimal esthetic and functional deterioration using gingival simulation and a 3D CAD/CAM surgical guide.

  2. Dimensional analysis of the parietal bone in areas of surgical interest and relationship between parietal thickness and cephalic index. (United States)

    de Souza Fernandes, Atson Carlos; Neto, Antonio Irineu Trindade; de Freitas, André Carlos; de Moraes, Márcio


    The aim of this study was to determine the thickness of the parietal bone in bone graft donor sites and to study the relationship between parietal bone thickness and gender or cephalic index. We studied 300 parietal bones from 150 human skulls (84 male and 66 female) from individuals aged 18 to 60 years at the time of death. On each parietal bone, 9 areas were drawn by use of reference anatomic landmarks (bregma, lambda, asterion, and pterion), and bone thickness was determined in the areas adjoining the sagittal suture--superior-anterior (Sa), superior-medial (Sm), and superior-posterior (Sp). Mean thickness measurements ranged from 2.30 to 11.25 mm in the Sa area, from 3.08 to 13.32 mm in the Sm area, and from 2.88 to 12.26 in the Sp area. Smaller mean measurements were observed in the Sa area, with the smallest mean thickness being found in brachycephalic female specimens. The largest mean thickness was also found in female specimens in the Sm area. Statistically significant differences between genders were found only in the Sa area in dolichocephalic and mesocephalic specimens. Although the best bone graft donor site surgically is different in individuals of different genders and with different cephalic indexes, our findings suggest that harvesting from the anterosuperior area of the parietal bone should not be performed. Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  3. Medical Visualization and Simulation for Customizable Surgical Guides

    NARCIS (Netherlands)

    Kroes, T.


    This thesis revolves around the development of medical visualization tools for the planning of CSG-based surgery. To this end, we performed an extensive computerassisted surgery (CAS) literature study, developed a novel optimization technique for customizable surgical guides (CSG), and introduce

  4. American College of Surgeons/Association for Surgical Education medical student simulation-based surgical skills curriculum needs assessment. (United States)

    Glass, Charity C; Acton, Robert D; Blair, Patrice G; Campbell, Andre R; Deutsch, Ellen S; Jones, Daniel B; Liscum, Kathleen R; Sachdeva, Ajit K; Scott, Daniel J; Yang, Stephen C


    Simulation can enhance learning effectiveness, efficiency, and patient safety and is engaging for learners. A survey was conducted of surgical clerkship directors nationally and medical students at 5 medical schools to rank and stratify simulation-based educational topics. Students applying to surgery were compared with others using Wilcoxon's rank-sum tests. Seventy-three of 163 clerkship directors (45%) and 231 of 872 students (26.5%) completed the survey. Of students, 28.6% were applying for surgical residency training. Clerkship directors and students generally agreed on the importance and timing of specific educational topics. Clerkship directors tended to rank basic skills, such as examination skills, higher than medical students. Students ranked procedural skills, such as lumbar puncture, more highly than clerkship directors. Surgery clerkship directors and 4th-year medical students agree substantially about the content of a simulation-based curriculum, although 4th-year medical students recommended that some topics be taught earlier than the clerkship directors recommended. Students planning to apply to surgical residencies did not differ significantly in their scoring from students pursuing nonsurgical specialties. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Transfer of systematic computer game training in surgical novices on performance in virtual reality image guided surgical simulators. (United States)

    Kolga Schlickum, Marcus; Hedman, Leif; Enochsson, Lars; Kjellin, Ann; Felländer-Tsai, Li


    We report on a pilot study that investigates the transfer effect of systematic computer game training on performance in image guided surgery. In a group of 22 surgical novices, subjects were matched and randomized into one group training with a 3-D first person shooter (FPS) game and one group training with a 2-D non-FPS game. We also included a control group. Subjects were tested pre- and post training in the MIST-VR and GI-Mentor surgical simulators. We found that subjects with past experience specific to FPS games were significantly better in performing the simulated endoscopy task, both regarding time and efficiency of screening, compared to subjects lacking FPS game experience. Furthermore subjects who underwent systematic FPS game training performed better in the MIST-VR than those training with a 2-D game. Our findings indicate a transfer effect and that experience of video games are important for training outcome in simulated surgical procedures. Video game training can become useful when designing future skills training curricula for surgeons.

  6. Modeling the Mechanical Consequences of Age-Related Trabecular Bone Loss by XFEM Simulation. (United States)

    Fan, Ruoxun; Gong, He; Zhang, Xianbin; Liu, Jun; Jia, Zhengbin; Zhu, Dong


    The elderly are more likely to suffer from fracture because of age-related trabecular bone loss. Different bone loss locations and patterns have different effects on bone mechanical properties. Extended finite element method (XFEM) can simulate fracture process and was suited to investigate the effects of bone loss on trabecular bone. Age-related bone loss is indicated by trabecular thinning and loss and may occur at low-strain locations or other random sites. Accordingly, several ideal normal and aged trabecular bone models were created based on different bone loss locations and patterns; then, fracture processes from crack initiation to complete failure of these models were observed by XFEM; finally, the effects of different locations and patterns on trabecular bone were compared. Results indicated that bone loss occurring at low-strain locations was more detrimental to trabecular bone than that occurring at other random sites; meanwhile, the decrease in bone strength caused by trabecular loss was higher than that caused by trabecular thinning, and the effects of vertical trabecular loss on mechanical properties were more severe than horizontal trabecular loss. This study provided a numerical method to simulate trabecular bone fracture and distinguished different effects of the possible occurrence of bone loss locations and patterns on trabecular bone.

  7. Modeling the Mechanical Consequences of Age-Related Trabecular Bone Loss by XFEM Simulation

    Directory of Open Access Journals (Sweden)

    Ruoxun Fan


    Full Text Available The elderly are more likely to suffer from fracture because of age-related trabecular bone loss. Different bone loss locations and patterns have different effects on bone mechanical properties. Extended finite element method (XFEM can simulate fracture process and was suited to investigate the effects of bone loss on trabecular bone. Age-related bone loss is indicated by trabecular thinning and loss and may occur at low-strain locations or other random sites. Accordingly, several ideal normal and aged trabecular bone models were created based on different bone loss locations and patterns; then, fracture processes from crack initiation to complete failure of these models were observed by XFEM; finally, the effects of different locations and patterns on trabecular bone were compared. Results indicated that bone loss occurring at low-strain locations was more detrimental to trabecular bone than that occurring at other random sites; meanwhile, the decrease in bone strength caused by trabecular loss was higher than that caused by trabecular thinning, and the effects of vertical trabecular loss on mechanical properties were more severe than horizontal trabecular loss. This study provided a numerical method to simulate trabecular bone fracture and distinguished different effects of the possible occurrence of bone loss locations and patterns on trabecular bone.

  8. Bone Marrow Stem Cells Added to a Hydroxyapatite Scaffold Result in Better Outcomes after Surgical Treatment of Intertrochanteric Hip Fractures

    Directory of Open Access Journals (Sweden)

    Joao Torres


    Full Text Available Introduction. Intertrochanteric hip fractures occur in the proximal femur. They are very common in the elderly and are responsible for high rates of morbidity and mortality. The authors hypothesized that adding an autologous bone marrow stem cells concentrate (ABMC to a hydroxyapatite scaffold and placing it in the fracture site would improve the outcome after surgical fixation of intertrochanteric hip fractures. Material and Methods. 30 patients were randomly selected and divided into 2 groups of 15 patients, to receive either the scaffold enriched with the ABMC (Group A during the surgical procedure, or fracture fixation alone (Group B. Results. There was a statistically significant difference in favor of group A at days 30, 60, and 90 for Harris Hip Scores (HHS, at days 30 and 60 for VAS pain scales, for bedridden period and time taken to start partial and total weight bearing (P<0.05. Discussion. These results show a significant benefit of adding a bone marrow enriched scaffold to surgical fixation in intertrochanteric hip fractures, which can significantly reduce the associated morbidity and mortality rates. Conclusion. Bone marrow stem cells added to a hydroxyapatite scaffold result in better outcomes after surgical treatment of intertrochanteric hip fractures.

  9. Can surgical simulation be used to train detection and classification of neural networks? (United States)

    Zisimopoulos, Odysseas; Flouty, Evangello; Stacey, Mark; Muscroft, Sam; Giataganas, Petros; Nehme, Jean; Chow, Andre; Stoyanov, Danail


    Computer-assisted interventions (CAI) aim to increase the effectiveness, precision and repeatability of procedures to improve surgical outcomes. The presence and motion of surgical tools is a key information input for CAI surgical phase recognition algorithms. Vision-based tool detection and recognition approaches are an attractive solution and can be designed to take advantage of the powerful deep learning paradigm that is rapidly advancing image recognition and classification. The challenge for such algorithms is the availability and quality of labelled data used for training. In this Letter, surgical simulation is used to train tool detection and segmentation based on deep convolutional neural networks and generative adversarial networks. The authors experiment with two network architectures for image segmentation in tool classes commonly encountered during cataract surgery. A commercially-available simulator is used to create a simulated cataract dataset for training models prior to performing transfer learning on real surgical data. To the best of authors' knowledge, this is the first attempt to train deep learning models for surgical instrument detection on simulated data while demonstrating promising results to generalise on real data. Results indicate that simulated data does have some potential for training advanced classification methods for CAI systems.

  10. Surgical management of large segmental femoral and radial bone defects in a dog: through use of a cylindrical titanium mesh cage and a cancellous bone graft. (United States)

    Segal, U; Shani, J


    In this case report, we describe the use of a cylindrical titanium mesh cage combined with cancellous bone graft to surgically manage large segmental bone defects in a dog. A seven-year-old, neutered male cross-breed dog, with highly comminuted fractures of the right femur and the left radius and ulna, was referred for treatment. Previous open reduction and internal fixation of these fractures had failed. Following implant removal and debridement of each bone, a 71 mm segmental femoral defect and a 27 mm segmental radial defect were present. A commercially available cylindrical titanium mesh cage was filled with ss-tricalcium phosphate crystals mixed with an equal volume of autogenous cancellous bone graft. The mesh cage was aligned with the proximal and distal parts of each bone using an intramedullary pin passing through the cage, and a locking plate was applied to the proximal and distal fracture fragments to produce compression against the titanium cage. The dog had a successful long-term clinical outcome, and radiographic examination at 22 and 63 weeks after surgery showed the formation of remodelling bridging callus that was continuous across the titanium cage in each of the fractures. Due to the relative simplicity of the technique and the favourable outcome in this case, it should be considered an option when managing comminuted fractures with large bone defects.

  11. Virtual Reality Simulation as a Tool to Monitor Surgical Performance Indicators: VIRESI Observational Study. (United States)

    Muralha, Nuno; Oliveira, Manuel; Ferreira, Maria Amélia; Costa-Maia, José


    Virtual reality simulation is a topic of discussion as a complementary tool to traditional laparoscopic surgical training in the operating room. However, it is unclear whether virtual reality training can have an impact on the surgical performance of advanced laparoscopic procedures. Our objective was to assess the ability of the virtual reality simulator LAP Mentor to identify and quantify changes in surgical performance indicators, after LAP Mentor training for digestive anastomosis. Twelve surgeons from Centro Hospitalar de São João in Porto (Portugal) performed two sessions of advanced task 5: anastomosis in LAP Mentor, before and after completing the tutorial, and were evaluated on 34 surgical performance indicators. The results show that six surgical performance indicators significantly changed after LAP Mentor training. The surgeons performed the task significantly faster as the median 'total time' significantly reduced (p virtual reality training simulation as a benchmark tool to assess the surgical performance of Portuguese surgeons. LAP Mentor is able to identify variations in surgical performance indicators of digestive anastomosis.

  12. Surgical outcome of bone anchored hearing aid (baha) implant surgery: a 10 years experience. (United States)

    Asma, A; Ubaidah, M A; Hasan, Siti Salbiah; Wan Fazlina, W H; Lim, B Y; Saim, L; Goh, B S


    Bone anchored hearing aid (Baha) implant is an option for patient with canal atresia, single sided deafness(SSD) and chronically discharging ears despite treatments. This retrospective study was conducted from 2001 to 2011 to evaluate the surgical outcome of Baha implant surgery. Thirty-three patients were identified during this study period. Their age at implantation ranged from 5 to 40 years. Of 33 patients, 29 (87.9 %) patients had bilateral microtia and canal atresia, 3 (9.1 %) patients had unilateral microtia and canal atresia and 1 (3.0 %) patients have SSD following labyrinthitis. One patient (3.2 %) had major complication which is lost of implant due to failure of osseointegration. Soft tissue reactions were seen 7 patients (21.1 %). Of these 7 patients, 4 patients required 3-4 procedures as day care operation for excision of the skin overgrowth surrounding the abutment. Recurrent antibiotic treatment was required in 3 patients (9.7 %). None of our patient had history of intraoperative or peri-operative complication following Baha surgery. The commonest complications are local infection and inflammation at the implant site. None of our patient had history of intraoperative or peri-operative complication following Baha implant surgery.

  13. Computer-based laparoscopic and robotic surgical simulators: performance characteristics and perceptions of new users. (United States)

    Lin, David W; Romanelli, John R; Kuhn, Jay N; Thompson, Renee E; Bush, Ron W; Seymour, Neal E


    This study aimed to define perceptions of the need and the value of new simulation devices for laparoscopic and robot-assisted surgery. The initial experience of surgeons using both robotic and nonrobotic laparoscopic simulators to perform an advanced laparoscopic skill was evaluated. At the 2006 Society of American Gastroesophageal Surgeons (SAGES) meeting, 63 Learning Center attendees used a new virtual reality robotic surgery simulator (SEP Robot) and either a computer-enhanced laparoscopic simulator (ProMIS) or a virtual reality simulator (SurgicalSIM). Demographic and training data were collected by an intake survey. Subjects then were assessed during one iteration of laparoscopic suturing and knot-tying on the SEP Robot and either the ProMIS or the SurgicalSIM. A posttask survey determined users' impressions of task realism, interface quality, and educational value. Performance data were collected and comparisons made between user-defined groups, different simulation platforms, and posttask survey responses. The task completion rate was significantly greater for experts than for nonexperts on the virtual reality platforms (SurgicalSIM: 100% vs 36%; SEP Robot: 93% vs 63%; p platforms, whereas simulator metrics best discriminated expertise for the videoscopic platform. Similar comparisons for the virtual reality platforms were not feasible because of the low task completion rate for nonexperts. The added degrees of freedom associated with the robotic surgical simulator instruments facilitated completion of the task by nonexperts. All platforms were perceived as effective training tools.

  14. Surgical construction of a novel simulated carotid siphon in canines

    International Nuclear Information System (INIS)

    Tan Huaqiao; Li Minghua; Zhu Yueqi; Fang Chun; Wang Jue; Wu Chungen; Cheng Yingsheng; Xie Jian; Zhang He


    Objective: To develop in vivo carotid siphon models by surgical method using the shaped devices for testing the performance of covered stent specially designed for intracranial vascular diseases. Methods: Six carotid siphon-shaped devices were established using stereolithographic biomodeling and the lost-wax technique. Six canines underwent surgery to expose and isolate bilateral CCA. The right CCA origin was ligated and incised distal to the ligation point after the distal right CCA was temporarily closed. The distal left CCA was ligated and incised proximal to the ligation point after the left CCA origin was closed. The proximal isolated left CCA was passed through the shaped device. The distal isolated right CCA and the proximal isolated left CCA were anastomosed end-to-end. Finally, the shaped device of carotid siphon was fixed with suture and embedded in the left neck. The intraarterial DSA was performed on postprocedural 7 days, 2 weeks and 1 month. The morphological characteristics of carotid siphon models were visually evaluated by two observers. The patency of siphon model and the stenosis of anastomotic stoma were followed-up. Results: All animals tolerated the surgical procedure well with mean model time construction of 90 minutes. The morphological characteristics of siphon models were similar to those in human. The anastomotic stoma stenosis occurred in 2 siphon models, and thrombosis of anastomotic stoma in 1, but all siphons of these models were patent on post-procedural follow-up angiography. Conclusion: Surgical construction of an in vivo carotid siphon model of canine with shaped device is practically feasible. This model can be used for testing neurovascular devices. (authors)

  15. Best practices across surgical specialties relating to simulation-based training. (United States)

    Gardner, Aimee K; Scott, Daniel J; Pedowitz, Robert A; Sweet, Robert M; Feins, Richard H; Deutsch, Ellen S; Sachdeva, Ajit K


    Simulation-based training is playing an increasingly important role in surgery. However, there is insufficient discussion among the surgical specialties regarding how simulation may best be leveraged for training. There is much to be learned from one another as we all strive to meet new requirements within the context of Undergraduate Medical Education, Graduate Medical Education, and Continuing Medical Education. To address this need, a panel was convened at the 6th Annual Meeting of the Consortium of the American College of Surgeons-Accredited Education Institutes consisting of key leaders in the field of simulation from 4 surgical subspecialties, namely, general surgery, orthopedic surgery, cardiothoracic surgery, urology, and otolaryngology. An overview of how the 5 surgical specialties are using simulation-based training to meet a wide array of educational needs for all levels of learners is presented. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Design, development and clinical validation of computer-aided surgical simulation system for streamlined orthognathic surgical planning. (United States)

    Yuan, Peng; Mai, Huaming; Li, Jianfu; Ho, Dennis Chun-Yu; Lai, Yingying; Liu, Siting; Kim, Daeseung; Xiong, Zixiang; Alfi, David M; Teichgraeber, John F; Gateno, Jaime; Xia, James J


    There are many proven problems associated with traditional surgical planning methods for orthognathic surgery. To address these problems, we developed a computer-aided surgical simulation (CASS) system, the AnatomicAligner, to plan orthognathic surgery following our streamlined clinical protocol. The system includes six modules: image segmentation and three-dimensional (3D) reconstruction, registration and reorientation of models to neutral head posture, 3D cephalometric analysis, virtual osteotomy, surgical simulation, and surgical splint generation. The accuracy of the system was validated in a stepwise fashion: first to evaluate the accuracy of AnatomicAligner using 30 sets of patient data, then to evaluate the fitting of splints generated by AnatomicAligner using 10 sets of patient data. The industrial gold standard system, Mimics, was used as the reference. When comparing the results of segmentation, virtual osteotomy and transformation achieved with AnatomicAligner to the ones achieved with Mimics, the absolute deviation between the two systems was clinically insignificant. The average surface deviation between the two models after 3D model reconstruction in AnatomicAligner and Mimics was 0.3 mm with a standard deviation (SD) of 0.03 mm. All the average surface deviations between the two models after virtual osteotomy and transformations were smaller than 0.01 mm with a SD of 0.01 mm. In addition, the fitting of splints generated by AnatomicAligner was at least as good as the ones generated by Mimics. We successfully developed a CASS system, the AnatomicAligner, for planning orthognathic surgery following the streamlined planning protocol. The system has been proven accurate. AnatomicAligner will soon be available freely to the boarder clinical and research communities.

  17. Virtual reality simulators: valuable surgical skills trainers or video games? (United States)

    Willis, Ross E; Gomez, Pedro Pablo; Ivatury, Srinivas J; Mitra, Hari S; Van Sickle, Kent R


    Virtual reality (VR) and physical model (PM) simulators differ in terms of whether the trainee is manipulating actual 3-dimensional objects (PM) or computer-generated 3-dimensional objects (VR). Much like video games (VG), VR simulators utilize computer-generated graphics. These differences may have profound effects on the utility of VR and PM training platforms. In this study, we aimed to determine whether a relationship exists between VR, PM, and VG platforms. VR and PM simulators for laparoscopic camera navigation ([LCN], experiment 1) and flexible endoscopy ([FE] experiment 2) were used in this study. In experiment 1, 20 laparoscopic novices played VG and performed 0° and 30° LCN exercises on VR and PM simulators. In experiment 2, 20 FE novices played VG and performed colonoscopy exercises on VR and PM simulators. In both experiments, VG performance was correlated with VR performance but not with PM performance. Performance on VR simulators did not correlate with performance on respective PM models. VR environments may be more like VG than previously thought. © 2013 Published by Association of Program Directors in Surgery on behalf of Association of Program Directors in Surgery.

  18. Sleep deprivation increases cognitive workload during simulated surgical tasks. (United States)

    Tomasko, Jonathan M; Pauli, Eric M; Kunselman, Allen R; Haluck, Randy S


    There have been conflicting reports of the effects of modest sleep deprivation on surgical skills. The aim of this study was to assess the effects of a 24-hour call shift on technical and cognitive function, as well as the ability to learning a new skill. Thirty-one students trained to expert proficiency on a virtual reality part-task trainer. They then were randomized to either a control or sleep-deprived group. On the second testing day they were given a novel task. Fatigue was assessed using the Epworth Sleepiness Scale. The National Aeronautics and Space Administration-Task Load Index was used to assess cognitive capabilities. There was no difference between the control and sleep-deprived groups for performance or learning of surgical tasks. Subjectively, the Epworth Sleepiness Scale showed an increase in sleepiness. The National Aeronautics and Space Administration-Task Load Index showed an increase in total subjective mental workload for the sleep-deprived group. Sleep-deprived subjects were able to complete the tasks despite the increased workload, and were able to learn a new task proficiently, despite an increase in sleepiness. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Simulation based education - models for teaching surgical skills in general practice. (United States)

    Sinha, Sankar; Cooling, Nicholas


    Simulation based education is an accepted method of teaching procedural skills in both undergraduate and postgraduate medical education. There is an increasing need for developing authentic simulation models for use in general practice training. This article describes the preparation of three simulation models to teach general practice registrars basic surgical skills, including excision of a sebaceous cyst and debridement and escharectomy of chronic wounds. The role of deliberate practise in improving performance of procedural skills with simulation based education is well established. The simulation models described are inexpensive, authentic and can be easily prepared. They have been used in general practice education programs with positive feedback from participants and could potentially be used as in-practice teaching tools by general practitioner supervisors. Importantly, no simulation can exactly replicate the actual clinical situation, especially when complications arise. It is important that registrars are provided with adequate supervision when initially applying these surgical skills to patients.

  20. Prospective Analysis of Surgical Bone Margins After Partial Foot Amputation in Diabetic Patients Admitted With Moderate to Severe Foot Infections. (United States)

    Schmidt, Brian M; McHugh, Jonathan B; Patel, Rajiv M; Wrobel, James S


    Osteomyelitis is common in diabetic foot infections and medical management can lead to poor outcomes. Surgical management involves sending histopathologic and microbiologic specimens which guides future intervention. We examined the effect of obtainment of surgical margins in patients undergoing forefoot amputations to identify patient characteristics associated with outcomes. Secondary aims included evaluating interobserver reliability of histopathologic data at both the distal-to and proximal-to surgical bone margin. Data were prospectively collected on 72 individuals and was pooled for analysis. Standardized method to retrieve intraoperative bone margins was established. A univariate analysis was performed. Negative outcomes, including major lower extremity amputation, wound dehiscence, reulceration, reamputation, or death were recorded. Viable proximal margins were obtained in 63 out of 72 cases (87.5%). Strong interobserver reliability of histopathology was recorded. Univariate analysis demonstrated preoperative platelets, albumin, probe-to-bone testing, absolute toe pressures, smaller wound surface area were associated with obtaining viable margins. Residual osteomyelitis resulted in readmission 2.6 times more often and more postoperative complications. Certain patients were significantly different in the viable margin group versus dirty margin group. High interobserver reliability was demonstrated. Obtainment of viable margins resulted in reduced rates of readmission and negative outcomes. Prognostic, Level I: Prospective.

  1. Learning style and laparoscopic experience in psychomotor skill performance using a virtual reality surgical simulator. (United States)

    Windsor, John A; Diener, Scott; Zoha, Farah


    People learn in different ways, and training techniques and technologies should accommodate individual learning needs. This pilot study looks at the relationship between learning style, as measured with the Multiple Intelligences Developmental Assessment Scales (MIDAS), laparoscopic surgery experience and psychomotor skill performance using the MIST VR surgical simulator. Five groups of volunteer subjects were selected from undergraduate tertiary students, medical students, novice surgical trainees, advanced surgical trainees and experienced laparoscopic surgeons. Each group was administered the MIDAS followed by two simulated surgical tasks on the MIST VR simulator. There was a striking homogeny of learning styles amongst experienced laparoscopic surgeons. Significant differences in the distribution of primary learning styles were found (P < .01) between subjects with minimal surgical training and those with considerable experience. A bodily-kinesthetic learning style, irrespective of experience, was associated with the best performance of the laparoscopic tasks. This is the first study to highlight the relationship between learning style, psychomotor skill and laparoscopic surgical experience with implications for surgeon selection, training and credentialling.

  2. Use of a patient-specific CAD/CAM surgical jig in extremity bone tumor resection and custom prosthetic reconstruction. (United States)

    Wong, K C; Kumta, S M; Sze, K Y; Wong, C M


    Computer navigation has recently been introduced for bone tumor surgery in the orthopedic field, with the aim of achieving increased accuracy and precision in tumor resection and in custom prosthetic reconstruction. However, the technique requires bulky navigation facilities, the presence of a system operator in the operating room, and surgeons with prior experience in navigated surgery. We describe a new and simple method of using a patient-specific computer-aided design/computer-aided modeling (CAD/CAM) surgical jig to realize the preoperative planning in the surgical field. The accuracy of the proposed method was first tested in a cadaver trial. It took one minute to set the location of the jig prior to the bone resection and three minutes to perform the bone resections via the cutting slits of the jig. The dimensional difference between the achieved and planned bone resection was jig, and a custom CAD prosthesis reconstruction matched accurately to the skeletal defect. Further assessment in a larger population is necessary to determine the clinical efficacy of the technique.

  3. Densitometry test of bone tissue: valiadation of computer simulation studies

    NARCIS (Netherlands)

    Binkowski, M.; Tanck, E.; Barink, M.; Oyen, W.J.; Wrobel, Z.; Verdonschot, Nicolaas Jacobus Joseph


    Bone densitometry measurements are performed to predict the fracture risk in bones. However, the sensitivity of these predictions are not satisfactory. One of the explanations is that densitometry ignores the (architectural) structural aspects of the bone. The effects of varying architectural

  4. Densitometry test of bone tissue: validation of computer simulation studies.

    NARCIS (Netherlands)

    Binkowski, M.; Tanck, E.; Barink, M.; Oyen, W.J.G.; Wrobel, Z.; Verdonschot, N.J.J.


    Bone densitometry measurements are performed to predict the fracture risk in bones. However, the sensitivity of these predictions are not satisfactory. One of the explanations is that densitometry ignores the (architectural) structural aspects of the bone. The effects of varying architectural

  5. Importance of bone scintigraphy in children from a surgical and orthopedic point of view

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, A.D.; Carro, G.A.

    Sixty children with Legg-Perthes disease (19), bone tumor (27), osteogenesis imperfecta (7), osteomyelitis (5) and transient synovitis (2) were studied using sup(99m)Tc labeled diphosphonate. A number of benign or malign bone diseases of children need early detection in order to institute the best form - the fine form - of treatment. We recommend the bone scintigraphy in the initial screening of children with signs and symptoms of bone pathology.

  6. Pilot study on effectiveness of simulation for surgical robot design using manipulability. (United States)

    Kawamura, Kazuya; Seno, Hiroto; Kobayashi, Yo; Fujie, Masakatsu G


    Medical technology has advanced with the introduction of robot technology, which facilitates some traditional medical treatments that previously were very difficult. However, at present, surgical robots are used in limited medical domains because these robots are designed using only data obtained from adult patients and are not suitable for targets having different properties, such as children. Therefore, surgical robots are required to perform specific functions for each clinical case. In addition, the robots must exhibit sufficiently high movability and operability for each case. In the present study, we focused on evaluation of the mechanism and configuration of a surgical robot by a simulation based on movability and operability during an operation. We previously proposed the development of a simulator system that reproduces the conditions of a robot and a target in a virtual patient body to evaluate the operability of the surgeon during an operation. In the present paper, we describe a simple experiment to verify the condition of the surgical assisting robot during an operation. In this experiment, the operation imitating suturing motion was carried out in a virtual workspace, and the surgical robot was evaluated based on manipulability as an indicator of movability. As the result, it was confirmed that the robot was controlled with low manipulability of the left side manipulator during the suturing. This simulation system can verify the less movable condition of a robot before developing an actual robot. Our results show the effectiveness of this proposed simulation system.

  7. The use of virtual reality simulation of head trauma in a surgical boot camp. (United States)

    Vergara, Victor M; Panaiotis; Kingsley, Darra; Alverson, Dale C; Godsmith, Timothy; Xia, Shan; Caudell, Thomas P


    Surgical "boot camps" provide excellent opportunities to enhance orientation, learning, and preparation of new surgery interns as they enter the clinical arena. This paper describes the utilization of an interactive virtual reality (VR) simulation and associated virtual patient (VP) as an additional tool for surgical boot camps. Complementing other forms of simulation, virtual patients (VPs) require less specialized equipment and can also provide a wide variety of medical scenarios. In this paper we discuss a study that measured the learning effectiveness of a real-world VP simulation used by a class of new surgery interns who operated it with a standard computer interface. The usability of the simulator as a learning tool has been demonstrated and measured. This study brings the use of VR simulation with VPs closer to wider application and integration into a training curriculum, such as a surgery intern boot camp.

  8. Surgical simulation: where have we come from? Where are we now? Where are we going? (United States)

    Munro, Malcolm G


    It is now clear to most stakeholders that acquisition of surgical psychomotor skills is best achieved outside of the clinical operating room, in the context of a simulated environment. Endoscopic simulation can be accomplished using simple "box" simulators or video trainers, and virtual reality simulation is now possible using microprocessor-controlled systems. Structured surgical training performed outside of the operating room environment is relatively new to health care, a circumstance different from the process of pilot training, in which simulation has been a mainstay for more than 75 years and in which virtual reality simulation is now the norm. Those charged with surgical education are faced with a dilemma as, while attempting to understand the basic goals of simulation, they are simultaneously faced with choice between relatively inexpensive video trainers and the often prohibitively expensive virtual reality systems. This article explores the history of simulation, reports the results of a modified systematic review of currently available systems and performance, and identifies the gaps in current research and development. It is apparent that available video trainers provide the opportunity for skill development that at present is not surpassed by virtual reality systems. In the future, there will likely be an increasing role for virtual reality; however, challenges remain that include determination of the appropriate metrics and system design, and the fiscal resources necessary for the required hardware and related software development. Copyright © 2012 AAGL. Published by Elsevier Inc. All rights reserved.

  9. Bone mineral content reduction in youth with surgical form of Schistosomiasis mansoni: factors involved in the pathogenesis

    Directory of Open Access Journals (Sweden)

    Brandt Carlos Teixeira


    Full Text Available Thirty two children and adolescents from 14 to 20 years of age, suffering from hepatosplenic schistosomiasis mansoni and bleeding esophageal varicose veins, were evaluated for bone mineral density (BMD, before undergoing medical and surgical treatment. The surgical protocol was splenectomy, autoimplantation of spleen tissue into a pouch of the major omentum and ligature of the left gastric vein. Follow up of these patients? ranges from one to ten years with a mean of five years. The BMD was measured at the lumbar spine (L2 - L4 through the dual energy absorptionmetry X-ray (DEXA, using a LUNAR DPX-L densitometer. The degree of Symmers´ fibrosis was assessed by semiautomatic hystomorphometry. In eleven patients, the serum magnesium was measured before an intravenous overload of this ion and subsequently after eight and twenty four hours. Urine was collected 24 hours before and 24 hours after the magnesium overload. Deficiency of magnesium was considered when the uptake of this ion was greater than 40%. There was a significant trend of association between the status of bone mineral content and the Symmers´ fibrosis degree (c² = 6.606 R = 0.01017. There was also a moderate agreement between the greater fibrosis densities ( > the mean percentage and bone mineral deficits. Although the normal bone mineral content was more found among the patients with better hepatic functional reserve, the results did not reach statistical significance. There was a marked magnesium retention (>95% in one patient who had severe osteoporosis and a slight depletion (<5% in another patient, who presented no bone mineral deficit. It was concluded that the patients included in this series, showed an important BMD deficit, specially among the females which has had a significant improvement after medical and surgical treatment. Bone mineral deficit was associated with the degree of Symmers´ fibrosis. Magnesium depletion was present in two out of eleven patients. It is

  10. Efficacy of platelet rich plasma and hydroxyapatite crystals in bone regeneration after surgical removal of mandibular third molars. (United States)

    Kaur, Preeti; Maria, Anisha


    This study evaluates the efficacy of platelet rich plasma (PRP) & porous hydroxyapatite crystals in bone regeneration after surgical removal of mandibular third molar with the help of radiographs and its comparison with control side. A total of 40 patients; both male and female aged between 18 and 35 years, who had impacted mandibular third molars were randomly selected for this study. Twenty patients were taken for control group and 20 patients for study group. The extraction socket of the study group was packed with PRP and hydroxyapatite granules and that of control group was sutured without PRP and hydroxyapatite. The bone density of both extraction sockets were evaluated radiographically using gray level histogram and compared periodically on immediate postoperative day, 1st and 3rd month postoperatively and postoperative sequelae of both the control group and study group in terms of oedema & pain or any other adverse reactions were also assessed. Data suggested evidence of early bone formation and maturation radiographically in study group as compared to control group. The percentage of facial swelling was numerically greater on the control side as compared to the study side, Pain was also assessed with VAS and it was found that the severity of pain was equal in both study and control groups and the results were not significant. This study clearly indicated a definitive improvement in the wound healing, increase in bone density, which signifies and highlights the use of PRP and hydroxyapatite granules, certainly as a valid method in inducing and accelerating bone regeneration.

  11. Evaluation of dynamic [18F]-FDG-PET imaging for the detection of acute post-surgical bone infection.

    Directory of Open Access Journals (Sweden)

    Tracy L Y Brown

    Full Text Available Diagnosing bone infection in its acute early stage is of utmost clinical importance as the failure to do so results in a therapeutically recalcitrant chronic infection that can only be resolved with extensive surgical intervention, the end result often being a structurally unstable defect requiring reconstructive procedures. [(18F]-FDG-PET has been extensively investigated for this purpose, but the results have been mixed in that, while highly sensitive, its specificity with respect to distinguishing between acute infection and sterile inflammatory processes, including normal recuperative post-surgical healing, is limited. This study investigated the possibility that alternative means of acquiring and analyzing FDG-PET data could be used to overcome this lack of specificity without an unacceptable loss of sensitivity. This was done in the context of an experimental rabbit model of post-surgical osteomyelitis with the objective of distinguishing between acute infection and sterile post-surgical inflammation. Imaging was done 7 and 14 days after surgery with continuous data acquisition for a 90-minute period after administration of tracer. Results were evaluated based on both single and dual time point data analysis. The results suggest that the diagnostic utility of FDG-PET is likely limited to well-defined clinical circumstances. We conclude that, in the complicated clinical context of acute post-surgical or post-traumatic infection, the diagnostic utility accuracy of FDG-PET is severely limited based on its focus on the increased glucose utilization that is generally characteristic of inflammatory processes.

  12. Virtual reality surgical simulation for lower urinary tract endoscopy and procedures. (United States)

    Manyak, Michael J; Santangelo, Kristin; Hahn, James; Kaufman, Roger; Carleton, Thurston; Hua, Xing Cheng; Walsh, Raymond J


    To provide a realistic experience of lower urinary tract endoscopic procedures, we have developed and continue to expand a computer-based surgical simulator that incorporates a surgical tool interface with anatomic detail and haptic feedback. Surface-based geometric data for the lower urinary tract were generated from the National Library of Medicine Visible Human dataset. The three-dimensional texture map of the surface geometry was developed from recorded endoscopic video procedures. Geometry and associated texture maps were rendered in real time using the Silicon Graphics Extreme Impacts program. The surgical interface device incorporated all normal ranges of motion and resistance that occur within an actual operative environment. The hands-on endoscopic device attached to the interface device was provided by Circon-ACMI, Inc. Urologic residents evaluated the program for correlation with actual endoscopic procedures. Texture-mapped digitized images provided a close anatomic similarity to actual videoendoscopic images. Virtual endoscopy of the lower urinary tract was reproducible and closely simulated actual visual and tactile endoscopic experience. Virtual reality surgical simulation is feasible for a variety of lower urinary tract procedures. This system coordinates visual perception with appropriate haptic feedback in both longitudinal and rotational axes. These types of procedures may be incorporated into future educational experiences for urologists to introduce new techniques and to provide documentation of surgical experience.

  13. A model for predicting the GEARS score from virtual reality surgical simulator metrics. (United States)

    Dubin, Ariel Kate; Julian, Danielle; Tanaka, Alyssa; Mattingly, Patricia; Smith, Roger


    Surgical education relies heavily upon simulation. Assessment tools include robotic simulator assessments and Global Evaluative Assessment of Robotic Skills (GEARS) metrics, which have been validated. Training programs use GEARS for proficiency testing; however, it requires a trained human evaluator. Due to limited time, learners are reliant on surgical simulator feedback to improve their skills. GEARS and simulator scores have been shown to be correlated but in what capacity is unknown. Our goal is to develop a model for predicting GEARS score using simulator metrics. Linear and multivariate logistic regressions were used on previously reported data by this group. Subjects performed simple (Ring and Rail 1) and complex (Suture Sponge 1) tasks on simulators, the dV-Trainer (dVT) and the da Vinci Skills Simulator (dVSS). They were scored via simulator metrics and GEARS. A linear model for each simulator and exercise showed a positive linear correlation. Equations were developed for predicting GEARS Total Score from simulator Overall Score. Next, the effects of each individual simulator metric on the GEARS Total Score for each simulator and exercise were examined. On the dVSS, Excessive Instrument Force was significant for Ring and Rail 1 and Instrument Collision was significant for Suture Sponge 1. On the dVT, Time to Complete was significant for both exercises. Once the significant variables were identified, multivariate models were generated. Comparing the predicted GEARS Total Score from the linear model (using only simulator Overall Score) to that using the multivariate model (using the significant variables for each simulator and exercise), the results were similar. Our results suggest that trainees can use simulator Overall Score to predict GEARS Total Score using our linear regression equations. This can improve the training process for those preparing for high-stakes assessments.

  14. Comparative analysis of the functionality of simulators of the da Vinci surgical robot. (United States)

    Smith, Roger; Truong, Mireille; Perez, Manuela


    The implementation of robotic technology in minimally invasive surgery has led to the need to develop more efficient and effective training methods, as well as assessment and skill maintenance tools for surgical education. Multiple simulators and procedures are available for educational and training purposes. A need for comparative evaluations of these simulators exists to aid users in selecting an appropriate device for their purposes. We conducted an objective review and comparison of the design and capabilities of all dedicated simulators of the da Vinci robot, the da Vinci Skill Simulator (DVSS) (Intuitive Surgical Inc., Sunnyvale, CA, USA), dV-Trainer (dVT) (Mimic Technologies Inc., Seattle, WA, USA), and Robotic Surgery Simulator (RoSS) (Simulated Surgical Skills, LLC, Williamsville, NY, USA). This provides base specifications of the hardware and software, with an emphasis on the training capabilities of each system. Each simulator contains a large number of training exercises, DVSS = 40, dVT = 65, and RoSS = 52 for skills development. All three offer 3D visual images but use different display technologies. The DVSS leverages the real robotic surgeon's console to provide visualization, hand controls, and foot pedals. The dVT and RoSS created simulated versions of all of these control systems. They include systems management services which allow instructors to collect, export, and analyze the scores of students using the simulators. This study is the first to provide comparative information of the three simulators functional capabilities with an emphasis on their educational skills. They offer unique advantages and capabilities in training robotic surgeons. Each device has been the subject of multiple validation experiments which have been published in the literature. But those do not provide specific details on the capabilities of the simulators which are necessary for an understanding sufficient to select the one best suited for an organization's needs.

  15. Step-based cognitive virtual surgery simulation: an innovative approach to surgical education. (United States)

    Oliker, Aaron; Napier, Zachary; Deluccia, Nicolette; Qualter, John; Sculli, Frank; Smith, Brandon; Stern, Carrie; Flores, Roberto; Hazen, Alexes; McCarthy, Joseph


    BioDigital Systems, LLC in collaboration with New York University Langone Medical Center Department of Reconstructive Plastic Surgery has created a complex, real-time, step-based simulation platform for plastic surgery education. These simulators combine live surgical footage, interactive 3D visualization, text labels, and voiceover as well as a high-yield, expert-approved testing mode to create a comprehensive virtual educational environment for the plastic surgery resident or physician.

  16. The place of simulation in the surgical resident curriculum. The pedagogic program of the Nice Medical School Simulation Center. (United States)

    Bréaud, J; Chevallier, D; Benizri, E; Fournier, J-P; Carles, M; Delotte, J; Venissac, N; Myx, A; Ianelli, A; Levraut, J; Jones, D; Benchimol, D


    Surgical training relies on medical school lectures, practical training in patient care and in the operating room including instruction in anatomy and experimental surgery. Training with different techniques of simulators can complete this. Simulator-based training, widely used in North America, can be applied to several aspects of surgical training without any risk for patients: technical skills in both open and laparoscopic surgery, the notion of teamwork and the multidisciplinary management of acute medicosurgical situations. We present the curriculum developed in the Simulation Center of the Medical School of Nice Sophia-Antipolis. All residents in training at the Medical School participate in this curriculum. Each medical student is required to pursue theoretical training (familiarization with the operating room check-list), training in patient management using a high fidelity mannequin for various medical and surgical scenarios and training in technical gestures in open and laparoscopic surgery over a 2-year period, followed by an examination to validate all technical aptitudes. This curriculum has been approved and accredited by the prestigious American College of Surgeons, making this the first of its kind in France. As such, it should be considered as a model and, in accordance to the wishes of the French Surgical Academy, the first step toward the creation of true schools of surgery. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  17. Surgical and nonsurgical management of sagittal slab fractures of the third carpal bone in racehorses: 32 cases (1991-2001). (United States)

    Kraus, Beth M; Ross, Michael W; Boston, Raymond C


    To compare results (ie, return to racing and earnings per race start) of surgical versus nonsurgical management of sagittal slab fractures of the third carpal bone in racehorses. Retrospective study. 32 racehorses (19 Thoroughbreds, 11 Standardbreds, and 2 Arabians). Medical records and radiographs were reviewed to obtain information regarding signalment and treatment. Follow-up information was obtained from race records. Robust regression analysis was performed to evaluate earnings per start in horses that raced at least once before and after injury. 22 (69%) horses raced at least once after treatment of the fracture. All 7 horses treated by means of interfragmentary compression raced after treatment, and horses that underwent interfragmentary compression had significantly higher earnings per start after the injury than did horses treated without surgery. Eight of 9 horses treated by means of arthroscopic debridement of the damaged cartilage and bone raced after treatment, but only 7 of 16 horses treated without surgery (ie, stall rest) were able to return to racing after treatment. Results suggest that racehorses with sagittal slab fractures of the third carpal bone have a favorable prognosis for return to racing after treatment. Horses treated surgically were more likely to race after treatment than were horses treated without surgery.

  18. Surgical therapy of primary malignant bone tumours and soft tissue sarcomas of the chest wall: a two-institutional experience. (United States)

    Friesenbichler, Joerg; Leithner, Andreas; Maurer-Ertl, Werner; Szkandera, Joanna; Sadoghi, Patrick; Frings, Andreas; Maier, Alfred; Andreou, Dimosthenis; Windhager, Reinhard; Tunn, Per-Ulf


    Primary malignant bone tumours and soft tissue sarcomas of the chest wall are exceedingly rare entities. The aim of this study was a retrospective two-institutional analysis of surgical therapy with respect to the kind and amount of the resection performed, the type of reconstruction and the oncological outcome. Between September 1999 and August 2010 31 patients (seven women and 24 men) were treated due to a primary malignant bone tumour or soft tissue sarcoma of the chest wall in two centres. Eight low-grade sarcomas were noted as well as 23 highly malignant sarcomas. The tumours originated from the sternum in six cases, from the ribs in 12 cases, from the soft tissues of the thoracic wall in 11 cases and from a vertebral body and the clavicle in one case each. In 26 cases wide resection margins were achieved, while four were intralesional and one was marginal. In all 31 cases the defect of the chest wall was reconstructed using mesh grafts. At a mean follow-up of 51 months 20 patients were without evidence of disease, three were alive with disease, seven patients had died and one patient was lost to follow-up. One recurrence was detected after wide resection of a malignant triton tumour. Primary malignant bone tumour or soft tissue sarcoma of the chest wall should be treated according to the same surgical oncological principles as established for the extremities. Reconstruction with mesh grafts and musculocutaneous flaps is associated with a low morbidity.

  19. Guided bone regeneration following surgical treatment of a rare variant of Pindborg tumor: a case report. (United States)

    Mariano, Ronaldo C; Oliveira, Marina R; Silva, Amanda C; Ferreira, Delano H; Almeida, Oslei P


    Calcifying epithelial odontogenic tumor is a benign neoplasm, but its local destructive potential may lead to the formation of major bone defects. Microscopically, there are some histological variants. Among them, we highlight the clear cell variant due to its more aggressive behavior and a higher incidence of relapse. In this context, it is pertinent to describe the clear cell variant of calcifying epithelial odontogenic tumor. Despite the large bone defect formed in the posterior region of the mandible, conservative treatment associated with guided bone regeneration assured complete bone formation and the absence of recurrence in an 8-year follow-up period.

  20. The effectiveness of and satisfaction with high-fidelity simulation to teach cardiac surgical resuscitation skills to nurses. (United States)

    McRae, Marion E; Chan, Alice; Hulett, Renee; Lee, Ai Jin; Coleman, Bernice


    There are few reports of the effectiveness or satisfaction with simulation to learn cardiac surgical resuscitation skills. To test the effect of simulation on the self-confidence of nurses to perform cardiac surgical resuscitation simulation and nurses' satisfaction with the simulation experience. A convenience sample of sixty nurses rated their self-confidence to perform cardiac surgical resuscitation skills before and after two simulations. Simulation performance was assessed. Subjects completed the Satisfaction with Simulation Experience scale and demographics. Self-confidence scores to perform all cardiac surgical skills as measured by paired t-tests were significantly increased after the simulation (d=-0.50 to 1.78). Self-confidence and cardiac surgical work experience were not correlated with time to performance. Total satisfaction scores were high (mean 80.2, SD 1.06) indicating satisfaction with the simulation. There was no correlation of the satisfaction scores with cardiac surgical work experience (τ=-0.05, ns). Self-confidence scores to perform cardiac surgical resuscitation procedures were higher after the simulation. Nurses were highly satisfied with the simulation experience. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Quantitative mandibular and maxillary CT bone densitometry in surgical planning for osseointegrated dental implants

    International Nuclear Information System (INIS)

    Rothman, S.L.G.; Chafetz, N.; Schwarz, M.S.; Rhodes, M.L.


    Computed tomographic (CT) scanning of the jaw is important in the preoperative evaluation of osseointegrated dental implants. The degree of bone mineralization may have a bearing on the likelihood of successful implantation. A phantom for analysis was scanned prior to CT studies. Measurements were made in 20 patients. Bone density was sampled inferior to normal teeth and in comparable but edentulous regions, in an attempt to define the limits of normal ossification. A wide variation in bone mineral was noted in normal teeth-bearing and in edentulous bone. Three patterns of ossification are identifiable with CT. Bone densitometry may indicate those patients for whom a longer recovery period between implantation and prosthetic placement is advised

  2. Surgical model-view-controller simulation software framework for local and collaborative applications. (United States)

    Maciel, Anderson; Sankaranarayanan, Ganesh; Halic, Tansel; Arikatla, Venkata Sreekanth; Lu, Zhonghua; De, Suvranu


    Surgical simulations require haptic interactions and collaboration in a shared virtual environment. A software framework for decoupled surgical simulation based on a multi-controller and multi-viewer model-view-controller (MVC) pattern was developed and tested. A software framework for multimodal virtual environments was designed, supporting both visual interactions and haptic feedback while providing developers with an integration tool for heterogeneous architectures maintaining high performance, simplicity of implementation, and straightforward extension. The framework uses decoupled simulation with updates of over 1,000 Hz for haptics and accommodates networked simulation with delays of over 1,000 ms without performance penalty. The simulation software framework was implemented and was used to support the design of virtual reality-based surgery simulation systems. The framework supports the high level of complexity of such applications and the fast response required for interaction with haptics. The efficacy of the framework was tested by implementation of a minimally invasive surgery simulator. A decoupled simulation approach can be implemented as a framework to handle simultaneous processes of the system at the various frame rates each process requires. The framework was successfully used to develop collaborative virtual environments (VEs) involving geographically distributed users connected through a network, with the results comparable to VEs for local users.

  3. Effect of biphasic calcium phosphate nanocomposite on healing of surgically created alveolar bone defects in beagle dogs (United States)

    Wang, Lanlei; Guan, Aizhong; Shi, Han; Chen, Yangxi; Liao, Yunmao


    The aim of the present study was to investigate the effect of porous biphasic calcium phosphate nanocomposite (nanoBCP) scaffolds bioceramic. Alveolar bone defects were surgically created bilaterally at the buccal aspects of the upper second premolar in fourteen beagle dogs. After root conditioning with ethylenediaminetetraacetate (EDTA), nanoBCP was randomly filled in the defects and nothing was put into the contralaterals as controls. Dogs were killed at the 12th weeks. Histological observations were processed through a light microscopy. The results revealed that a great amount of functional periodontal fissures formed in the defects in the nanoBCP groups while minimal bone took shape in the controls. In this study, nanoBCP has proved to work well as a biocompatible and osteoconductive scaffold material to promote periodontal regeneration effectively.

  4. Load-adaptive bone remodeling simulations reveal osteoporotic microstructural and mechanical changes in whole human vertebrae. (United States)

    Badilatti, Sandro D; Christen, Patrik; Parkinson, Ian; Müller, Ralph


    Osteoporosis is a major medical burden and its impact is expected to increase in our aging society. It is associated with low bone density and microstructural deterioration. Treatments are available, but the critical factor is to define individuals at risk from osteoporotic fractures. Computational simulations investigating not only changes in net bone tissue volume, but also changes in its microstructure where osteoporotic deterioration occur might help to better predict the risk of fractures. In this study, bone remodeling simulations with a mechanical feedback loop were used to predict microstructural changes due to osteoporosis and their impact on bone fragility from 50 to 80 years of age. Starting from homeostatic bone remodeling of a group of seven, mixed sex whole vertebrae, five mechanostat models mimicking different biological alterations associated with osteoporosis were developed, leading to imbalanced bone formation and resorption with a total net loss of bone tissue. A model with reduced bone formation rate and cell sensitivity led to the best match of morphometric indices compared to literature data and was chosen to predict postmenopausal osteoporotic bone loss in the whole group. Thirty years of osteoporotic bone loss were predicted with changes in morphometric indices in agreement with experimental measurements, and only showing major deviations in trabecular number and trabecular separation. In particular, although being optimized to match to the morphometric indices alone, the predicted bone loss revealed realistic changes on the organ level and on biomechanical competence. While the osteoporotic bone was able to maintain the mechanical stability to a great extent, higher fragility towards error loads was found for the osteoporotic bones. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Systematic review of skills transfer after surgical simulation-based training. (United States)

    Dawe, S R; Pena, G N; Windsor, J A; Broeders, J A J L; Cregan, P C; Hewett, P J; Maddern, G J


    Simulation-based training assumes that skills are directly transferable to the patient-based setting, but few studies have correlated simulated performance with surgical performance. A systematic search strategy was undertaken to find studies published since the last systematic review, published in 2007. Inclusion of articles was determined using a predetermined protocol, independent assessment by two reviewers and a final consensus decision. Studies that reported on the use of surgical simulation-based training and assessed the transferability of the acquired skills to a patient-based setting were included. Twenty-seven randomized clinical trials and seven non-randomized comparative studies were included. Fourteen studies investigated laparoscopic procedures, 13 endoscopic procedures and seven other procedures. These studies provided strong evidence that participants who reached proficiency in simulation-based training performed better in the patient-based setting than their counterparts who did not have simulation-based training. Simulation-based training was equally as effective as patient-based training for colonoscopy, laparoscopic camera navigation and endoscopic sinus surgery in the patient-based setting. These studies strengthen the evidence that simulation-based training, as part of a structured programme and incorporating predetermined proficiency levels, results in skills transfer to the operative setting. © 2014 BJS Society Ltd. Published by John Wiley & Sons Ltd.

  6. Age and gender effects on bone mass density variation: finite elements simulation. (United States)

    Barkaoui, Abdelwahed; Ben Kahla, Rabeb; Merzouki, Tarek; Hambli, Ridha


    Bone remodeling is a physiological process by which bone constantly adapts its structure to changes in long-term loading manifested by interactions between osteoclasts and osteoblasts. This process can be influenced by many local factors, via effects on bone cells differentiation and proliferation, which are produced by bone cells and act in a paracrine or autocrine way. The aim of the current work is to provide mechanobiological finite elements modeling coupling both cellular activities and mechanical behavior in order to investigate age and gender effects on bone remodeling evolution. A series of computational simulations have been performed on a 2D and 3D human proximal femur. An age- and gender-related impacts on bulk density alteration of trabecular bone have been noticed, and the major actors responsible of this phenomenon have been then discussed.

  7. Tele-surgical simulation system for training in the use of da Vinci surgery. (United States)

    Suzuki, Shigeyuki; Suzuki, Naoki; Hayashibe, Mitsuhiro; Hattori, Asaki; Konishi, Kozo; Kakeji, Yoshihiro; Hashizume, Makoto


    Laparoscopic surgery including robotic surgery allows the surgeon to be able to conduct minimally invasive surgery. A surgeon is required to master difficult skills for this surgery to compensate for the narrow field of view, limitation of work space, and the lack of depth sensation. To counteract these drawbacks, we have been developing a training simulation system that can allow surgeons to practice and master surgical procedures. In addition, our system aims to distribute a simulation program, to provide a means of collaboration between remote hospitals, and to be able to provide a means for guidance from an expert surgeon. In this paper, we would like to show the surgery simulation for da Vinci surgery, in particular a cholecystectomy. The integral parts of this system are a soft tissue model which is created by the sphere-filled method enabling real-time deformations based on a patient's data, force feedback devices known as a PHANToM and the Internet connection. By using this system a surgeon can perform surgical maneuvers such as pushing, grasping, and detachment in real-time manipulation. Moreover, using the broadband communication, we can perform the tele-surgical simulation for training.

  8. Effect of sleep deprivation on the performance of simulated anterior segment surgical skill. (United States)

    Erie, Elizabeth A; Mahr, Michael A; Hodge, David O; Erie, Jay C


    To measure the effect, using a computer simulator, of acute sleep deprivation on the performance of simulated anterior segment surgery skill. Prospective, non-randomized interventional study. Nine ophthalmology residents (3 residents each from post-graduate years 2, 3, and 4). Nine ophthalmology residents were tested on the Eyesi surgical simulator on 3 occasions; pre-call or rested (≥ 7 hours of sleep in previous 24 hours), post-work (8 hour work day and ≥ 7 hours sleep in previous 24 hours), and post-call or sleep-deprived (sleep in previous 24 hours). Residents were tested using the Eyesi forceps module and antitremor module. Level of sleepiness was assessed using the Epworth Sleepiness Scale (ESS). Differences were compared using a 3-factor repeated-measure analysis of variance to account for multiple comparisons. Compared with pre-call and post-work, post-call residents had significantly less sleep in the previous 24 hours (p technical performance using the antitremor module in pre-call (85 ± 21 points), post-work (80 ± 24 points), and post-call (81 ± 27 points; p = 0.51) residents or using the forceps module in pre-call (99 ± 1 points), post-work (98 ± 4 points), and post-call (98 ± 5 points; p = 0.11) residents. Acute sleep deprivation had no detectable impact on the performance of selected surgical task outcome measures when tested using the Eyesi surgical simulator.

  9. Endoscopic simulator curriculum improves colonoscopy performance in novice surgical interns as demonstrated in a swine model. (United States)

    Telem, Dana A; Rattner, David W; Gee, Denise W


    The purpose of this study was to determine whether independent virtual endoscopic training accelerates the acquisition of endoscopic skill by novice surgical interns. Nine novice surgical interns participated in a prospective study comparing colonoscopy performance in a swine model before and after an independent simulator curriculum. An independent observer evaluated each intern for the ability to reach the cecum within 20 min and technical ability as determined by Global Assessment of Gastrointestinal Endoscopic Skills--Colonoscopy (GAGES-C) score and performance compared. In addition, at the conclusion of training, a post test of two basic simulated colonoscopy modules was completed and metrics evaluated. As a control, three attending physicians who routinely perform colonoscopy also completed colonoscopy in the swine model. Prior to endoscopic training, one (11 %) intern successfully intubated the cecum in 19.56 min. Following training, six (67 %) interns reached the cecum with mean time of 9.2 min (p curriculum intern times demonstrated the experts to be significantly faster (p curriculum demonstrated significantly improved GI Mentor™ performance in the efficiency (79 vs. 67.1 %, p = 0.05) and time to cecum (3.37 vs. 5.59 min, p = 0.01) metrics. No other significant difference was demonstrated in GAGES-C categories or other simulator parameter. Simulator training on the GI Mentor™ alone significantly improved endoscopic skills in novice surgical interns as demonstrated in a swine model. This study also identified parameters on the GI Mentor™ that could indicate 'clinical readiness'. This study supports the role for endoscopic simulator training in surgical resident education as an adjunct to clinical experience.

  10. The SEP "robot": a valid virtual reality robotic simulator for the Da Vinci Surgical System? (United States)

    van der Meijden, O A J; Broeders, I A M J; Schijven, M P


    The aim of the study was to determine if the concept of face and construct validity may apply to the SurgicalSim Educational Platform (SEP) "robot" simulator. The SEP robot simulator is a virtual reality (VR) simulator aiming to train users on the Da Vinci Surgical System. To determine the SEP's face validity, two questionnaires were constructed. First, a questionnaire was sent to users of the Da Vinci system (reference group) to determine a focused user-group opinion and their recommendations concerning VR-based training applications for robotic surgery. Next, clinical specialists were requested to complete a pre-tested face validity questionnaire after performing a suturing task on the SEP robot simulator. To determine the SEP's construct validity, outcome parameters of the suturing task were compared, for example, relative to participants' endoscopic experience. Correlations between endoscopic experience and outcome parameters of the performed suturing task were tested for significance. On an ordinal five-point, scale the average score for the quality of the simulator software was 3.4; for its hardware, 3.0. Over 80% agreed that it is important to train surgeons and surgical trainees to use the Da Vinci. There was a significant but marginal difference in tool tip trajectory (p = 0.050) and a nonsignificant difference in total procedure time (p = 0.138) in favor of the experienced group. In conclusion, the results of this study reflect a uniform positive opinion using VR training in robotic surgery. Concepts of face and construct validity of the SEP robotic simulator are present; however, these are not strong and need to be improved before implementation of the SEP robotic simulator in its present state for a validated training curriculum to be successful .

  11. Computer-assisted surgical planning and simulation for unilateral condylar benign lesions causing facial asymmetry. (United States)

    Lu, Chuan; He, Dongmei; Yang, Chi; Huang, Dong; Ellis, Edward


    The purpose of this study was to investigate the best surgical sequence for the treatment of unilateral condylar benign lesions causing facial asymmetry by applying computer-assisted surgical planning and simulation. Computed tomography (CT) data from 12 patients whose maxillary cant was corrected by maintaining the vertical position of the central incisors and equally intruding the long side of the maxilla and extruding the short side were analyzed by ProPlan CMF 1.4 software (Materialise Medical, Leuven, Belgium). Condylectomy and double jaw orthognathic surgery with 2 different surgical sequences were simulated: 1) maxillary LeFort I osteotomy first (MaxF), then condylectomy, followed by bilateral sagittal split ramus osteotomy (BSSO); and 2) mandible first (ManF), beginning with condylectomy, then BSSO, and lastly LeFort I osteotomy. The greatest space between the maxillary and mandibular first molar in the interim positions was measured virtually to compare the 2 surgical sequences. The vertical distance between the upper and lower teeth of ManF patients was significantly smaller than that of MaxF patients (mean 2.99 mm, P < .001). When occlusal cants are corrected by equally intruding one side and extruding the other side of the maxillary dentition, the interim position is more conducive to sequencing corrective surgery by performing condylectomy, then BSSO, followed by Le Fort I osteotomy. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Enhancing fundamental robot-assisted surgical proficiency by using a portable virtual simulator. (United States)

    Chien, Jung Hung; Suh, Irene H; Park, Shi-Hyun; Mukherjee, Mukul; Oleynikov, Dmitry; Siu, Ka-Chun


    The development of a virtual reality (VR) training platform provides an affordable interface. The learning effect of VR and the capability of skill transfer from the VR environment to clinical tasks require more investigation. Here, 14 medical students performed 2 fundamental surgical tasks-bimanual carrying (BC) and peg transfer (PT)-in actual and virtual environments. Participants in the VR group received VR training, whereas participants in the control group played a 3D game. The learning effect was examined by comparing kinematics between pretraining and posttraining in the da Vinci Surgical System. Differences between VR and playing the 3D game were also examined. Those who were trained with the VR simulator had significantly better performance in both actual PT (P = .002) and BC (P VR group compared with the 3D game group. However, playing the 3D game showed no significant enhancement of fundamental surgical skills in the actual PT task. The difference between pretraining and posttraining was significantly larger in the VR group than in the 3D game group in both the time to task completion (P = .002) and the total distance traveled (P = .027) for the actual PT task. Participants who played the 3D game seemed to perform even worse in posttraining. Training with the portable VR simulator improved robot-assisted surgical skill proficiency in comparison to playing a 3D game.

  13. Virtual vitreoretinal surgery: construction of a training programme on the Eyesi Surgical Simulator

    DEFF Research Database (Denmark)

    Vergmann, Anna Stage; Vestergaard, Anders Højslet; Grauslund, Jakob

    Purpose: The purpose of this study was to test the construct validity of a full virtual reality vitreoretinal training program at the Eyesi Surgical simulator. Design and methods: A virtual vitreoretinal training program was composed on the Eyesi Surgical simulator, software version 2.9.2 (VRmagic...... developed a training program in virtual vitreoretinal surgery with construct validity for four out of six modules and for overall score. This makes the program a useful tool in the training of future vitreoretinal surgeons....... GmbH, Manheim, Germany). It was completed twice by three groups: Group 1: Twenty medical students Group 2: Ten ophthalmology residents Group 3: Five vitreoretinal surgeons The program consisted of six training modules (Figure 1): Navigation level 2 (Nav2) Forceps Training level 5 (ForT5) Bimanual...

  14. An Evaluation of the Role of Simulation Training for Teaching Surgical Skills in Sub-Saharan Africa. (United States)

    Campain, Nicholas J; Kailavasan, Mithun; Chalwe, Mumba; Gobeze, Aberra A; Teferi, Getaneh; Lane, Robert; Biyani, Chandra Shekhar


    An estimated 5 billion people worldwide lack access to any surgical care, whilst surgical conditions account for 11-30% of the global burden of disease. Maximizing the effectiveness of surgical training is imperative to improve access to safe and essential surgical care on a global scale. Innovative methods of surgical training have been used in sub-Saharan Africa to attempt to improve the efficiency of training healthcare workers in surgery. Simulation training may have an important role in up-scaling and improving the efficiency of surgical training and has been widely used in SSA. Though not intended to be a systematic review, the role of simulation for teaching surgical skills in Sub-Saharan Africa was reviewed to assess the evidence for use and outcomes. A systematic search strategy was used to retrieve relevant studies from electronic databases PubMed, Ovid, Medline for pertinent articles published until August 2016. Studies that reported the use of simulation-based training for surgery in Africa were included. In all, 19 articles were included. A variety of innovative surgical training methods using simulation techniques were identified. Few studies reported any outcome data. Compared to the volume of surgical training initiatives that are known to take place in SSA, there is very limited good quality published evidence for the use of simulation training in this context. Simulation training presents an excellent modality to enhance and improve both volume and access to high quality surgical skills training, alongside other learning domains. There is a desperate need to meticulously evaluate the appropriateness and effectiveness of simulation training in SSA, where simulation training could have a large potential beneficial impact. Training programs should attempt to assess and report learner outcomes.

  15. Mini Surgical Simulation, Role Play, and Group and Behavioral Interviews in Resident Selection (United States)

    Ogunyemi, Dotun; Alexander, Carolyn; Tangchitnob, Edward; Kim, David Seil


    Background A robust selection process is critical to residents' “cultural fit” and success in their program. Traditional selection methods have shortcomings. Objective We describe a novel residency interview process for obstetrics-gynecology residents that incorporates behavioral, group, and surgical simulation multiple mini interviews (MMIs). Methods In 2010, the Cedars-Sinai Medical Center obstetrics-gynecology residency program developed surgical simulation, role play, ethics group interview, and Accreditation Council for Graduate Medical Education competency-based behavioral interview stations. Results From 2010 to 2012, a total of 199 applicants were interviewed, 62 ranked in the top 20, and 18 matched into the program. The MMI scores for interview stations were used in compiling our rank list and were found to adequately differentiate candidates. The MMI mean scores for role play, ethics interview, surgical simulation, and the behavioral interview for the top 20 ranked candidates were statistically significantly higher than those for other applicants. Standardized tests minimally correlated with various interview modalities. Applicants found the interview process acceptable. Implementing these MMI stations increased the total applicant interview time for the day by 15% (from 5.5 to 6.5 hours) and increased the face-to-face interview time from 2 to 4 hours. Approximately 42 hours of coordinator time was required for the yearly interview cycle. Conclusions A multifaceted interview process utilizing MMI, group interview, and surgical simulation MMI is feasible and acceptable. The approach may decrease subjectivity and reliance on traditional interview methods and facilitate the selection of “compatible” residents into the program. PMID:27413446

  16. Validation study of a computer-based open surgical trainer: SimPraxis(®) simulation platform. (United States)

    Tran, Linh N; Gupta, Priyanka; Poniatowski, Lauren H; Alanee, Shaheen; Dall'era, Marc A; Sweet, Robert M


    Technological advances have dramatically changed medical education, particularly in the era of work-hour restrictions, which increasingly highlights a need for novel methods to teach surgical skills. The purpose of this study was to evaluate the validity of a novel, computer-based, interactive, cognitive simulator for training surgeons to perform pelvic lymph node dissection (PLND). Eight prostate cancer experts evaluated the content of the simulator. Contextual aspects of the simulator were rated on a five-point Likert scale. The experts and nine first-year residents completed a simulated PLND. Time and deviations were logged, and the results were compared between experts and novices using the Mann-Whitney test. Before training, 88% of the experts felt that a validated simulator would be useful for PLND training. After testing, 100% of the experts felt that it would be more useful than standard video training. Eighty-eight percent stated that they would like to see the simulator in the curriculum of residency programs and 56% thought it would be useful for accreditation purposes. The experts felt that the simulator aided in overall understanding, training indications, concepts and steps of the procedure, training how to use an assistant, and enhanced the knowledge of anatomy. Median performance times taken by experts and interns to complete a PLND procedure on the simulator were 12.62 and 23.97 minutes, respectively. Median deviation from the incorporated procedure pathway for experts was 24.5 and was 89 for novices. We describe an interactive, computer-based simulator designed to assist in mastery of the cognitive steps of an open surgical procedure. This platform is intuitive and flexible, and could be applied to any stepwise medical procedure. Overall, experts outperformed novices in their performance on the trainer. Experts agreed that the content was acceptable, accurate, and representative.

  17. Validation study of a computer-based open surgical trainer: SimPraxis® simulation platform

    Directory of Open Access Journals (Sweden)

    Tran LN


    Full Text Available Linh N Tran,1 Priyanka Gupta,2 Lauren H Poniatowski,2 Shaheen Alanee,3 Marc A Dall’Era,4 Robert M Sweet21Department of Internal Medicine, Loma Linda University, Loma Linda, CA, 2Department of Urology, University of Minnesota, Minneapolis, MN, 3Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, 4Department of Urology, University of California, Davis, CA, USABackground: Technological advances have dramatically changed medical education, particularly in the era of work-hour restrictions, which increasingly highlights a need for novel methods to teach surgical skills. The purpose of this study was to evaluate the validity of a novel, computer-based, interactive, cognitive simulator for training surgeons to perform pelvic lymph node dissection (PLND.Methods: Eight prostate cancer experts evaluated the content of the simulator. Contextual aspects of the simulator were rated on a five-point Likert scale. The experts and nine first-year residents completed a simulated PLND. Time and deviations were logged, and the results were compared between experts and novices using the Mann–Whitney test.Results: Before training, 88% of the experts felt that a validated simulator would be useful for PLND training. After testing, 100% of the experts felt that it would be more useful than standard video training. Eighty-eight percent stated that they would like to see the simulator in the curriculum of residency programs and 56% thought it would be useful for accreditation purposes. The experts felt that the simulator aided in overall understanding, training indications, concepts and steps of the procedure, training how to use an assistant, and enhanced the knowledge of anatomy. Median performance times taken by experts and interns to complete a PLND procedure on the simulator were 12.62 and 23.97 minutes, respectively. Median deviation from the incorporated procedure pathway for experts was 24.5 and was 89 for novices

  18. Lessons from the surgical experience with simulators: incorporation into training and utilization in determining competency. (United States)

    Fried, Gerald M


    Simulation technology in laparoscopic surgery has developed in response to a need to teach fundamental surgical skills in a safe environment. The skill set needed was defined carefully according to the classic educational model of needs assessment. Once defined, the skills were modeled in a simulator. The recognition that a simulator need not have high fidelity to achieve significant educational value was important in keeping costs reasonably low. Intrinsic to an effective simulation program is a set of metrics or measurements of performance. These metrics provide motivation for the student and allow comparison among students. Once shown to be reliable and valid, the simulator metrics can be used to set reasonable goals and standards for certification. Although simulators permit verification of learning, point simulation testing cannot by itself be used at present to ensure competence. Until the predictive value of these tests has been validated further, competence still needs to be determined by expert assessment of observed performance in real cases and by measurable outcome variables from real procedures. Simulation training is most beneficial when incorporated into a curriculum that teaches the accompanying knowledge and judgment essential for safe practice of the skills taught in the simulator. The FLS program distributed by the Society of American Gastrointestinal and Endoscopic Surgeons and the American College of Surgeons is an example of a carefully planned and validated program that incorporates these principles in laparoscopic surgery education. The lessons learned from development of the FLS program can be useful in designing a similar program for flexible gastrointestinal endoscopy.

  19. Effect of sleep deprivation on the performance of simulated laparoscopic surgical skill. (United States)

    Eastridge, Brian J; Hamilton, Elizabeth C; O'Keefe, Grant E; Rege, Robert V; Valentine, Rawson J; Jones, Daniel J; Tesfay, Seifu; Thal, Erwin R


    Resident work hours may impact patient care. We hypothesized that "call-associated" acute sleep deprivation has no effect on technical dexterity as measured on a minimally invasive surgery trainer, virtual reality (MIST VR) surgical simulator. Thirty-five surgical residents were prospectively evaluated pre-call (rested), on-call (rested), and post-call (acutely sleep deprived). Participants completed questionnaires regarding sleep hours and level of fatigue. Technical skill was assessed using the MIST VR. Speed, errors, and economy of motion were automatically recorded by the MIST VR computer simulator. Data were analyzed by paired Student t test and analysis of variance. Estimated hours of sleep and subjective indicators of fatigue were different between rested and sleep-deprived residents. The number of errors and time to complete all tasks increased at the post-call assessment. Resident work schedules lead to sleep deprivation and fatigue. Call-associated sleep deprivation and fatigue are associated with increased technical errors in the performance of simulated laparoscopic surgical skills.

  20. Systematic review of the implementation of simulation training in surgical residency curriculum. (United States)

    Kurashima, Yo; Hirano, Satoshi


    We reviewed the literature regarding the specific methods and strategies for implementing simulation-based training into the modern surgical residency curriculum. Residency programs are still struggling with how best to implement it into their curricula from a practical viewpoint. A systematic review was performed using Ovid MEDLINE, EMBASE, PubMed, PsycINFO, Web of Science, and other resources for studies involving the use of simulation for technical skills training in the surgical residency curriculum. Studies were selected based on the integration of simulation into the curriculum and/or a description of the details of implementation and the resources required. In total, 2533 unique citations were retrieved based on this search, and 31 articles met the inclusion criteria. Most simulators were focused on laparoscopic procedures, and training occurred most often in a skills lab. The assessment of skills consisted mostly of speed of task completion. Only 4 studies addressed issues of cost, and 6 programs mentioned human resources without any mention of skills center personnel or administrative support. All of the studies described the nature of the simulation training, but very few commented on how it was actually implemented and what was needed from organizational, administrative and logistical perspectives.

  1. Exploring Surgeons' Perceptions of the Role of Simulation in Surgical Education: A Needs Assessment

    Directory of Open Access Journals (Sweden)

    Marcia Clark


    Full Text Available Introduction: The last two decades have seen the adoption of simulation-based surgical education in various disciplines. The current study’s goal was to perform a needs assessment using the results to inform future curricular planning and needs of surgeons and learners. Methods: A survey was distributed to 26 surgeon educators and interviews were conducted with 8 of these surgeons.  Analysis of survey results included reliability and descriptive statistics. Interviews were analyzed for thematic content with a constant comparison technique, developing coding and categorization of themes. Results: The survey response rate was 81%. The inter-item reliability, according to Cronbach’s alpha was 0.81 with strongest agreement for statements related to learning new skills, training new residents and the positive impact on patient safety and learning.   There was less strong agreement for maintenance of skills, improving team functioning and reducing teaching in the operating room. Interview results confirmed those themes from the survey and highlighted inconsistencies for identified perceived barriers and a focus on acquisition of skills only.  Interview responses specified concerns with integrating simulation into existing curricula and the need for more evaluation as a robust educational strategy. Conclusion: The findings were summarized in four themes: 1 use of simulation, 2 integration into curriculum, 3 leadership, and 4 understanding gaps in simulation use. This study exemplifies a mixed-methods approach to planning a surgical simulation program through a general needs assessment.

  2. Bicipital tuberosity bone characteristics in surgical reattachment of the distal biceps: anatomical and radiological study. (United States)

    Lázaro-Amorós, Alexandre; Tomás-Batlle, Xavier; Ballesteros-Betancourt, José; Guillermo, José Ríos; Gómez-Bonsfills, Xavier; de la Vall, Xavier Cardona-Morera; Llusà-Pérez, Manuel


    The aim of this study was to measure the cortical thickness and bone density of the different parts of the bicipital tuberosity, to evaluate the importance of these variables on resistance to pulling out of distal biceps tendon reinsertion implants. Sixteen cadaveric arms were used for this study. A multiple detector computed tomography was performed in each proximal radius. Bone thickness and density of anterior, posterior cortex and anterior trabecular bone were measured in proximal, medial and distal parts of the bicipital tuberosity. Statistical and concordance analyses of results were performed. In our specimens, the medial and distal parts of the anterior cortex and the anterior trabecular bone were thicker, mean 11.3 mm SD 2.72 and 11.17 mm SD 3.05, with a significant difference when compared to the proximal part; mean 10.3 mm SD 2.35, of radial tuberosity. The three posterior segments where all thicker compared to the anterior cortex (proximal 3.15 SD 1.31; medial 3.33 SD 1.5; distal 3.34 SD 1.43 mm), but without statistical differences between them. The measured bone density was equivalent in the three portions of the anterior cortex and trabecular bone [proximal 1924.63 SD 547.22; medial 1848.19 SD 538.59; distal 2100.47 SD 396.32 Hounsfield units (HU)]. The posterior cortex was denser compared to the anterior cortex and the anterior trabecular bone in all the segments (proximal 1962.63 SD 223.57; medial 1907.16 SD 232.08; distal 1987.06 SD 189.12 HU), but without statistical differences between the three parts. Based on the results of this anatomic study which have demonstrated that anterior cortex and anterior trabecular bone of the medial and distal regions of the bicipital tuberosity are thicker than proximal part, we postulate that these segments could give better pulling out resistance to monocortical implants. Our findings suggest that the strongest parts of the bicipital tuberosity are the proximal and medial parts of the posterior cortex. We

  3. Accuracy of Image-guided Surgical Systems at the Lateral Skull Base as Clinically Assessed Using Bone-Anchored Hearing Aid Posts as Surgical Targets (United States)

    Balachandran, Ramya; Fitzpatrick, J. Michael


    Objective Image-guided surgical (IGS) technology has been clinically available for over a decade. To date, no acceptable standard exists for reporting the accuracy of IGS systems, especially for lateral skull base applications. We present a validation method that uses the post from bone anchored hearing aid (BAHA) patients as a target. We then compare the accuracy of two IGS systems—one using laser skin-surface scanning (LSSS) and another using a non-invasive fiducial frame (FF) attached to patient via dental bite-block (DBB) for registration. Study design Prospective. Setting Tertiary referral center. Patients Six BAHA patients who had adequate dentition for creation of a DBB. Intervention(s) For each patient, a dental impression was obtained, and a customized DBB was made to hold a FF. Temporal bone CT scans were obtained with the patient wearing the DBB, FF, and a customized marker on the BAHA post. In a mock OR, CT scans were registered to operative anatomy using two methods: (a) LSSS, (b) FF. Main outcome measure(s) For each patient and each system, the position of the BAHA marker in the CT scan and in the mock OR (using optical measurement technology) were compared and the distances between them are reported to demonstrate accuracy. Results Accuracy (mean ± standard deviation) was 1.54 ± 0.63 mm for DBB registration and 3.21 ± 1.02 mm for LSSS registration. Conclusions An IGS system using FF registration is more accurate than one using LSSS (p = 0.03, two-sided Student's t-test). BAHA patients provide a unique patient population upon which IGS systems may be validated. PMID:18836389

  4. Three-Dimensional Printing and Surgical Simulation for Preoperative Planning of Deformity Correction in Foot and Ankle Surgery. (United States)

    Jastifer, James R; Gustafson, Peter A

    A paucity of published data is available describing the methods for the integration of 3-dimensional (3D) printing technology and surgical simulation into orthopedic surgery. The cost of this technology has decreased and the ease of use has increased, making routine use of 3D printed models and surgical simulation for difficult orthopedic problems a realistic option. We report the use of 3D printed models and surgical simulation for preoperative planning and patient education in the case of deformity correction in foot and ankle surgery using open source, free software. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  5. Surgical simulation tasks challenge visual working memory and visual-spatial ability differently. (United States)

    Schlickum, Marcus; Hedman, Leif; Enochsson, Lars; Henningsohn, Lars; Kjellin, Ann; Felländer-Tsai, Li


    New strategies for selection and training of physicians are emerging. Previous studies have demonstrated a correlation between visual-spatial ability and visual working memory with surgical simulator performance. The aim of this study was to perform a detailed analysis on how these abilities are associated with metrics in simulator performance with different task content. The hypothesis is that the importance of visual-spatial ability and visual working memory varies with different task contents. Twenty-five medical students participated in the study that involved testing visual-spatial ability using the MRT-A test and visual working memory using the RoboMemo computer program. Subjects were also trained and tested for performance in three different surgical simulators. The scores from the psychometric tests and the performance metrics were then correlated using multivariate analysis. MRT-A score correlated significantly with the performance metrics Efficiency of screening (p = 0.006) and Total time (p = 0.01) in the GI Mentor II task and Total score (p = 0.02) in the MIST-VR simulator task. In the Uro Mentor task, both the MRT-A score and the visual working memory 3-D cube test score as presented in the RoboMemo program (p = 0.02) correlated with Total score (p = 0.004). In this study we have shown that some differences exist regarding the impact of visual abilities and task content on simulator performance. When designing future cognitive training programs and testing regimes, one might have to consider that the design must be adjusted in accordance with the specific surgical task to be trained in mind.

  6. Surgical management of complaints due to independent bone fragments in Osgood-Schlatter disease (apophysitis of the tuberosity of the tibia). (United States)

    Cser, I; Lénárt, G


    The surgical treatment of complaints due to independent bone parts in Osgood-Schlatter disease is described. Operations inducing the removal of the independent bone piece, the abrasion of the exostosis and the excision of inflamed connective tissue in their environment, were performed in 21 cases. By the intervention all patients could be relieved from their complaints. The pains are supposed to be due to inflammation caused by irritation on the surrounding region.

  7. A review of training research and virtual reality simulators for the da Vinci surgical system. (United States)

    Liu, May; Curet, Myriam


    PHENOMENON: Virtual reality simulators are the subject of several recent studies of skills training for robot-assisted surgery. Yet no consensus exists regarding what a core skill set comprises or how to measure skill performance. Defining a core skill set and relevant metrics would help surgical educators evaluate different simulators. This review draws from published research to propose a core technical skill set for using the da Vinci surgeon console. Publications on three commercial simulators were used to evaluate the simulators' content addressing these skills and associated metrics. An analysis of published research suggests that a core technical skill set for operating the surgeon console includes bimanual wristed manipulation, camera control, master clutching to manage hand position, use of third instrument arm, activating energy sources, appropriate depth perception, and awareness of forces applied by instruments. Validity studies of three commercial virtual reality simulators for robot-assisted surgery suggest that all three have comparable content and metrics. However, none have comprehensive content and metrics for all core skills. INSIGHTS: Virtual reality simulation remains a promising tool to support skill training for robot-assisted surgery, yet existing commercial simulator content is inadequate for performing and assessing a comprehensive basic skill set. The results of this evaluation help identify opportunities and challenges that exist for future developments in virtual reality simulation for robot-assisted surgery. Specifically, the inclusion of educational experts in the development cycle alongside clinical and technological experts is recommended.

  8. Comparative assessment of surgeons' task performance and surgical ergonomics associated with conventional and modified flank positions: a simulation study. (United States)

    Fan, Yu; Kong, Gaiqing; Meng, Yisen; Tan, Shutao; Wei, Kunlin; Zhang, Qian; Jin, Jie


    Flank position is extensively used in retroperitoneoscopic urological practice. Most surgeons follow the patients' position in open approaches. However, surgical ergonomics of the conventional position in the retroperitoneoscopic surgery is poor. We introduce a modified position and evaluated task performance and surgical ergonomics of both positions with simulated surgical tasks. Twenty-one novice surgeons were recruited to perform four tasks: bead transfer, ring transfer, continuous suturing, and cutting a circle. The conventional position was simulated by setting an endo-surgical simulator parallel to the long axis of a surgical desk. The modified position was simulated by rotating the simulator 30° with respect to the long axis of the desk. The outcome measurements include task performance measures, kinematic measures for body alignment, surface electromyography, relative loading between feet, and subjective ratings of fatigue. We observed significant improvements in both task performance and surgical ergonomics parameters under the modified position. For all four tasks, subjects finished tasks faster with higher accuracy (p ergonomics part: (1) The angle between the upper body and the head was decreased by 7.4 ± 1.7°; (2) The EMG amplitude collected from shoulders and left lumber was significantly lower (p ergonomics. With a simulated surgery, we demonstrated that our modified position could significantly improve task performance and surgical ergonomics. Further studies are still warranted to validate these benefits for both patients and surgeons.

  9. Factors associated with simulator-assessed laparoscopic surgical skills of veterinary students. (United States)

    Kilkenny, Jessica J; Singh, Ameet; Kerr, Carolyn L; Khosa, Deep K; Fransson, Boel A


    OBJECTIVE To determine whether simulator-assessed laparoscopic skills of veterinary students were associated with training level and prior experience performing nonlaparoscopic veterinary surgery and other activities requiring hand-eye coordination and manual dexterity. DESIGN Experiment. SAMPLE 145 students without any prior laparoscopic surgical or fundamentals of laparoscopic surgery (FLS) simulator experience in years 1 (n = 39), 2 (34), 3 (39), and 4 (33) at a veterinary college. PROCEDURES A questionnaire was used to collect data from participants regarding experience performing veterinary surgery, playing video games, and participating in other activities. Participants performed a peg transfer, pattern cutting, and ligature loop-placement task on an FLS simulator, and FLS scores were assigned by an observer. Scores were compared among academic years, and correlations between amounts of veterinary surgical experience and FLS scores were assessed. A general linear model was used to identify predictors of FLS scores. RESULTS Participants were predominantly female (75%), right-hand dominant (92%), and between 20 and 29 years of age (98%). No significant differences were identified among academic years in FLS scores for individual tasks or total FLS score. Scores were not significantly associated with prior surgical or video game experience. Participants reporting no handicraft experience had significantly lower total FLS scores and FLS scores for task 2 than did participants reporting a lot of handicraft experience. CONCLUSIONS AND CLINICAL RELEVANCE Prior veterinary surgical and video game experience had no influence on FLS scores in this group of veterinary students, suggesting that proficiency of veterinary students in FLS may require specific training.

  10. Simulation study of axial ultrasound transmission in heterogeneous cortical bone model (United States)

    Takano, Koki; Nagatani, Yoshiki; Matsukawa, Mami


    Ultrasound propagation in a heterogeneous cortical bone was studied. Using a bovine radius, the longitudinal wave velocity distribution in the axial direction was experimentally measured in the MHz range. The bilinear interpolation and piecewise cubic Hermite interpolation methods were applied to create a three-dimensional (3D) precise velocity model of the bone using experimental data. By assuming the uniaxial anisotropy of the bone, the distributions of all elastic moduli of a 3D heterogeneous model were estimated. The elastic finite-difference time-domain method was used to simulate axial ultrasonic wave propagation. The wave propagation in the initial model was compared with that in the thinner model, where the inner part of the cortical bone model was removed. The wave front of the first arriving signal (FAS) slightly depended on the heterogeneity in each model. Owing to the decrease in bone thickness, the propagation behavior also changed and the FAS velocity clearly decreased.

  11. A mechanical evaluation of implants placed with different surgical techniques into the trabecular bone of goats.

    NARCIS (Netherlands)

    Shalabi, M.M.; Wolke, J.G.C.; Ruijter, A.J. de; Jansen, J.A.


    The aim of the study was to assess the effects of surgical technique and implant surface roughness on implant fixation. A total of 48 screw implants with machined or etched surface topographies were placed into the femoral condyles of goats. The implant sites were prepared by a conventional

  12. Bone Indices in Patients with Non-Surgical Hypoparathyroidism and Pseudohypoparathyroidism

    DEFF Research Database (Denmark)

    Underbjerg, Line; Sikjær, Tanja Tvistholm; Rejnmark, Lars

    Objective: Both non-surgical hypoparathyroidism (NS-HypoPT) and pseudohypoparathyroidism (Ps-HypoPT) are rare diseases. As patients with NS-HypoPT lack PTH they have an elevated BMD compared to normal background population. Patients with Ps-HypoPT on the other hand have despite peripheral...

  13. [3D Virtual Reality Laparoscopic Simulation in Surgical Education - Results of a Pilot Study]. (United States)

    Kneist, W; Huber, T; Paschold, M; Lang, H


    The use of three-dimensional imaging in laparoscopy is a growing issue and has led to 3D systems in laparoscopic simulation. Studies on box trainers have shown differing results concerning the benefit of 3D imaging. There are currently no studies analysing 3D imaging in virtual reality laparoscopy (VRL). Five surgical fellows, 10 surgical residents and 29 undergraduate medical students performed abstract and procedural tasks on a VRL simulator using conventional 2D and 3D imaging in a randomised order. No significant differences between the two imaging systems were shown for students or medical professionals. Participants who preferred three-dimensional imaging showed significantly better results in 2D as wells as in 3D imaging. First results on three-dimensional imaging on box trainers showed different results. Some studies resulted in an advantage of 3D imaging for laparoscopic novices. This study did not confirm the superiority of 3D imaging over conventional 2D imaging in a VRL simulator. In the present study on 3D imaging on a VRL simulator there was no significant advantage for 3D imaging compared to conventional 2D imaging. Georg Thieme Verlag KG Stuttgart · New York.

  14. The results of surgical treatment of proximal long segment tracheal stenosis using bilateral hyoid bone cutting with suprahyoid release

    Directory of Open Access Journals (Sweden)

    khadivi E


    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Post-intubation tracheal stenosis is a serious problem and surgical resection is the method of choice in long segment tracheal stenosis treatment. The aim of this study was to review the results of surgical treatment of long segment post intubation tracheal stenosis and the role of bilateral hyoid bone cutting in supra- hyoid release technique."n"nMethods: Between 2004 to 2008, 14 patients with proximal long segment tracheal stenosis with resection of more than 40% of trachea length were evaluated regarding surgical technique and post-operative results."n"nResults: The mean age of patients was 22.2±0.4 years. Etiology in all patients were head trauma and prolonged intubation and all patients had tracheostomy at the time of trearment. Average time between surgery and first admission was 4.5±0.5 months. Average length of stenosis and resected segment were 3.6±0.5 and 4.3±0.5cm respectively. Average increased length of trachea after bilateral hyoid bone cutting was 1.1±0.3cm. Postoperative complications occurred in one patient with wound infection, and 4 patients had stenosis recurrence which was treated in 3 patients using multiple dilation. Quality of life 2 years after surgery in 71% of patients were

  15. Virtual reality simulation for the operating room: proficiency-based training as a paradigm shift in surgical skills training. (United States)

    Gallagher, Anthony G; Ritter, E Matt; Champion, Howard; Higgins, Gerald; Fried, Marvin P; Moses, Gerald; Smith, C Daniel; Satava, Richard M


    To inform surgeons about the practical issues to be considered for successful integration of virtual reality simulation into a surgical training program. The learning and practice of minimally invasive surgery (MIS) makes unique demands on surgical training programs. A decade ago Satava proposed virtual reality (VR) surgical simulation as a solution for this problem. Only recently have robust scientific studies supported that vision A review of the surgical education, human-factor, and psychology literature to identify important factors which will impinge on the successful integration of VR training into a surgical training program. VR is more likely to be successful if it is systematically integrated into a well-thought-out education and training program which objectively assesses technical skills improvement proximate to the learning experience. Validated performance metrics should be relevant to the surgical task being trained but in general will require trainees to reach an objectively determined proficiency criterion, based on tightly defined metrics and perform at this level consistently. VR training is more likely to be successful if the training schedule takes place on an interval basis rather than massed into a short period of extensive practice. High-fidelity VR simulations will confer the greatest skills transfer to the in vivo surgical situation, but less expensive VR trainers will also lead to considerably improved skills generalizations. VR for improved performance of MIS is now a reality. However, VR is only a training tool that must be thoughtfully introduced into a surgical training curriculum for it to successfully improve surgical technical skills.

  16. Effects of vacuum suctioning and strategic drape tenting on oxygen concentration in a simulated surgical field. (United States)

    Kung, Theodore A; Kong, Sarah W; Aliu, Oluseyi; Azizi, Jahan; Kai, Salim; Cederna, Paul S


    To investigate the isolated and combined effects of vacuum suctioning and strategic drape tenting on oxygen concentration in an experimental setting. Experimental. Clinical simulation center of a university-affiliated hospital. Mannequin simulation of a patient undergoing facial surgery under sedation anesthesia. Supplemental oxygen was delivered via nasal cannula. Vacuum suctioning and strategic drape tenting. The experimental trials entailed measuring oxygen concentration around the nasal cannula continuously either in the presence or absence of a standard operating room vacuum suction system and strategic tenting of surgical drapes. The primary outcome was the time required for oxygen concentration to reach 21%. In the control group (without suction or strategic tenting), a mean time of 180 seconds elapsed until the measured oxygen concentration reached 21% after cessation of oxygen delivery. Use of a vacuum suction device alone (110 seconds; P vacuum suction device during surgery will lower local oxygen concentration, and this in turn may decrease the risk of operating room fires. Although strategic tenting of surgical drapes has a theoretical benefit to decreasing the pooling of oxygen around the surgical site, further investigation is necessary before its routine use is recommended. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. [Effects of Chinese Bushen Zhuanggu medicine on bone loss in female rats after simulated weightlessness]. (United States)

    Sun, Ping; Huang, Zhen; Cai, De-Hong; He, Lei


    To study the effect of Bushen Zhuanggu, the traditional Chinese medicine for reinforcing kidney and strengthening bone, on bone loss in female rats after simulated weightlessness. Thirty-six female SD rats were randomly divided into 3 groups, namely normal control group (group A) and two groups of weightlessness simulated by tail suspension (groups B and C). Group C were treated with the Chinese medicine, while groups A and B were given the same dose of normal saline. The experiment lasted 28 days, and all rats were allowed to drink water freely. In the rats of group B, serum bone Gla protein (BGP), alkaline phosphatase (ALP), estradiol (E(2)) and P content and femur bone mineral content (BMD) were significantly lower than those in group A (P<0.01, P<0.05), whereas serum calcium concentration was markedly higher than that in group A (P<0.01). In rats of group C, serum BGP, ALP, E2 and P content and femur BMD were significantly higher than those in group B (P<0.01, P<0.05), but serum calcium concentration was markedly lower (P<0.01). This Chinese prescription can stimulate bone formation and reduce bone loss in female rats subjected to simulated weightlessness.

  18. Presentation of automated procedural guidance in surgical simulation: results of two randomised controlled trials. (United States)

    Wijewickrema, S; Zhou, Y; Ioannou, I; Copson, B; Piromchai, P; Yu, C; Briggs, R; Bailey, J; Kennedy, G; O'Leary, S


    To investigate the effectiveness and usability of automated procedural guidance during virtual temporal bone surgery. Two randomised controlled trials were performed to evaluate the effectiveness, for medical students, of two presentation modalities of automated real-time procedural guidance in virtual reality simulation: full and step-by-step visual presentation of drillable areas. Presentation modality effectiveness was determined through a comparison of participants' dissection quality, evaluated by a blinded otologist, using a validated assessment scale. While the provision of automated guidance on procedure improved performance (full presentation, p = 0.03; step-by-step presentation, p presentation modalities was vastly different (full presentation, 3.73 per cent; step-by-step presentation, 60.40 per cent). Automated procedural guidance in virtual temporal bone surgery is effective in improving trainee performance. Step-by-step presentation of procedural guidance was engaging, and therefore more likely to be used by the participants.

  19. Mineralization behavior and interface properties of BG-PVA/bone composite implants in simulated body fluid. (United States)

    Ma, Yanxuan; Zheng, Yudong; Huang, Xiaoshan; Xi, Tingfei; Lin, Xiaodan; Han, Dongfei; Song, Wenhui


    Due to the non-bioactivity and poor conjunction performance of present cartilage prostheses, the main work here is to develop the bioactive glass-polyvinyl alcohol hydrogel articular cartilage/bone (BG-PVA/bone) composite implants. The essential criterion for a biomaterial to bond with living bone is well-matched mechanical properties as well as biocompatibility and bioactivity. In vitro studies on the formation of a surface layer of carbonate hydroxyl apatite (HCA) and the corresponding variation of the properties of biomaterials are imperative for their clinical application. In this paper, the mineralization behavior and variation of the interface properties of BG-PVA/bone composites were studied in vitro by using simulated body fluid (SBF). The mineralization and HCA layer formed on the interface between the BG-PVA hydrogel and bone in SBF could provide the composites with bioactivity and firmer combination. The compression property, shear strength and interface morphology of BG-PVA/bone composite implants varying with the immersion time in SBF were characterized. Also, the influence laws of the immersion time, content of BG in the composites and aperture of bones to the mineralization behavior and interface properties were investigated. The good mineralization behavior and enhanced conjunction performance of BG-PVA/bone composites demonstrated that this kind of composite implant might be more appropriate cartilage replacements.

  20. Evaluation of 4 mm implants in mandibular edentulous patients with reduced bone height. Surgical preliminary results

    Directory of Open Access Journals (Sweden)

    J.L. Calvo-Guirado


    Full Text Available Aim: Growing evidence has suggested the utility of short dental implants for oral reconstructive procedures in clinical situations of limited vertical bone height. The aim of this short comunication was to evaluate the clinical use of implants < 10 mm in length and to determine short implant-supported prosthesis success in the atrophic jaw. Materials and methods: Six women and three men were recruited for the treatment of edentulous mandibles. A total of 6 implants were inserted in each patient: two anterior implants of conventional lenght and four posterior 4 mm Titanium Zirconium (TiZr implants. The insertion torque and bone denisty were evaluated. Results: The mean insertion torque for the 4 mm implants was lower than for conventional ones, without any statistical difference. Moreover, most of the patients (88% showed a D2 bone type. Conclusion: The provision of short implant-supported prostheses in patients with atrophic alveolar ridges appears to be a successful treatment option in the short term; however, more scientific evidence is needed for the long term.

  1. Update on Simulation-Based Surgical Training and Assessment in Ophthalmology

    DEFF Research Database (Denmark)

    Thomsen, Ann Sofia S; Subhi, Yousif; Kiilgaard, Jens Folke


    Library, and Web of Science) and was completed on March 1, 2014. Overall, the included trials were divided into animal, cadaver, inanimate, and virtual-reality models. Risk of bias was assessed using the Cochrane Collaboration's tool. Validity evidence was evaluated using a modern validity framework......; 4 trials (65 participants) evaluated the effect of simulation-based training on patient-related outcomes. Because of heterogeneity of the studies, it was not possible to conduct a quantitative analysis. CONCLUSIONS: The methodologic rigor of trials investigating simulation-based surgical training...... in ophthalmology is inadequate. To ensure effective implementation of training models, evidence-based knowledge of validity and efficacy is needed. We provide a useful tool for implementation and evaluation of research in simulation-based training....


    Directory of Open Access Journals (Sweden)

    V. V. Rerikh


    Full Text Available Surgical treatment of 177 patients with monolocal fractures of thoracic and lumbar vertebral bodies was performed using transpedicular fixation (n=17, transpedicular fixation and osteoplasty (n=101, vertebroplasty (n=48 or kyphoplasty (n=ll. Restoration of support ability of the fractured osteoporotic vertebrae within ventral column by means of plasty particularly in combination with internal fixation allows achievement of better clinical outcomes, improvement of the quality of life in patients in the early and late periods after surgery.

  3. Teaching surgical skills in obstetrics using a cesarean section simulator – bringing simulation to life

    Directory of Open Access Journals (Sweden)

    Venkata Sujatha Vellanki


    Full Text Available Venkata Sujatha Vellanki1, Sarath Babu Gillellamudi21Department of Obstetrics and Gynaecology 2Department of General Surgery Kamineni Institute of Medical Sciences, Sreepuram, Narketpally, Nalgonda, Andhra Pradesh, IndiaPurpose: Cesarean section is the most common surgery performed in obstetrics. Incorporating a simulation model into training provides a safe, low-stress environment in which students can gain skills and receive feedback. The purpose of this study was to determine the effectiveness of obstetrics simulator training for medical students doing their internship.Methods: Twenty-five students posted in the Department of Obstetrics and Gynecology received a formal lecture on cesarean section and demonstration of the procedure on a mannequin in the first week of their internship, The study group (n = 12 practiced their skills on an obstetrics simulator under the direct supervision of a faculty member. The control group received no simulator-based training (n = 13 or further instruction. All students were asked to complete a prevalidated questionnaire to assess their level of confidence in performing the procedure after the educational session.Results: Compared with their peers in the study, students in the simulator group were significantly more likely to define the steps of cesarean section (91% vs 61.5%, and were comfortable in assisting cesarean section (100% vs 46.15% as they were able to identify the layers of abdomen opened during cesarean section. All 12 students reported this as an excellent experience.Conclusion: We were able to construct an inexpensive cesarean section trainer that facilitates instruction in cesarean section technique in a low-stress environment.Keywords: simulation, obstetrics, medical students

  4. Simulated weightlessness and synbiotic diet effects on rat bone mechanical strength (United States)

    Sarper, Hüseyin; Blanton, Cynthia; DePalma, Jude; Melnykov, Igor V.; Gabaldón, Annette M.


    This paper reports results on exposure to simulated weightlessness that leads to a rapid decrease in bone mineral density known as spaceflight osteopenia by evaluating the effectiveness of dietary supplementation with synbiotics to counteract the effects of skeletal unloading. Forty adult male rats were studied under four different conditions in a 2 × 2 factorial design with main effects of diet (synbiotic and control) and weight condition (unloaded and control). Hindlimb unloading was performed at all times for 14 days followed by 14 days of recovery (reambulation). The synbiotic diet contained probiotic strains Lactobacillus acidophilus and Lactococcus lactis lactis and prebiotic fructooligosaccharide. This paper also reports on the development of a desktop three-point bending device to measure the mechanical strength of bones from rats subjected to simulated weightlessness. The importance of quantifying bone resistance to breakage is critical when examining the effectiveness of interventions against osteopenia resulting from skeletal unloading, such as astronauts experience, disuse or disease. Mechanical strength indices provide information beyond measures of bone density and microarchitecture that enhance the overall assessment of a treatment's potency. In this study we used a newly constructed three-point bending device to measure the mechanical strength of femur and tibia bones from hindlimb-unloaded rats fed an experimental synbiotic diet enriched with probiotics and fermentable fiber. Two calculated outputs for each sample were Young's modulus of elasticity and fracture stress. Bone major elements (calcium, magnesium, and phosphorous) were quantified using ICP-MS analysis. Hindlimb unloading was associated with a significant loss of strength in the femur, and with significant reductions in major bone elements. The synbiotic diet did not protect against these unloading effects. Tibia strength and major elements were not reduced by hindlimb unloading, as was

  5. A comparative analysis and guide to virtual reality robotic surgical simulators. (United States)

    Julian, Danielle; Tanaka, Alyssa; Mattingly, Patricia; Truong, Mireille; Perez, Manuela; Smith, Roger


    Since the US Food and Drug Administration approved robotically assisted surgical devices for human surgery in 2000, the number of surgeries utilizing this innovative technology has risen. In 2015, approximately 650 000 robot-assisted procedures were performed worldwide. Surgeons must be properly trained to safely transition to using such innovative technology. Multiple virtual reality robotic simulators are now commercially available for educational and training purposes. There is a need for comparative evaluations of these simulators to aid users in selecting an appropriate device for their purposes. We conducted a comparison of the design and capabilities of all dedicated simulators of the da Vinci robot - the da Vinci Skills Simulator (dVSS), dV-Trainer (dVT), Robotic Skills Simulators (RoSS) and the RobotiX Mentor. This paper provides the base specifications of the hardware and software, with an emphasis on the training capabilities of each system. Each simulator contains a large number of training exercises for skills development: dVSS n = 40, dVT n = 65, RoSS n = 52, RobotiX Mentor n = 31. All four offer 3D visual images but use different display technologies. The dVSS leverages the real robotic surgical console to provide visualization, hand controls and foot pedals. The dVT, RoSS and RobotiX Mentor created simulated versions of all of these control systems. Each includes systems management services that allow instructors to collect, export and analyze the scores of students using the simulators. This study provides comparative information on the four simulators' functional capabilities. Each device offers unique advantages and capabilities for training robotic surgeons. Each has been the subject of validation experiments, which have been published in the literature. But those do not provide specific details on the capabilities of the simulators, which are necessary for an understanding sufficient to select the one best suited for an organization

  6. Simulated Space Radiation and Weightlessness: Vascular-Bone Coupling Mechanisms to Preserve Skeletal Health (United States)

    Globus, R. K.; Alwood, J.; Tahimic, C.; Schreurs, A.-S.; Shirazi-Fard, Y.; Terada, M.; Zaragoza, J.; Truong, T.; Bruns, K.; Castillo, A.; hide


    We examined experimentally the effects of radiation and/or simulated weightlessness by hindlimb unloading on bone and blood vessel function either after a short period or at a later time after transient exposures in adult male, C57Bl6J mice. In sum, recent findings from our studies show that in the short term, ionizing radiation and simulate weightlessness cause greater deficits in blood vessels when combined compared to either challenge alone. In the long term, heavy ion radiation, but not unloading, can lead to persistent, adverse consequences for bone and vessel function, possibly due to oxidative stress-related pathways.

  7. Sawbones laboratory in orthopedic surgical training

    Directory of Open Access Journals (Sweden)

    Bandar M. Hetaimish


    Full Text Available Sawbones are artificial bones designed to simulate the bone architecture, as well as the bone’s physical properties. The incorporation of sawbones simulation laboratories in many orthopedic training programs has provided the residents with flexibility in learning and scheduling that align with their working hour limitations. This review paper deliberates the organization of sawbones simulation in orthopedic surgical training to enhance trainee’s future learning. In addition, it explores the implications of sawbones simulation in orthopedic surgical teaching and evaluation. It scrutinizes the suitability of practicing on sawbones at the simulation laboratory to improve orthopedic trainee’s learning. This will be followed with recommendations for future enhancement of sawbones simulation-based learning in orthopedic surgical training.

  8. Simulation-based education: understanding the socio-cultural complexity of a surgical training 'boot camp'. (United States)

    Cleland, Jennifer; Walker, Kenneth G; Gale, Michael; Nicol, Laura G


    The focus of simulation-based education (SBE) research has been limited to outcome and effectiveness studies. The effect of social and cultural influences on SBE is unclear and empirical work is lacking. Our objective in this study was to explore and understand the complexity of context and social factors at a surgical boot camp (BC). A rapid ethnographic study, employing the theoretical lenses of complexity and activity theory and Bourdieu's concept of 'capital', to better understand the socio-cultural influences acting upon, and during, two surgical BCs, and their implications for SBE. Over two 4-day BCs held in Scotland, UK, an observer and two preceptors conducted 81 hours of observations, 14 field interviews and 11 formal interviews with faculty members (n = 10, including the lead faculty member, session leaders and junior faculty members) and participants (n = 19 core surgical trainees and early-stage residents). Data collection and inductive analysis for emergent themes proceeded iteratively. This paper focuses on three analytical themes. First, the complexity of the surgical training system and wider health care education context, and how this influenced the development of the BC. Second, participants' views of the BC as a vehicle not just for learning skills but for gaining 'insider information' on how best to progress in surgical training. Finally, the explicit aim of faculty members to use the Scottish Surgical Bootcamp to welcome trainees and residents into the world of surgery, and how this occurred. To the best of our knowledge, this is the first empirical study of a surgical BC that takes a socio-cultural approach to exploring and understanding context, complexities, uncertainties and learning associated with one example of SBE. Our findings suggest that a BC is as much about social and cultural processes as it is about individual, cognitive and acquisitive learning. Acknowledging this explicitly will help those planning similar enterprises and

  9. Numerical simulations of post-surgical flow and thrombosis in basilar artery aneurysms (United States)

    Seshadhri, Santhosh; Lawton, Michael; Boussel, Loic; Saloner, David; Rayz, Vitaliy


    Surgical treatment of basilar artery aneurysms presents a major challenge since it is crucial to preserve the flow to the vital brainstem perforators branching of the basilar artery. In some cases, basilar aneurysms can be treated by clipping vessels in order to induce flow reduction and aneurysm thrombosis. Patient-specific CFD models can provide guidance to clinicians by simulating postoperative flows resulting from alternative surgeries. Several surgical options were evaluated for four basilar aneurysm patients. Patient-specific models were generated from preoperative MR angiography and MR velocimetry data and modified to simulate different procedures. The Navier-Stokes equations were solved with a finite-volume solver Fluent. Virtual contrast injections were simulated by solving the advection-diffusion equation in order to estimate the flow residence time and determine thrombus-prone regions. The results indicated on procedures that reduce intra-aneurysmal velocities and flow regions which are likely to become thrombosed. Thus CFD modeling can help improve the outcome of surgeries altering the flow in basilar aneurysms.

  10. Effect of surgical drill guide and irrigans temperature on thermal bone changes during drilling implant sites - thermographic analysis on bovine ribs. (United States)

    Marković, Aleksa; Lazić, Zoran; Mišić, Tijana; Šćepanović, Miodrag; Todorović, Aleksandar; Thakare, Kaustubh; Janjić, Bojan; Vlahović, Zoran; Glišić, Mirko


    During drilling implant sites, mechanical energy is converted into thermal one resulting in transient rise in temperature of surrounding bone. The temperature of 47°C exeeding one minute impairs osseointegration, compromises mechanical properties of the local bone and could cause early implant failure. This in vitro study aimed to assess the effect of surgical drill guide and temperature of irrigans on thermal changes of the local bone during drilling implant sites, and to test the influence of irrigans temperature on the temperature of surgical drill guide. A total of 48 specimens obtained from bovine ribs were randomly allocated to four experimental conditions according to the 2 x 2 factorial design: drill guide (with or without) and saline (at 25°C or 5°C). Real-time infrared thermography was used as a method for temperature measurement. The primary outcome was bone temperature change during drilling implant sites measured at 3 osteotomy depths, whereas the second one was change in the temperature of the drill guide. Data were analyzed by Brunner and Langer nonparametric analysis and Wilcoxon test. The effect of drill guide on the changes of bone temperature was significant at the entrance of osteotomy, whereas the effect of saline temperature was significant at all osteotomy levels (p 0.05). Guided surgery and irrigation with saline at 25°C were associated with the highest bone temperature increase. Increase in drill guide temperature was significantly higher when saline at 25°C was used (p Guided implant site preparation generates higher temperature of the local bone than conventional drilling, not exceeding the threshold for thermal bone necrosis. Although saline at room temperature provides sufficient heat control during drilling, cooled saline is more effective regardless the use of surgical drill guide.

  11. The current practice trends in pediatric bone-anchored hearing aids in Canada: a national clinical and surgical practice survey (United States)


    Background Since the introduction of bone-anchored hearing aids (BAHAs) in the 1980s, the practices of surgeons who implant these hearing aids have become varied; different indications and surgical techniques are utilized depending on the surgeon and institution. The objective of the current study is to describe the clinical and surgical practices of otolaryngologists in Canada who perform pediatric BAHA operations. Methods A detailed practice questionnaire was devised and sent to all members of the Canadian Society of Otolaryngology-Head and Neck Surgery. Those who performed pediatric BAHA surgeries were asked to participate. Results Twelve responses were received (response rate of 80%). All of the respondents identified congenital aural atresia to be an indication for pediatric BAHAs. Other indications were chronic otitis externa or media with hearing loss (92%), allergic reactions to conventional hearing aids (75%), congenital fixation or anomaly of ossicular chain (67%), and unilateral deafness (25%). Minor complications, such as skin reactions, were reported in 25% of cases, while major complications were very rare. There was great variability with regards to surgical techinque and post-operative management. The extent of financial support for the BAHA hardware and device also varied between provinces, and even within the same province. Conclusion There is a lack of general consensus regarding pediatric BAHA surgeries in Canada. With such a small community of otolaryngologists performing this procedure, we are hopeful that this survey can serve as an impetus for a national collaboration to establish a set of general management principles and inspire multi-site research ventures. PMID:23815797

  12. Surgical technique: Computer-generated custom jigs improve accuracy of wide resection of bone tumors. (United States)

    Khan, Fazel A; Lipman, Joseph D; Pearle, Andrew D; Boland, Patrick J; Healey, John H


    Manual techniques of reproducing a preoperative plan for primary bone tumor resection using rudimentary devices and imprecise localization techniques can result in compromised margins or unnecessary removal of unaffected tissue. We examined whether a novel technique using computer-generated custom jigs more accurately reproduces a preoperative resection plan than a standard manual technique. Using CT images and advanced imaging, reverse engineering, and computer-assisted design software, custom jigs were designed to precisely conform to a specific location on the surface of partially skeletonized cadaveric femurs. The jigs were used to perform a hemimetaphyseal resection. We performed CT scans on six matched pairs of cadaveric femurs. Based on a primary bone sarcoma model, a joint-sparing, hemimetaphyseal wide resection was precisely outlined on each femur. For each pair, the resection was performed using the standard manual technique on one specimen and the custom jig-assisted technique on the other. Superimposition of preoperative and postresection images enabled quantitative analysis of resection accuracy. The mean maximum deviation from the preoperative plan was 9.0 mm for the manual group and 2.0 mm for the custom-jig group. The percentages of times the maximum deviation was greater than 3 mm and greater than 4 mm was 100% and 72% for the manual group and 5.6% and 0.0% for the custom-jig group, respectively. Our findings suggest that custom-jig technology substantially improves the accuracy of primary bone tumor resection, enabling a surgeon to reproduce a given preoperative plan reliably and consistently.

  13. [Comparative analysis and clinical experience with osteoplastic materials materials based on non-demineralized bone collagen and artificial hydroxylapatite at the close of bone defects in ambulatory surgical dentistry]. (United States)

    Dunaev, M V; Kitaev, V A; Matavkina, M V; Druzhinin, A E; Bubnov, A S


    In the presence of bone defects during surgery is not always performed osteoptastic material replenishment defect that leads to a lengthening of the timing healing, bone regeneration, and treatment outcome. Application of osteoplastic materials allows for faster treatment outcomes, accelerate the regeneration of bone tissue in the area of the defect. To examine the effectiveness of materials based on non-demineralized bone collagen and artificial hydroxylapatite when filling bone defects in outpatient surgical practice dentistry. 22 patients with bone defects of various localization using osteoplastic materials were examined and treated. In our study, two groups were allocated on the etiology of bone loss: radicular cysts and chronic generalized periodontitis. Basic methods of diagnosis and monitoring of treatment in the work presented with the cone-beam computed tomography and digital orthopantomography. Application of the testing osteoplastic materials resulted in faster recovery times with a combination of bone defects using resorbable membranes or gel enriched fibrin. In all 22 patients both tested materials were well tolerated, allergic reactions were not identified. However, five patients with a history of endocrinological history, during which treatment material is applied on the basis non-demineralized bone collagen, the degree of osseointegration has been reduced by 25% compared to the somatic healthy patients. In 3 patients with a history of hematological history, during which the treatment was applied material on the basis of artificial hydroxyapatite, the regeneration of the bone defect was reduced by 20%, which suggests the influence of somatic condition of the patient on the regeneration of bone tissue. Currently, all patients are on dynamic monitoring, recurrence has been detected. Materials based on non-demineralized bone collagen and hydroxyapatite artificial equally successful during the replacement of the bone defect during surgery. However, the

  14. [Ex Vivo Testing of Mechanical Properties of Canine Metacarpal/Metatarsal Bones after Simulated Implant Removal]. (United States)

    Srnec, R; Fedorová, P; Pěnčík, J; Vojtová, L; Sedlinská, M; Nečas, A


    PURPOSE OF THE STUDY In a long-term perspective, it is better to remove implants after fracture healing. However, subsequent full or excessive loading of an extremity may result in refracture, and the bone with holes after screw removal may present a site with predilection for this. The aim of the study was to find ways of how to decrease risk factors for refracture in such a case. This involved support to the mechanical properties of a bone during its remodelling until defects following implant removal are repaired, using a material tolerated by bone tissue and easy to apply. It also included an assessment of the mechanical properties of a bone after filling the holes in it with a newly developed biodegradable polymer-composite gel ("bone paste"). The composite also has a prospect of being used to repair bony defects produced by pathological processes. MATERIAL AND METHODS Experiments were carried out on intact weight-bearing small bones in dogs. A total of 27 specimens of metacarpal/metatarsal bones were used for ex vivo testing. They were divided into three groups: K1 (n = 9) control undamaged bones; K2 (n = 9) control bones with iatrogenic damage simulating holes left after cortical screw removal; EXP (n = 9) experimental specimens in which simulated holes in bone were filled with the biodegradable self-hardening composite. The bone specimens were subjected to three-point bending in the caudocranial direction by a force acting parallel to the direction of drilling in their middiaphyses. The value of maximum load achieved (N) and the corresponding value of a vertical displacement (mm) were recorded in each specimen, then compared and statistically evaluated. RESULTS On application of a maximum load (N), all bone specimens broke in the mid-part of their diaphyses. In group K1 the average maximum force of 595.6 ± 79.5 N was needed to break the bone; in group K2 it was 347.6 ± 58.6 N; and in group EXP it was 458.3 ± 102.7 N. The groups with damaged bones, K2 and

  15. Surgical management of complete diaphyseal third metacarpal and metatarsal bone fractures: clinical outcome in 10 mature horses and 11 foals. (United States)

    Bischofberger, A S; Fürst, A; Auer, J; Lischer, C


    Osteosynthesis of third metacarpal (McIII) and third metatarsal (MtIII) bone fractures in horses is a surgical challenge and complications surrounding the repair are common. Retrospective studies evaluating surgical repair, complications and outcome are necessary to increase knowledge and improve success of long bone fracture repair in the horse. To evaluate clinical findings, surgical repair, post operative complications and outcome of 10 mature horses and 11 foals with McIII or MtIII fractures that were treated with open reduction and internal fixation (ORIF). Medical records were reviewed and follow-up information obtained by means of radiographs and/or telephone questionnaire. Survival was achieved in 62% of the horses (3 mature/10 foals). On long-term evaluation (> 6 months) 11 horses (2 mature/9 foals) were fit for their intended activity, one mature horse had a chronic low grade lameness, and one foal was lost to follow-up because it was sold. The main fracture types were simple transverse (333%) or simple oblique (28.6%) and 71.4% of the fractures were open, 3 Type I (one mature/2 foals) and 12 type II (7 mature/5 foals). The preoperative assessment revealed inadequate emergency treatment in 10 horses (5 mature/5 foals; 47.6%). Survival rate of horses with open fractures was 12.5% (1/8) in mature and 85.7% (6/7) in foals. Post operative incisional infection (4 mature, 3 foals) was only managed successfully in 2 foals. Fracture instability related to inadequate fracture fixation technique occurred in 4 horses (all mature) and was always associated with unsuccessful outcome. Age, bodyweight and infection are strongly associated with outcome in treatment of complete McIII/MtIII fractures. Rigid fixation using plates and screws can be successful in treatment of closed or open, complete diaphyseal McIII/MtIII fractures in mature horses and foals. Instable fixation, infection and a bodyweight > 320 kg are major risk factors for unsuccessful outcome.

  16. Need for Bone Grafts in the Surgical Treatment of Displaced Intra-Articular Calcaneal Fractures. (United States)

    Duymus, Tahir Mutlu; Mutlu, Serhat; Mutlu, Harun; Ozel, Omer; Guler, Olcay; Mahirogullari, Mahir

    Controversy is ongoing regarding the use of bone grafts to fill cavities that occur with collapse of the posterior facet in the joint and for repair of the calcaneal height with plating. The present study included 40 patients with 43 displaced intra-articular calcaneal fractures treated with open reduction and internal fixation from March 2009 to November 2013. In the present case-control study, the patients were separated into 2 groups: group A received an allograft (20 patients, 22 calcaneal fractures) and group B did not (20 patients, 21 calcaneal fractures). The calcaneal height and Böhler's angle were compared between the 2 groups. The final outcomes for all patients were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle hindfoot scale score and compared between the 2 groups. No significant differences were observed between the groups with regard to the basic demographic variables (p > .05). Using Sanders classification, 8 (18%) were type 2, 19 (44%) were type 3, and 16 (37%) were type 4 fractures. The comparisons between the 2 groups showed a loss of Böhler's angle and loss of calcaneal height that was significantly greater in group B (p  .05). In conclusion, although no differences were found in the clinical results between the 2 groups, more satisfactory radiologic results were obtained in group A, in which bone grafts were used. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  17. Simulation analysis for effects of bone loss on acceleration tolerance of human lumbar vertebra (United States)

    Ma, Honglei; Zhang, Feng; Zhu, Yu; Xiao, Yanhua; Wazir, Abrar


    The purpose of the present study was to analyze and predict the changes in acceleration tolerance of human vertebra as a result of bone loss caused by long-term space flight. A human L3-L4 vertebra FEM model was constructed, in which the cancellous bone was separated, and surrounding ligaments were also taken into account. The simulation results demonstrated that bone loss has more of an effect on the acceleration tolerance in x-direction. The results serve to aid in the creation of new acceleration tolerance standards, ensuring astronauts return home safely after long-term space flight. This study shows that more attention should be focused on the bone degradation of crew members and to create new protective designs for space capsules in the future.

  18. Influence of medical student career aims on ophthalmic surgical simulator performance (part of the international forum for ophthalmic simulation studies). (United States)

    Gillan, S N; Okhravi, N; O'Sullivan, F; Sullivan, P; Viswanathan, A; Saleh, G M


    To evaluate whether medical students who have expressed a strong desire to pursue ophthalmology as a career perform simulated ophthalmic surgical tasks to a higher level than medical students whose interests lie elsewhere. All participants were fourth or fifth year students at University College London (UCL) Medical School, London, UK. One cohort was recruited from the Moorfields Academy, an ophthalmic forum designed to enhance collaboration and innovation within the specialty. These students were therefore seen as highly motivated, expressing a desire to pursue a career in ophthalmology. The other cohort of students was invited to participate during their fourth year UCL Ophthalmology attachment, but expressed interest in non-ophthalmic disciplines. Participants carried out a single attempt of three modules on the Eyesi Surgical Simulator, and total and mean scores were calculated out of 100. 13 academy and 15 non-academy students were enrolled. The overall mean scores were 51/100 for the academy group, range 0-97, and 45.5/100 for the non-academy group, range 0-90 (p=0.49). Scores for precision testing, forceps training and capsulorrhexis training for academy versus non-academy were 45.8 versus 37.8 (p=0.61), 57.1 versus 52.3 (p=0.8) and 50.2 versus 46.4 (p=0.55), respectively. This study is the first to suggest that medical students with a strong career interest in ophthalmology do not perform microsurgical tasks to a higher level than medical students who have no goal in this area. This also indicates variation in scores between novices, which may serve as a pitfall in the use of simulators as a tool for entry into training. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to

  19. Evaluation of bone remodeling around single dental implants of different lengths: a mechanobiological numerical simulation and validation using clinical data. (United States)

    Sotto-Maior, Bruno Salles; Mercuri, Emílio Graciliano Ferreira; Senna, Plinio Mendes; Assis, Neuza Maria Souza Picorelli; Francischone, Carlos Eduardo; Del Bel Cury, Altair Antoninha


    Algorithmic models have been proposed to explain adaptive behavior of bone to loading; however, these models have not been applied to explain the biomechanics of short dental implants. Purpose of present study was to simulate bone remodeling around single implants of different lengths using mechanoregulatory tissue differentiation model derived from the Stanford theory, using finite elements analysis (FEA) and to validate the theoretical prediction with the clinical findings of crestal bone loss. Loading cycles were applied on 7-, 10-, or 13-mm-long dental implants to simulate daily mastication and bone remodeling was assessed by changes in the strain energy density of bone after a 3, 6, and 12 months of function. Moreover, clinical findings of marginal bone loss in 45 patients rehabilitated with same implant designs used in the simulation (n = 15) were computed to validate the theoretical results. FEA analysis showed that although the bone density values reduced over time in the cortical bone for all groups, bone remodeling was independent of implant length. Clinical data showed a similar pattern of bone resorption compared with the data generated from mathematical analyses, independent of implant length. The results of this study showed that the mechanoregulatory tissue model could be employed in monitoring the morphological changes in bone that is subjected to biomechanical loads. In addition, the implant length did not influence the bone remodeling around single dental implants during the first year of loading.

  20. Coaching Non-technical Skills Improves Surgical Residents' Performance in a Simulated Operating Room. (United States)

    Yule, Steven; Parker, Sarah Henrickson; Wilkinson, Jill; McKinley, Aileen; MacDonald, Jamie; Neill, Adrian; McAdam, Tim


    To investigate the effect of coaching on non-technical skills and performance during laparoscopic cholecystectomy in a simulated operating room (OR). Non-technical skills (situation awareness, decision making, teamwork, and leadership) underpin technical ability and are critical to the success of operations and the safety of patients in the OR. The rate of developing assessment tools in this area has outpaced development of workable interventions to improve non-technical skills in surgical training and beyond. A randomized trial was conducted with senior surgical residents (n = 16). Participants were randomized to receive either non-technical skills coaching (intervention) or to self-reflect (control) after each of 5 simulated operations. Coaching was based on the Non-Technical Skills For Surgeons (NOTSS) behavior observation system. Surgeon-coaches trained in this method coached participants in the intervention group for 10 minutes after each simulation. Primary outcome measure was non-technical skills, assessed from video by a surgeon using the NOTSS system. Secondary outcomes were time to call for help during bleeding, operative time, and path length of laparoscopic instruments. Non-technical skills improved in the intervention group from scenario 1 to scenario 5 compared with those in the control group (p = 0.04). The intervention group was faster to call for help when faced with unstoppable bleeding in the final scenario (no. 5; p = 0.03). Coaching improved residents' non-technical skills in the simulated OR compared with those in the control group. Important next steps are to implement non-technical skills coaching in the real OR and assess effect on clinically important process measures and patient outcomes. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  1. Using the Statecharts paradigm for simulation of patient flow in surgical care. (United States)

    Sobolev, Boris; Harel, David; Vasilakis, Christos; Levy, Adrian


    Computer simulation of patient flow has been used extensively to assess the impacts of changes in the management of surgical care. However, little research is available on the utility of existing modeling techniques. The purpose of this paper is to examine the capacity of Statecharts, a system of graphical specification, for constructing a discrete-event simulation model of the perioperative process. The Statecharts specification paradigm was originally developed for representing reactive systems by extending the formalism of finite-state machines through notions of hierarchy, parallelism, and event broadcasting. Hierarchy permits subordination between states so that one state may contain other states. Parallelism permits more than one state to be active at any given time. Broadcasting of events allows one state to detect changes in another state. In the context of the peri-operative process, hierarchy provides the means to describe steps within activities and to cluster related activities, parallelism provides the means to specify concurrent activities, and event broadcasting provides the means to trigger a series of actions in one activity according to transitions that occur in another activity. Combined with hierarchy and parallelism, event broadcasting offers a convenient way to describe the interaction of concurrent activities. We applied the Statecharts formalism to describe the progress of individual patients through surgical care as a series of asynchronous updates in patient records generated in reaction to events produced by parallel finite-state machines representing concurrent clinical and managerial activities. We conclude that Statecharts capture successfully the behavioral aspects of surgical care delivery by specifying permissible chronology of events, conditions, and actions.

  2. Numerical simulation of strain-adaptive bone remodelling in the ankle joint

    Directory of Open Access Journals (Sweden)

    Stukenborg-Colsman Christina


    Full Text Available Abstract Background The use of artificial endoprostheses has become a routine procedure for knee and hip joints while ankle arthritis has traditionally been treated by means of arthrodesis. Due to its advantages, the implantation of endoprostheses is constantly increasing. While finite element analyses (FEA of strain-adaptive bone remodelling have been carried out for the hip joint in previous studies, to our knowledge there are no investigations that have considered remodelling processes of the ankle joint. In order to evaluate and optimise new generation implants of the ankle joint, as well as to gain additional knowledge regarding the biomechanics, strain-adaptive bone remodelling has been calculated separately for the tibia and the talus after providing them with an implant. Methods FE models of the bone-implant assembly for both the tibia and the talus have been developed. Bone characteristics such as the density distribution have been applied corresponding to CT scans. A force of 5,200 N, which corresponds to the compression force during normal walking of a person with a weight of 100 kg according to Stauffer et al., has been used in the simulation. The bone adaptation law, previously developed by our research team, has been used for the calculation of the remodelling processes. Results A total bone mass loss of 2% in the tibia and 13% in the talus was calculated. The greater decline of density in the talus is due to its smaller size compared to the relatively large implant dimensions causing remodelling processes in the whole bone tissue. In the tibia, bone remodelling processes are only calculated in areas adjacent to the implant. Thus, a smaller bone mass loss than in the talus can be expected. There is a high agreement between the simulation results in the distal tibia and the literature regarding. Conclusions In this study, strain-adaptive bone remodelling processes are simulated using the FE method. The results contribute to a better

  3. Real-time surgical simulation for deformable soft-tissue objects with a tumour using Boundary Element techniques

    International Nuclear Information System (INIS)

    Wang, P; Becker, A A; Jones, I A; Glover, A T; Benford, S D; Vloeberghs, M


    A virtual-reality real-time simulation of surgical operations that incorporates the inclusion of a hard tumour is presented. The software is based on Boundary Element (BE) technique. A review of the BE formulation for real-time analysis of two-domain deformable objects, using the pre-solution technique, is presented. The two-domain BE software is incorporated into a surgical simulation system called VIRS to simulate the initiation of a cut on the surface of the soft tissue and extending the cut deeper until the tumour is reached.

  4. Assessment of laparoscopic psychomotor skills in interns using the MIST Virtual Reality Simulator: a prerequisite for those considering surgical training? (United States)

    Cope, Daron H; Fenton-Lee, Douglas


    Selection for surgical training in Australia is currently based on assessment of a structured curriculum vitae, referral reports from selected clinicians and an interview. The formal assessment of laparoscopic psychomotor skill and ability to attain skills is not currently a prerequisite for selection. The aim of this study was to assess the innate psychomotor skills of interns and also to compare interns with an interest in pursuing a surgical career to interns with those with no interest in pursuing a surgical career. Twenty-two interns were given the opportunity to carry out tasks on the Minimal Invasive Surgical Trainer, Virtual Reality (Mentice, Gothenburg, Sweden) Simulator. The candidates were required to complete six tasks, repeated six times each. Scores for each task were calculated objectively by the simulator software. Demographic data were similar between the two groups. Although some candidates who were interested in pursuing a surgical career performed poorly on the simulator, there was no significant difference when comparing the two groups. The Minimal Invasive Surgical Trainer, Virtual Reality (Mentice) Simulator provides an objective and comparable assessment of laparoscopic psychomotor skills. We can conclude that interns have varying inherent ability as judged by the simulator and this does not seem to have an influence on their career selection. There was no significant difference in the scores between the two groups. Interns with and without inherent abilities have aspirations to pursue surgical careers and their aptitude does not seem to influence this decision. Surgical colleges could use psychomotor ability assessments to recruit candidates to pursue a career in surgery. Trainees needing closer monitoring and additional training could be identified early and guided to achieve competency.

  5. Development and evaluation of a simulator-based laparoscopic training program for surgical novices. (United States)

    Nugent, Emmeline; Shirilla, Nicole; Hafeez, Adnan; O'Riordain, Diarmuid S; Traynor, Oscar; Harrison, Anthony M; Neary, Paul


    The use of simulation to train novice surgeons in laparoscopic skills is becoming increasingly popular. To maximize benefit from simulation, training needs to be delivered and assessed in a structured manner. This study aimed to define performance goals, demonstrate construct validity of the training program, and evaluate whether novice surgeons could reach the preset performance goals. Nine expert laparoscopic surgeons established performance goals for three basic modules of an augmented-reality laparoscopic simulator. The three laparoscopic modules were used by 40 novice surgeons and 40 surgical trainees (postgraduate years [PGYs] 1-4). The performance outcomes were analyzed across the different groups (novice, PGYs 1 and 2, PGYs 3 and 4, expert) to determine construct validity. Then 26 recruited novices trained on the three modules with the aim of reaching the performance goals. The results demonstrated a significant difference in performance between all levels of experience for time (p < 0.001), motion analysis (p < 0.001), and error score (p < 0.001), thus demonstrating construct validity. All 26 novice surgeons significantly improved in performance with repetition for the metrics of time (p < 0.001) and motion analysis (p < 0.001). For two of the modules, the proficiency goals were reached in fewer than 10 trials by 80% of the study participants. Basic skills in laparoscopic surgery can be learned and improved using proficiency-based simulation training. It is possible for novice surgeons to achieve predefined performance goals in a reasonable time frame.

  6. ChainMail based neural dynamics modeling of soft tissue deformation for surgical simulation. (United States)

    Zhang, Jinao; Zhong, Yongmin; Smith, Julian; Gu, Chengfan


    Realistic and real-time modeling and simulation of soft tissue deformation is a fundamental research issue in the field of surgical simulation. In this paper, a novel cellular neural network approach is presented for modeling and simulation of soft tissue deformation by combining neural dynamics of cellular neural network with ChainMail mechanism. The proposed method formulates the problem of elastic deformation into cellular neural network activities to avoid the complex computation of elasticity. The local position adjustments of ChainMail are incorporated into the cellular neural network as the local connectivity of cells, through which the dynamic behaviors of soft tissue deformation are transformed into the neural dynamics of cellular neural network. Experiments demonstrate that the proposed neural network approach is capable of modeling the soft tissues' nonlinear deformation and typical mechanical behaviors. The proposed method not only improves ChainMail's linear deformation with the nonlinear characteristics of neural dynamics but also enables the cellular neural network to follow the principle of continuum mechanics to simulate soft tissue deformation.

  7. The current state of bone loss research: data from spaceflight and microgravity simulators. (United States)

    Nagaraja, Mamta Patel; Risin, Diana


    Bone loss is a well documented phenomenon occurring in humans both in short- and in long-term spaceflights. This phenomenon can be also reproduced on the ground in human and animals and also modeled in cell-based analogs. Since space flights are infrequent and expensive to study the biomedical effects of microgravity on the human body, much of the known pathology of bone loss comes from experimental studies. The most commonly used in vitro simulators of microgravity are clinostats while in vivo simulators include the bed rest studies in humans and hindlimb unloading experiments in animals. Despite the numerous reports that have documented bone loss in wide ranges in multiple crew members, the pathology remains a key concern and development of effective countermeasures is still a major task. Thus far, the offered modalities have not shown much success in preventing or alleviating bone loss in astronauts and cosmonauts. The objective of this review is to capture the most recent research on bone loss from spaceflights, bed rest and hindlimb unloading, and in vitro studies utilizing cellular models in clinostats. Additionally, this review offers projections on where the research has to focus to ensure the most rapid development of effective countermeasures. Copyright © 2012 Wiley Periodicals, Inc.

  8. Effect of Gukang capsule-assisted surgical treatment on fracture healing, microcirculation and bone metabolism in elder patients with fracture of distal radius

    Directory of Open Access Journals (Sweden)

    Jian-Nian Wang


    Full Text Available Objective: To analyze the effect of Gukang capsule-assisted surgical treatment on fracture healing, microcirculation and bone metabolism in elder patients with fracture of distal radius. Methods: A total of 200 elderly patients with fracture of distal radius treated from September 2010 to September 2015 were randomly divided into observation group and control group (n=100. Control group received routine surgical treatment, and observation group underwent Gukang capsule-assisted surgical treatment. Fracture healing was compared between two groups, serum microcirculation and bone metabolism indexes were detected 1 week after operation, X-ray examination was performed 6 months after operation and imaging parameters were measured. Results: Regression time of postoperative affected-side limb swelling and radiographic healing time of broken ends of fractured bone of observation group were significantly shorter than those of control group; 1 week after operation, serum TXB2, CTX-I, CTX-II, RANK, RANKL and TRACP5b levels as well as TXB-2/6-Keto-PGF1α ratio of observation group were significantly lower than those of control group, and 6-Keto-PGF1α, ALP, OPG, PICP, BGP and 1,25(OH2D3 levels were significantly higher than those of control group. Conclusions: Gukang capsule-assisted surgery helps promote the fracture healing in elderly patients with fracture of distal radius and can improve microcirculation and bone metabolism.

  9. Finite element simulation of bone remodelling in human mandible around osseointegrated dental implant

    International Nuclear Information System (INIS)

    Lian, Z Q; Guan, H; Loo, Y C; Ivanovski, S; Johnson, N W


    Modern dental implant is a biocompatible titanium device surgically placed into a jawbone to support a prosthetic tooth crown in order to replace missing teeth. Implants are superior to conventional prostheses, in both function and long-term predictability. However, placement of an implant changes the normal mechanical environment of jawbone, which causes the bone density to redistribute and adapt to the new environment through a process of remodelling. This study aims to predict the density distribution in human jawbone around osseointegrated dental implant. Based on two popular, yet distinctive theories for bone remodelling, a new remodelling algorithm is proposed. The proposed algorithm is verified by a two-dimensional (2D) plate model. Then, a 2D finite element model of implant and jawbone is studied. The effects of two parameters, viz the reference value of strain energy density (SED) and 'lazy zone' region, on density distribution, are also examined. This study has demonstrated that consideration of the lazy zone, is less important than consideration of the stress and strain (quantified as SED) induced within the bone. Taking into account both 'lazy zone' effect and self-organisational control process, the proposed bone remodelling algorithm has overcome the shortcomings of the two existing theories.

  10. Bilateral diaphyseal bone cysts of the tibia mimicking shin splints in a young professional athlete--a case report and depiction of a less-invasive surgical technique. (United States)

    Toepfer, Andreas; Harrasser, Norbert; Lenze, Ulrich; Liska, Franz; Mühlhofer, Heinrich; von Eisenhart-Rothe, Rüdiger; Banke, Ingo J


    Medial tibial stress syndrome is one of the most common causes of exertional leg pain in runners whereas musculoskeletal tumors and tumor-like lesions are rare encounters in orthopedic sports medicine practice. Unicameral (simple) bone cyst is a well-known tumor-like lesions of the bone typically affecting children and adolescents. Bilateral occurrence is very rare though and has never been reported before in both tibiae. Failing to accurately diagnose a tumorous lesion can entail far-reaching consequences for both patients and physicians. We report the case of large bilateral unicameral bone cysts of the diaphyseal tibiae mimicking medial tibial stress syndrome in a 17-year old professional athlete. This is the first report of symmetric tibial unicameral bone cysts in the literature. The patient complained about persisting shin splint-like symptoms over 5 months despite comprehensive conservative treatment before MRI revealed extensive osteolytic bone lesions in both diaphyseal tibiae. The patient-tailored, less-invasive surgical procedure, allowing the patient to return to his competitive sports level symptom-free 3 months after surgery and to eventually qualify for this years Biathlon Junior World Championships, is outlined briefly. Pathogenesis and various treatment options for this entity will be discussed. This report will help to raise awareness for musculoskeletal tumors as differential diagnosis for therapy-refractory symptoms in young athletes and encourage medical staff involved in sports medicine and athlete support to perform early high quality imaging and initiate sufficient surgical treatment in similar cases. Moreover, our less-invasive surgical procedure aiming for a fast return to sports might be an optimal compromise between traditional open curettage with low risk of recurrence and a soft tissue-saving and bone-sparing minimal-invasive technique.

  11. Comparing video games and laparoscopic simulators in the development of laparoscopic skills in surgical residents. (United States)

    Adams, Barbara J; Margaron, Franklin; Kaplan, Brian J


    The video game industry has become increasingly popular over recent years, offering photorealistic simulations of various scenarios while requiring motor, visual, and cognitive coordination. Video game players outperform nonplayers on different visual tasks and are faster and more accurate on laparoscopic simulators. The same qualities found in video game players are highly desired in surgeons. Our investigation aims to evaluate the effect of video game play on the development of fine motor and visual skills. Specifically, we plan to examine if handheld video devices offer the same improvement in laparoscopic skill as traditional simulators, with less cost and more accessibility. We performed an Institutional Review Board-approved study, including categorical surgical residents and preliminary interns at our institution. The residents were randomly assigned to 1 of 3 study arms, including a traditional laparoscopic simulator, XBOX 360 gaming console, or Nintendo DS handheld gaming system. After an introduction survey and baseline timed test using a laparoscopic surgery box trainer, residents were given 6 weeks to practice on their respective consoles. At the conclusion of the study, the residents were tested again on the simulator and completed a final survey. A total of 31 residents were included in the study, representing equal distribution of each class level. The XBOX 360 group spent more time on their console weekly (6 hours per week) compared with the simulator (2 hours per week), and Nintendo groups (3 hours per week). There was a significant difference in the improvement of the tested time among the 3 groups, with the XBOX 360 group showing the greatest improvement (p = 0.052). The residents in the laparoscopic simulator arm (n = 11) improved 4.6 seconds, the XBOX group (n = 10) improved 17.7 seconds, and the Nintendo DS group (n = 10) improved 11.8 seconds. Residents who played more than 10 hours of video games weekly had the fastest times on the simulator

  12. Finite element analysis and CT-based structural rigidity analysis to assess failure load in bones with simulated lytic defects. (United States)

    Anez-Bustillos, Lorenzo; Derikx, Loes C; Verdonschot, Nico; Calderon, Nathan; Zurakowski, David; Snyder, Brian D; Nazarian, Ara; Tanck, Esther


    There is an urgent need to improve the prediction of fracture risk for cancer patients with bone metastases. Pathological fractures that result from these tumors frequently occur in the femur. It is extremely difficult to determine the fracture risk even for experienced physicians. Although evolving, fracture risk assessment is still based on inaccurate predictors estimated from previous retrospective studies. As a result, many patients are surgically over-treated, whereas other patients may fracture their bones against expectations. We mechanically tested ten pairs of human cadaveric femurs to failure, where one of each pair had an artificial defect simulating typical metastatic lesions. Prior to testing, finite element (FE) models were generated and computed tomography rigidity analysis (CTRA) was performed to obtain axial and bending rigidity measurements. We compared the two techniques on their capacity to assess femoral failure load by using linear regression techniques, Student's t-tests, the Bland-Altman methodology and Kendall rank correlation coefficients. The simulated FE failure loads and CTRA predictions showed good correlation with values obtained from the experimental mechanical testing. Kendall rank correlation coefficients between the FE rankings and the CTRA rankings showed moderate to good correlations. No significant differences in prediction accuracy were found between the two methods. Non-invasive fracture risk assessment techniques currently developed both correlated well with actual failure loads in mechanical testing suggesting that both methods could be further developed into a tool that can be used in clinical practice. The results in this study showed slight differences between the methods, yet validation in prospective patient studies should confirm these preliminary findings. © 2013.

  13. High-grade MRI bone oedema is common within the surgical field in rheumatoid arthritis patients undergoing joint replacement and is associated with osteitis in subchondral bone

    DEFF Research Database (Denmark)

    McQueen, F M; Gao, A; Ostergaard, M


    OBJECTIVES: MRI bone oedema has been observed in early and advanced RA and may represent a cellular infiltrate (osteitis) in subchondral bone. We studied MRI scans from RA patients undergoing surgery, seeking to identify regions of bone oedema and examine its histopathological equivalent in resec...

  14. The validity of take-home surgical simulators to enhance resident technical skill proficiency. (United States)

    Uccelli, Joe; Kahol, Kanav; Ashby, Aaron; Smith, Marshall; Ferrara, John


    It is unknown whether surgical residents who learn minimal-access surgery skills in an unstructured environment (ie, at home), will develop a technical skill set that rivals that of those trained in the more traditional, structured learning environment. Seven surgery residents were provided structured learning through didactic and hands-on skills training sessions and consistent supervision throughout training. A second group of 7 residents participated in an unstructured learning curriculum of training without supervision. End points were determined at the end of training using a standardized simulator based on predetermined performance measures. Both groups achieved high task scores, with comparable scores on gesture proficiency, hand movement smoothness, instrument movement smoothness, errors, and time elapsed. There was no significant difference between group differences in final skills scores. Unstructured learning is equally effective in delivering quality skills training when compared with structured training. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Second Life™: a novel simulation platform for the training of surgical residents. (United States)

    Flowers, Michael G; Aggarwal, Rajesh


    A virtual world is a three-dimensional, computer-generated, simulated environment. Human users create "avatars," or virtual projections of themselves, in order to explore this virtual environment and interact with the objects and structures inside it. Second Life™ is one such virtual world accessible freely via the internet, which has been used to construct a virtual hospital complete with reception areas, changing rooms, offices, and hospital wards. Early pioneering studies have demonstrated the advantages of using virtual worlds in the education of surgical residents in a number of ways, from introductions to the clinical environment, initial patient assessment, and managing adverse outcomes, to gaining informed consent, hospital-wide training, and medical device development.

  16. Visual-spatial ability is more important than motivation for novices in surgical simulator training: a preliminary study. (United States)

    Schlickum, Marcus; Hedman, Leif; Felländer-Tsai, Li


    To investigate whether surgical simulation performance and previous video gaming experience would correlate with higher motivation to further train a specific simulator task and whether visual-spatial ability would rank higher in importance to surgical performance than the above. It was also examined whether or not motivation would correlate with a preference to choose a surgical specialty in the future and if simulator training would increase the interest in choosing that same work field. Motivation and general interest in surgery was measured pre- and post-training in 30 medical students at Karolinska Institutet who were tested in a laparoscopic surgical simulator in parallel with measurement of visual-spatial ability and self-estimated video gaming experience. Correlations between simulator performance metrics, visual-spatial ability and motivation were statistically analyzed using regression analysis. A good result in the first simulator trial correlated with higher self-determination index (r =-0.46, p=0.05) in male students. Visual-spatial ability was the most important underlying factor followed by intrinsic motivation score and finally video gaming experience (p=0.02, p=0.05, p=0.11) regarding simulator performance in male students. Simulator training increased interest in surgery when studying all subjects (p=0.01), male subjects (p=0.02) as well as subjects with low video gaming experience (p=0.02). This preliminary study highlights individual differences regarding the effect of simulator training on motivation that can be taken into account when designing simulator training curricula, although the sample size is quite small and findings should be interpreted carefully.

  17. Validation of composite finite elements efficiently simulating elasticity of trabecular bone. (United States)

    Schwen, Lars Ole; Wolfram, Uwe


    Patient-specific analyses of the mechanical properties of bones become increasingly important for the management of patients with osteoporosis. The potential of composite finite elements (CFEs), a novel FE technique, to assess the apparent stiffness of vertebral trabecular bone is investigated in this study. Segmented volumes of cylindrical specimens of trabecular bone are compared to measured volumes. Elasticity under uniaxial loading conditions is simulated; apparent stiffnesses are compared to experimentally determined values. Computational efficiency is assessed and recommendations for simulation parameters are given. Validating apparent uniaxial stiffnesses results in concordance correlation coefficients 0.69 ≤ r(c) ≤ 0.92 for resolutions finer than 168 μm, and an average error of 5.8% between experimental and numerical results at 24 μm resolution. As an application, the code was used to compute local, macroscopic stiffness tensors for the trabecular structure of a lumbar vertebra. The presented technique allows for computing stiffness using smooth FE meshes at resolutions that are well achievable in peripheral high resolution quantitative CT. Therefore, CFEs could be a valuable tool for the patient-specific assessment of bone stiffness.

  18. Ultrasonic guided waves dispersion reversal for long bone thickness evaluation: a simulation study. (United States)

    Xu, Kailiang; Liu, Chengcheng; Ta, Dean


    It has been shown that ultrasonic guided waves have great potentials for long cortical bone evaluation. However, due to the multimodal dispersion, the received signals usually contain several mixed guided modes, which highly complicates the mode separation and signal processing. In the study, we showed that the use of dispersion reversal excitation allows the self-compensation of the dispersive modes in the long cortical bone. Two-dimension finite-difference time-domain (2D-FDTD) method was employed to simulate the propagation of two fundamental guided modes, symmetrical S0 and anti-symmetrical A0, in the long cortical bones. It was demonstrated that the pulse-like modes of S0 and A0 can be detected under the dispersion reversal excitations. The simulations also illustrated that the proposed dispersion reversal method can be used to evaluate the cortical thickness. Results are promising for the application of dispersion reversal method in ultrasonic assessment of the long cortical bone.

  19. Effects of Human Adipose-derived Stem Cells and Platelet-rich Plasma on Healing Response of Canine Alveolar Surgical Bone Defects

    Directory of Open Access Journals (Sweden)

    Reyhaneh Shafieian


    Full Text Available Background: Due to the known disadvantages of autologous bone grafting, tissue engineering approaches have become an attractive method for ridge augmentation in dentistry. To the best of our knowledge, this is the first study conducted to evaluate the potential therapeutic capacity of PRP-assisted hADSCs seeded on HA/TCP granules on regenerative healing response of canine alveolar surgical bone defects. This could offer a great advantage to alternative approaches of bone tissue healing-induced therapies at clinically chair-side procedures. Methods: Cylindrical through-and-through defects were drilled in the mandibular plate of 5 mongrel dogs and filled randomly as following: I- autologous crushed mandibular bone, II- no filling material, III- HA/TCP granules in combination with PRP, and IV- PRP-enriched hADSCs seeded on HA/TCP granules. After the completion of an 8-week period of healing, radiographic, histological and histomorphometrical analysis of osteocyte number, newly-formed vessels and marrow spaces were used for evaluation and comparison of the mentioned groups. Furthermore, the buccal side of mandibular alveolar bone of every individual animal was drilled as normal control samples (n=5. Results: Our results revealed that hADSCs subcultured on HA/TCP granules in combination with PRP significantly promoted bone tissue regeneration as compared with those defects treated only with PRP and HA/TCP granules (P

  20. Human maxillary sinus floor elevation as a model for bone regeneration enabling the application of one-step surgical procedures

    NARCIS (Netherlands)

    Farre-Guasch, E.; Prins, H.J.; Overman, J.R.; ten Bruggenkate, C.M.; Schulten, E.A.J.M.; Helder, M.N.; Klein-Nulend, J.


    Bone loss in the oral and maxillofacial region caused by trauma, tumors, congenital disorders, or degenerative diseases is a health care problem worldwide. To restore (reconstruct) these bone defects, human or animal bone grafts or alloplastic (synthetic) materials have been used. However, several

  1. Human Maxillary Sinus Floor Elevation as a Model for Bone Regeneration Enabling the Application of One-Step Surgical Procedures

    NARCIS (Netherlands)

    Farre-Guasch, E.; Prins, H.J.; Overman, J.R.; ten Bruggenkate, C.M.; Schulten, E.A.J.M.; Helder, M.N.; Klein-Nulend, J.


    Bone loss in the oral and maxillofacial region caused by trauma, tumors, congenital disorders, or degenerative diseases is a health care problem worldwide. To restore (reconstruct) these bone defects, human or animal bone grafts or alloplastic (synthetic) materials have been used. However, several

  2. An integrated approach to endoscopic instrument tracking for augmented reality applications in surgical simulation training. (United States)

    Loukas, Constantinos; Lahanas, Vasileios; Georgiou, Evangelos


    Despite the popular use of virtual and physical reality simulators in laparoscopic training, the educational potential of augmented reality (AR) has not received much attention. A major challenge is the robust tracking and three-dimensional (3D) pose estimation of the endoscopic instrument, which are essential for achieving interaction with the virtual world and for realistic rendering when the virtual scene is occluded by the instrument. In this paper we propose a method that addresses these issues, based solely on visual information obtained from the endoscopic camera. Two different tracking algorithms are combined for estimating the 3D pose of the surgical instrument with respect to the camera. The first tracker creates an adaptive model of a colour strip attached to the distal part of the tool (close to the tip). The second algorithm tracks the endoscopic shaft, using a combined Hough-Kalman approach. The 3D pose is estimated with perspective geometry, using appropriate measurements extracted by the two trackers. The method has been validated on several complex image sequences for its tracking efficiency, pose estimation accuracy and applicability in AR-based training. Using a standard endoscopic camera, the absolute average error of the tip position was 2.5 mm for working distances commonly found in laparoscopic training. The average error of the instrument's angle with respect to the camera plane was approximately 2°. The results are also supplemented by video segments of laparoscopic training tasks performed in a physical and an AR environment. The experiments yielded promising results regarding the potential of applying AR technologies for laparoscopic skills training, based on a computer vision framework. The issue of occlusion handling was adequately addressed. The estimated trajectory of the instruments may also be used for surgical gesture interpretation and assessment. Copyright © 2013 John Wiley & Sons, Ltd.

  3. Structural degradation of acrylic bone cements due to in vivo and simulated aging. (United States)

    Hughes, Kerry F; Ries, Michael D; Pruitt, Lisa A


    Acrylic bone cement is the primary load-bearing material used for the attachment of orthopedic devices to adjoining bone. Degradation of acrylic-based cements in vivo results in a loss of structural integrity of the bone-cement-prosthesis interface and limits the longevity of cemented orthopedic implants. The purpose of this study is to investigate the effect of in vivo aging on the structure of the acrylic bone cement and to develop an in vitro artificial aging protocol that mimics the observed degradation. Three sets of retrievals are examined in this study: Palacos brand cement retrieved from hip replacements, and Simplex brand cement retrieved from both hip and knee replacement surgeries. In vitro aging is performed using oxidative and acidic environments on three acrylic-based cements: Palacos, Simplex, and CORE. Gel permeation chromatography (GPC) and Fourier transform infrared spectroscopy (FTIR) are used to examine the evolution of molecular weight and chemical species within the acrylic cements due to both in vivo and simulated aging. GPC analysis indicates that molecular weight is degraded in the hip retrievals but not in the knee retrievals. Artificial aging in an oxidative environment best reproduces this degradation mechanism. FTIR analysis indicates that there exists a chemical evolution within the cement due to in vivo and in vitro aging. These findings are consistent with scission-based degradation schemes in the cement. Based on the results of this study, a pathway for structural degradation of acrylic bone cement is proposed. The findings from this investigation have broad applicability to acrylic-based cements and may provide guidance for the development of new bone cements that resist degradation in the body. Copyright 2003 Wiley Periodicals, Inc.

  4. Innovative approach using interprofessional simulation to educate surgical residents in technical and nontechnical skills in high-risk clinical scenarios. (United States)

    Nicksa, Grace A; Anderson, Cristan; Fidler, Richard; Stewart, Lygia


    The Accreditation Council for Graduate Medical Education core competencies stress nontechnical skills that can be difficult to evaluate and teach to surgical residents. During emergencies, surgeons work in interprofessional teams and are required to perform certain procedures. To obtain proficiency in these skills, residents must be trained. To educate surgical residents in leadership, teamwork, effective communication, and infrequently performed emergency surgical procedures with the use of interprofessional simulations. SimMan 3GS was used to simulate high-risk clinical scenarios (15-20 minutes), followed by debriefings with real-time feedback (30 minutes). A modified Oxford Non-Technical Skills scale (score range, 1-4) was used to assess surgical resident performance during the first half of the academic year (July-December 2012) and the second half of the academic year (January-June 2013). Anonymous online surveys were used to solicit participant feedback. Simulations were conducted in the operating room, intensive care unit, emergency department, ward, and simulation center. A total of 43 surgical residents (postgraduate years [PGYs] 1 and 2) participated in interdisciplinary clinical scenarios, with other health care professionals (nursing, anesthesia, critical care, medicine, respiratory therapy, and pharmacy; mean number of nonsurgical participants/session: 4, range 0-9). Thirty seven surgical residents responded to the survey. Simulation of high-risk clinical scenarios: postoperative pulmonary embolus, pneumothorax, myocardial infarction, gastrointestinal bleeding, anaphylaxis with a difficult airway, and pulseless electrical activity arrest. Evaluation of resident skills: communication, leadership, teamwork, problem solving, situation awareness, and confidence in performing emergency procedures (eg, cricothyroidotomy). A total of 31 of 35 (89%) of the residents responding found the sessions useful. Additionally, 28 of 33 (85%) reported improved confidence

  5. Effects of testosterone replacement therapy on bone metabolism in male post-surgical hypogonadotropic hypogonadism: focus on the role of androgen receptor CAG polymorphism. (United States)

    Tirabassi, G; delli Muti, N; Gioia, A; Biagioli, A; Lenzi, A; Balercia, G


    The relationship between androgen receptor (AR) CAG polymorphism and bone metabolism is highly controversial. We, therefore, aimed to evaluate the independent role of AR CAG repeat polymorphism on bone metabolism improvement induced by testosterone replacement therapy (TRT) in male post-surgical hypogonadotropic hypogonadism, a condition frequently associated with hypopituitarism and in which the effects of TRT have to be distinguished from those resulting from concomitant administration of pituitary function replacing hormones. 12 men affected by post-surgical hypogonadotropic hypogonadism [mean duration of hypogonadism 8.3 ± 2.05 (SD) months] were retrospectively assessed before and after TRT (from 74 to 84 weeks after the beginning of therapy). The following measures were studied: parameters of bone metabolism [serum markers and bone mineral density (BMD)], pituitary dependent hormones and genetic analysis (AR CAG repeat number). Total testosterone, estradiol, free T4 (FT4) and insulin-like growth factor-1 (IGF-1) increased between the two phases, while follicle stimulating hormone (FSH) decreased. While serum markers did not vary significantly between the two phases, BMD improved slightly but significantly in all the studied sites. The number of CAG triplets correlated negatively and significantly with all the variations (Δ-) of BMDs. Conversely, Δ-testosterone correlated positively and significantly with all studied Δ-BMDs, while Δ-FSH, Δ-estradiol, Δ-FT4, and Δ-IGF-1 did not correlate significantly with any of the Δ-BMDs. Multiple linear regression analysis, after correction for Δ-testosterone, showed that CAG repeat length was negatively and significantly associated with ∆-BMD of all measured sites. Our data suggest that, in post-surgical male hypogonadotropic hypogonadism, shorter AR CAG tract is independently associated with greater TRT-induced improvement of BMD.

  6. Influence of surgical and prosthetic techniques on marginal bone loss around titanium implants. Part I: immediate loading in fresh extraction sockets. (United States)

    Berberi, Antoine N; Tehini, Georges E; Noujeim, Ziad F; Khairallah, Alexandre A; Abousehlib, Moustafa N; Salameh, Ziad A


    Delayed placement of implant abutments has been associated with peri-implant marginal bone loss; however, long-term results obtained by modifying surgical and prosthetic techniques after implant placement are still lacking. This study aimed to evaluate the marginal bone loss around titanium implants placed in fresh extraction sockets using two loading protocols after a 5-year follow-up period. A total of 36 patients received 40 titanium implants (Astra Tech) intended for single-tooth replacement. Implants were immediately placed into fresh extraction sockets using either a one-stage (immediate loading by placing an interim prosthesis into functional occlusion) or a two-stage prosthetic loading protocol (insertion of abutments after 8 weeks of healing time). Marginal bone levels relative to the implant reference point were evaluated at four time intervals using intraoral radiographs: at time of implant placement, and 1, 3, and 5 years after implant placement. Measurements were obtained from mesial and distal surfaces of each implant (α = 0.05). One-stage immediate implant placement into fresh extraction sockets resulted in a significant reduction in marginal bone loss (p implants after cementation of interim prostheses (p immediate loading of implants placed into fresh extraction sockets reduced marginal bone loss and did not compromise the success rate of the restorations. © 2014 by the American College of Prosthodontists.

  7. Transverse and Oblique Long Bone Fracture Evaluation by Low Order Ultrasonic Guided Waves: A Simulation Study. (United States)

    Li, Ying; Liu, Dan; Xu, Kailiang; Ta, Dean; Le, Lawrence H; Wang, Weiqi


    Ultrasonic guided waves have recently been used in fracture evaluation and fracture healing monitoring. An axial transmission technique has been used to quantify the impact of the gap breakage width and fracture angle on the amplitudes of low order guided wave modes S 0 and A 0 under a 100 kHz narrowband excitation. In our two dimensional finite-difference time-domain (2D-FDTD) simulation, the long bones are modeled as three layers with a soft tissue overlay and marrow underlay. The simulations of the transversely and obliquely fractured long bones show that the amplitudes of both S 0 and A 0 decrease as the gap breakage widens. Fixing the crack width, the increase of the fracture angle relative to the cross section perpendicular to the long axis enhances the amplitude of A 0, while the amplitude of S 0 shows a nonmonotonic trend with the decrease of the fracture angle. The amplitude ratio between the S 0 and A 0 modes is used to quantitatively evaluate the fracture width and angles. The study suggests that the low order guided wave modes S 0 and A 0 have potentials for transverse and oblique bone fracture evaluation and fracture healing monitoring.

  8. Basic airway skills acquisition using the American College of Surgeons/Association for Surgical Education medical student simulation-based surgical skills curriculum: Initial results. (United States)

    Muratore, Sydne; Kim, Michael; Olasky, Jaisa; Campbell, Andre; Acton, Robert


    The ACS/ASE Medical Student Simulation-Based Skills Curriculum was developed to standardize medical student training. This study aims to evaluate the feasibility and validity of implementing the basic airway curriculum. This single-center, prospective study of medical students participating in the basic airway module from 12/2014-3/2016 consisted of didactics, small-group practice, and testing in a simulated clinical scenario. Proficiency was determined by a checklist of skills (1-15), global score (1-5), and letter grade (NR-needs review, PS-proficient in simulation scenario, CP-proficient in clinical scenario). A proportion of students completed pre/post-test surveys regarding experience, satisfaction, comfort, and self-perceived proficiency. Over 16 months, 240 students were enrolled with 98% deemed proficient in a simulated or clinical scenario. Pre/post-test surveys (n = 126) indicated improvement in self-perceived proficiency by 99% of learners. All students felt moderately to very comfortable performing basic airway skills and 94% had moderate to considerable satisfaction after completing the module. The ACS/ASE Surgical Skills Curriculum is a feasible and effective way to teach medical students basic airway skills using simulation. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Difficult airway intubation simulation using Bonfils fiberscope and rigid fiberscope for surgical training. (United States)

    Dharmarajan, Harish; Liu, Yi-Chun Carol; Hippard, Helena Karlberg; Chandy, Binoy


    Pediatric otolaryngologists are frequently called to assist in difficult airway management in newborns with Pierre Robin Sequence (PRS) who have microretrognathia, glossoptosis, and an anterior larynx. The Bonfils fiberscope (BF) is a curved rigid scope designed to provide superior visualization in the anterior larynx. (1) to assess whether BF provides an improvement in intubation success rate, time to intubation, or airway visualization as compared to rigid fiberscope (RF) in a difficult airway simulation setting and (2) to determine whether a training program for BF can improve time to intubation through practice trials. Six right-handed trainees completed five trials on each of the three following airway models using the BF and RF: normal anatomy, anterior larynx and PRS. The normal larynx model was intubated only with RF. Main outcome measures were the time needed for tracheal intubation and Cormack-Lehane classification (1-4). The majority of the intubation trials showed a statistically significant difference between first and last completion times (p Cormack-Lehane classification measures, laryngeal visualization by the BF was better than RF in the PRS manikin (p < .0022) while there was no significant difference in grade scores for the anterior larynx manikin (p < .45). All six trainees reported an improved visualization of the larynx with the BF compared to the RF for both the anterior larynx and PRS manikins; at the end of the trial runs, all participants noted an improvement in comfort level using the BF. The difficult airway simulation model is feasible for surgical training. BF adds superior visualization of the anterior larynx in PRS. Otolaryngology training programs may include BF as a supplemental tool in addition to RF as a part of the airway equipment training since there is significant improvement in time to intubation with consecutive practice trials and superior laryngeal visualization. Copyright © 2017 Elsevier B.V. All rights

  10. Long-Term Follow-Up of Primary Medical Versus Surgical Treatment of Prolactinomas in Men: Effects on Hyperprolactinemia, Hypogonadism, and Bone Health. (United States)

    Andereggen, Lukas; Frey, Janine; Andres, Robert H; El-Koussy, Marwan; Beck, Jürgen; Seiler, Rolf W; Christ, Emanuel


    In men with prolactinomas, impaired bone density is the principle consequence of hyperprolactinemia-induced hypogonadism. Although dopamine agonists (DAs) are the first-line approach in prolactinomas, surgery can be considered in selected cases. In this study, we aimed to investigate the long-term control of hyperprolactinemia, hypogonadism, and bone health comparing primary medical and surgical therapy in men who had not had prior DA treatment. This is a retrospective case-note study of 44 consecutive men with prolactinomas and no prior DAs managed in a single tertiary referral center. Clinical, biochemical, and radiologic response to the first-line approach were analyzed in the 2 cohorts. Mean age at diagnosis was 47 years (range, 22-78 years). The prevalence of hypogonadism was 86%, and 27% of patients had pathologic bone density at baseline. The primary therapeutic strategy was surgery for 34% and DAs for 66% of patients. Median long-term follow-up was 63 months (range, 17-238 months). Long-term control of hyperprolactinemia required DAs in 53% of patients with primary surgical therapy, versus 90% of patients with primary medical therapy (P = 0.02). Hypogonadism was controlled in 73% of patients. The prevalence of patients with pathologic bone density was 37% at last follow-up, with no differences between the 2 therapeutic cohorts (P = 0.48). Despite control of hyperprolactinemia and hypogonadism in most patients independent of the primary treatment modality, the prevalence of impaired bone health status remains high, and osteodensitometry should be recommended. Copyright © 2016 Elsevier Inc. All rights reserved.


    Directory of Open Access Journals (Sweden)



    Full Text Available INTRODUCTION Clavicle fracture is one of the most common fracture presenting to the fracture clinic, accounting for about 5-10% of all the adult trauma reported but still the controversy exists with regards to the definitive management. AIM To evaluate the surgical outcome of nonunion clavicle in patients treated previously with surgical management or conservative management, using plate and slivers of autologous iliac crest corticocancellous bone. DESIGN Retrospective analysis of patients operated between May 2005 and February 2013 for nonunion of the clavicle. METHODS AND MATERIALS Twenty patients who were operated between May 2005 and February 2013 for nonunion of the clavicle at our hospital were recruited for our study and followup data was collected from our hospital records till their last outpatient visit. Inclusion criteria included patients with no evidence of radiological union, persistence of pain, cosmetic deformity, dysfunction or gross movement at the fracture site even after 16 weeks of conservative treatment or in cases of primary fixation failure. STATISTICAL ANALYSIS All Statistical analyses were made using Statistical Package Software for Social Sciences (SPSS version 17.0 software (Chicago, IL, USA for descriptive data. Chi2 test was used to compare the categorical data. RESULTS At the end of an average followup of 19 months, the average Visual Analogue Score for pain was 1.9±2.2 (range 0-6, the mean ASES score was 81±18.5 (51-100, and the mean Constant–Murley score was 80±17 (51-100. All the patients had a stable radiological union at the end of the followup period. There were no complications pertaining to the hardware or infection. CONCLUSION Treatment of nonunion of clavicle by using corticocancellous bone is well documented; however, use of iliac corticocancellous bone graft shaped in long slivers will give mechanical stability to the plate reconstruct in addition to providing a scaffold for new bone formation than

  12. 3D-printed soft-tissue physical models of renal malignancies for individualized surgical simulation: a feasibility study. (United States)

    Maddox, Michael M; Feibus, Allison; Liu, James; Wang, Julie; Thomas, Raju; Silberstein, Jonathan L


    To construct patient-specific physical three-dimensional (3D) models of renal units with materials that approximates the properties of renal tissue to allow pre-operative and robotic training surgical simulation, 3D physical kidney models were created (3DSystems, Rock Hill, SC) using computerized tomography to segment structures of interest (parenchyma, vasculature, collection system, and tumor). Images were converted to a 3D surface mesh file for fabrication using a multi-jet 3D printer. A novel construction technique was employed to approximate normal renal tissue texture, printers selectively deposited photopolymer material forming the outer shell of the kidney, and subsequently, an agarose gel solution was injected into the inner cavity recreating the spongier renal parenchyma. We constructed seven models of renal units with suspected malignancies. Partial nephrectomy and renorrhaphy were performed on each of the replicas. Subsequently all patients successfully underwent robotic partial nephrectomy. Average tumor diameter was 4.4 cm, warm ischemia time was 25 min, RENAL nephrometry score was 7.4, and surgical margins were negative. A comparison was made between the seven cases and the Tulane Urology prospectively maintained robotic partial nephrectomy database. Patients with surgical models had larger tumors, higher nephrometry score, longer warm ischemic time, fewer positive surgical margins, shorter hospitalization, and fewer post-operative complications; however, the only significant finding was lower estimated blood loss (186 cc vs 236; p = 0.01). In this feasibility study, pre-operative resectable physical 3D models can be constructed and used as patient-specific surgical simulation tools; further study will need to demonstrate if this results in improvement of surgical outcomes and robotic simulation education.

  13. INPRES (intraoperative presentation of surgical planning and simulation results): augmented reality for craniofacial surgery (United States)

    Salb, Tobias; Brief, Jakob; Welzel, Thomas; Giesler, Bjoern; Hassfeld, Steffan; Muehling, Joachim; Dillmann, Ruediger


    In this paper we present recent developments and pre-clinical validation results of our approach for augmented reality (AR, for short) in craniofacial surgery. A commercial Sony Glasstron display is used for optical see-through overlay of surgical planning and simulation results with a patient inside the operation room (OR). For the tracking of the glasses, of the patient and of various medical instruments an NDI Polaris system is used as standard solution. A complementary inside-out navigation approach has been realized with a panoramic camera. This device is mounted on the head of the surgeon for tracking of fiducials placed on the walls of the OR. Further tasks described include the calibration of the head-mounted display (HMD), the registration of virtual objects with the real world and the detection of occlusions in the object overlay with help of two miniature CCD cameras. The evaluation of our work took place in the laboratory environment and showed promising results. Future work will concentrate on the optimization of the technical features of the prototype and on the development of a system for everyday clinical use.

  14. Nonlinear finite element simulations of injuries with free boundaries: application to surgical wounds. (United States)

    Valero, C; Javierre, E; García-Aznar, J M; Gómez-Benito, M J


    Wound healing is a process driven by biochemical and mechanical variables in which a new tissue is synthesised to recover original tissue functionality. Wound morphology plays a crucial role in this process, as the skin behaviour is not uniform along different directions. In this work, we simulate the contraction of surgical wounds, which can be characterised as elongated and deep wounds. Because of the regularity of this morphology, we approximate the evolution of the wound through its cross section, adopting a plane strain hypothesis. This simplification reduces the complexity of the computational problem; while allows for a thorough analysis of the role of wound depth in the healing process, an aspect of medical and computational relevance that has not yet been addressed. To reproduce wound contraction, we consider the role of fibroblasts, myofibroblasts, collagen and a generic growth factor. The contraction phenomenon is driven by cell-generated forces. We postulate that these forces are adjusted to the mechanical environment of the tissue where cells are embedded through a mechanosensing and mechanotransduction mechanism. To solve the nonlinear problem, we use the finite element method (FEM) and an updated Lagrangian approach to represent the change in the geometry. To elucidate the role of wound depth and width on the contraction pattern and evolution of the involved species, we analyse different wound geometries with the same wound area. We find that deeper wounds contract less and reach a maximum contraction rate earlier than superficial wounds. Copyright © 2014 John Wiley & Sons, Ltd.

  15. The Mozart effect on task performance in a laparoscopic surgical simulator. (United States)

    Wiseman, Michael C


    The Mozart Effect is a phenomenon whereby certain pieces of music induce temporary enhancement in "spatial temporal reasoning." To determine whether the Mozart Effect can improve surgical performance, 55 male volunteers (mean age = 20.6 years, range = 16-27), novice to surgery, were timed as they completed an activity course on a laparoscopic simulator. Subjects were then randomized for exposure to 1 of 2 musical pieces by Mozart (n = 21) and Dream Theater (n = 19), after which they repeated the course. Following a 15-minute exposure to a nonmusical piece, subjects were exposed to one of the pieces and performed the activity course a third time. An additional group (n = 15) that was not corandomized performed the tasks without any exposure to music. The percent improvements in completion time between 3 successive trials were calculated for each subject and group means compared. In 2 of the tasks, subjects exposed to the Dream Theater piece achieved approximately 30% more improvement (26.7 ± 8.3%) than those exposed to the Mozart piece (20.2 ± 7.8%, P = .021) or to no music (20.4 ± 9.1%, P = .049). Distinct patterns of covariance between baseline performance and subsequent improvement were observed for the different musical conditions and tasks. The data confirm the existence of a Mozart Effect and demonstrate for the first time its practical applicability. Prior exposure to certain pieces may enhance performance in practical skills requiring spatial temporal reasoning.

  16. A qualitative and quantitative assessment for a bone marrow harvest simulator. (United States)

    Machado, Liliane S; Moraes, Ronei M


    Several approaches to perform assessment in training simulators based on virtual reality have been proposed. There are two kinds of assessment methods: offline and online. The main requirements related to online training assessment methodologies applied to virtual reality systems are the low computational complexity and the high accuracy. In the literature it can be found several approaches for general cases which can satisfy such requirements. An inconvenient about those approaches is related to an unsatisfactory solution for specific cases, as in some medical procedures, where there are quantitative and qualitative information available to perform the assessment. In this paper, we present an approach to online training assessment based on a Modified Naive Bayes which can manipulate qualitative and quantitative variables simultaneously. A special medical case was simulated in a bone marrow harvest simulator. The results obtained were satisfactory and evidenced the applicability of the method.

  17. Systematic Review of Voluntary Participation in Simulation-Based Laparoscopic Skills Training: Motivators and Barriers for Surgical Trainee Attendance. (United States)

    Gostlow, Hannah; Marlow, Nicholas; Babidge, Wendy; Maddern, Guy

    To examine and report on evidence relating to surgical trainees' voluntary participation in simulation-based laparoscopic skills training. Specifically, the underlying motivators, enablers, and barriers faced by surgical trainees with regard to attending training sessions on a regular basis. A systematic search of the literature (PubMed; CINAHL; EMBASE; Cochrane Collaboration) was conducted between May and July 2015. Studies were included on whether they reported on surgical trainee attendance at voluntary, simulation-based laparoscopic skills training sessions, in addition to qualitative data regarding participant's perceived barriers and motivators influencing their decision to attend such training. Factors affecting a trainee's motivation were categorized as either intrinsic (internal) or extrinsic (external). Two randomised control trials and 7 case series' met our inclusion criteria. Included studies were small and generally poor quality. Overall, voluntary simulation-based laparoscopic skills training was not well attended. Intrinsic motivators included clearly defined personal performance goals and relevance to clinical practice. Extrinsic motivators included clinical responsibilities and available free time, simulator location close to clinical training, and setting obligatory assessments or mandated training sessions. The effect of each of these factors was variable, and largely dependent on the individual trainee. The greatest reported barrier to attending voluntary training was the lack of available free time. Although data quality is limited, it can be seen that providing unrestricted access to simulator equipment is not effective in motivating surgical trainees to voluntarily participate in simulation-based laparoscopic skills training. To successfully encourage participation, consideration needs to be given to the factors influencing motivation to attend training. Further research, including better designed randomised control trials and large

  18. The use of cone-beam computed tomography and virtual reality simulation for pre-surgical practice in endodontic microsurgery. (United States)

    Suebnukarn, S; Rhienmora, P; Haddawy, P


    To design and evaluate the impact of virtual reality (VR) pre-surgical practice on the performance of actual endodontic microsurgery.   The VR system operates on a laptop with a 1.6-GHz Intel processor and 2 GB of main memory. Volumetric cone-beam computed tomography (CBCT) data were acquired from a fresh cadaveric porcine mandible prior to endodontic microsurgery. Ten inexperienced endodontic trainees were randomized as to whether they performed endodontic microsurgery with or without virtual pre-surgical practice. The VR simulator has microinstruments to perform surgical procedures under magnification. After the initial endodontic microsurgery, all participants served as their own controls by performing another procedure with or without virtual pre-surgical practice. All procedures were videotaped and assessed by two independent observers using an endodontic competency rating scale (from 6 to 30). A significant difference was observed between the scores for endodontic microsurgery on molar teeth completed with virtual pre-surgical practice and those completed without virtual presurgical practice, median 24.5 (range = 17-28) versus median 18.75 (range = 14-26.5), P = 0.041. A significant difference was observed between the scores for osteotomy on a molar tooth completed with virtual pre-surgical practice and those completed without virtual pre-surgical practice, median 4.5 (range = 3.5-4.5) versus median 3 (range = 2-4), P = 0.042. Pre-surgical practice in a virtual environment using the 3D computerized model generated from the original CBCT image data improved endodontic microsurgery performance. © 2012 International Endodontic Journal.

  19. Recurrent surgical site infection of the spine diagnosed by dual 18F-NaF-bone PET/CT with early-phase scan

    International Nuclear Information System (INIS)

    Shim, Jai-Joon; Lee, Jeong Won; Jeon, Min Hyok; Lee, Sang Mi


    We report a case of a 31-year-old man who showed recurrently elevated level of the serum inflammatory marker C-reactive protein (CRP) after spinal operation. He underwent 18 F-flurodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) and dual 18 F-sodium-fluoride ( 18 F-NaF) PET/CT with an additional early-phase scan to find a hidden inflammation focus. Only mildly increased 18 F-FDG was found at the surgical site of T11 spine on 18 F-FDG PET/CT. In contrast, dual 18 F-NaF bone PET/CT with early-phase scan demonstrated focal active inflammation at the surgical site of T11 spine. After a revision operation of the T11 spine, serum CRP level decreased to the normal range without any symptom or sign of inflammation. Inflammatory focus in the surgical site of the spine can be detected with using dual 18 F-NaF bone PET/CT scan with early-phase scan. (orig.)

  20. Validating a Methodology for Establishing a Criteria and Proficiency Levels in Surgical Skills Simulators

    National Research Council Canada - National Science Library

    Heinrichs, LeRoy; Lukoff, Brian; Youngblood, Patricia; Dev, Parvati; Shavelson, Richard


    .... To establish training criteria, we have assessed the performance of 18 experienced laparoscopic surgeons basic technical surgical skills of recorded electronically in 26 basic skills modules selected...

  1. Balancing spinal stability and future mobility in the cervical spine: surgical treatment of a case of osteoblastoma with secondary aneurysmal bone cyst. (United States)

    Ramme, Austin J; Smucker, Joseph D


    The combination of osteoblastoma and aneurysmal bone cyst (ABC) in the cervical spine is a relatively rare occurrence in the general population. The diagnosis and surgical management of osteoblastoma and ABCs have been previously described in a small number of case reports/series and orthopedic texts. Lesions of the cervical spine pose challenges to surgeons that require preoperative planning and intraoperative decisions to ensure an appropriate patient outcome. Complete resection has been shown to be the most effective method for preventing recurrence; however, balancing spinal stability, future mobility, and complete resection is especially important in active young patients. We describe a modern approach to the surgical management of osteoblastoma with secondary ABC of the cervical spine with 4-year clinical and radiographic follow-up. Included in this report is a comprehensive review of the literature related to osteoblastoma, ABCs, and surgical issues pertinent to them. An independent retrospective case review combined with a review of current literature was performed. A single patient with a combination of osteoblastoma and secondary ABC is presented. During 4 years of follow-up, the patient has been evaluated with plain radiographs for subluxation or rotation of the cervical spine. Postoperative assessments for pain and range of motion were also collected. The medical, pathologic, and radiographic records of a case of osteoblastoma with secondary aneursymal bone cyst of the cervical spine were reviewed. A computer-based literature search of the PubMed database was used to compile a comprehensive review of the topic. The diagnosis and surgical treatment of osteoblastoma with secondary ABC in the cervical spine are discussed in the context of a literature review. The surgical management of this lesion was dictated by the size and location of the mass as well as the impact of the surgical resection on surrounding structures in terms of spinal stability and

  2. Implementation of simulation in surgical practice: minimally invasive surgery has taken the lead: the Dutch experience

    NARCIS (Netherlands)

    Schreuder, Henk W. R.; Oei, Guid; Maas, Mario; Borleffs, Jan C. C.; Schijven, Marlies P.


    Minimal invasive techniques are rapidly becoming standard surgical techniques for many surgical procedures. To develop the skills necessary to apply these techniques, box trainers and/or inanimate models may be used, but these trainers lack the possibility of inherent objective classification of

  3. Implementation of simulation in surgical practice : Minimally invasive surgery has taken the lead: The Dutch experience

    NARCIS (Netherlands)

    Schreuder, Henk W. R.; Oei, Guid; Maas, Mario; Borleffs, Jan C. C.; Schijven, Marlies P.


    Minimal invasive techniques are rapidly becoming standard surgical techniques for many surgical procedures. To develop the skills necessary to apply these techniques, box trainers and/or inanimate models may be used, but these trainers lack the possibility of inherent objective classification of

  4. Crestal Bone Loss under Delayed Loading of Full Thickness Versus Flapless Surgically Placed Dental Implants in Controlled Type 2 Diabetic Patients: A Parallel Group Randomized Clinical Trial. (United States)

    Yadav, Rohit; Agrawal, Kaushal Kishor; Rao, Jitendra; Anwar, Mohd; Alvi, Habib Ahmed; Singh, Kalpana; Himanshu, D


    controlled type 2 diabetic patients, levels of crestal bone loss around dental implants placed following conventional full thickness flap surgery was comparable to crestal bone loss around dental implants placed with the flapless surgical technique. More clinical studies are required regarding controlled type 2 diabetics with larger sample sizes, for long time periods to obtain more predictable results. © 2016 by the American College of Prosthodontists.

  5. Vascularized bone grafting in a canine carpal avascular necrosis model

    NARCIS (Netherlands)

    Willems, Wouter F.; Alberton, Gregory M.; Bishop, Allen T.; Kremer, Thomas


    Limited experimental research has been performed on the treatment of avascular necrosis (AVN) by vascularized bone grafting. A new model simulating carpal AVN was created to investigate surgical revascularization of necrotic bone. In seven mongrel dogs, AVN was induced by removal of the radial

  6. All Internal Segmental Bone Transport and Optional Lengthening With a Newly Developed Universal Cylinder-Kombi-Tube Module for Motorized Nails-Description of a Surgical Technique. (United States)

    Krettek, Christian; El Naga, Ashraf


    Segmental transport is an effective method of treatment for segmental defects, but the need for external fixation during the transport phase is a disadvantage. To avoid external fixation, we have developed a Cylinder-Kombi-Tube Segmental Transport (CKTST) module for combination with a commercially available motorized lengthening nail. This CKTST module allows for an all-internal segmental bone transport and also allows for optional lengthening if needed. The concept and surgical technique of CKTST are described and illustrated with a clinical case.

  7. Development and Assessment of a 3D-Printed Scaffold with rhBMP-2 for an Implant Surgical Guide Stent and Bone Graft Material: A Pilot Animal Study

    Directory of Open Access Journals (Sweden)

    Ji Cheol Bae


    Full Text Available In this study, a new concept of a 3D-printed scaffold was introduced for the accurate placement of an implant and the application of a recombinant human bone morphogenetic protein-2 (rhBMP-2-loaded bone graft. This preliminary study was conducted using two adult beagles to evaluate the 3D-printed polycaprolactone (PCL/β-tricalcium phosphate (β-TCP/bone decellularized extracellular matrix (bdECM scaffold conjugated with rhBMP-2 for the simultaneous use as an implant surgical guide stent and bone graft material that promotes new bone growth. Teeth were extracted from the mandible of the beagle model and scanned by computed tomography (CT to fabricate a customized scaffold that would fit the bone defect. After positioning the implant guide scaffold, the implant was placed and rhBMP-2 was injected into the scaffold of the experimental group. The two beagles were sacrificed after three months. The specimen block was obtained and scanned by micro-CT. Histological analysis showed that the control and experimental groups had similar new bone volume (NBV, % but the experimental group with BMP exhibited a significantly higher bone-to-implant contact ratio (BIC, %. Within the limitations of this preliminary study, a 3D-printed scaffold conjugated with rhBMP-2 can be used simultaneously as an implant surgical guide and a bone graft in a large bone defect site. Further large-scale studies will be needed to confirm these results.

  8. Development and Assessment of a 3D-Printed Scaffold with rhBMP-2 for an Implant Surgical Guide Stent and Bone Graft Material: A Pilot Animal Study (United States)

    Bae, Ji Cheol; Lee, Jin-Ju; Shim, Jin-Hyung; Park, Keun-Ho; Lee, Jeong-Seok; Bae, Eun-Bin; Choi, Jae-Won; Huh, Jung-Bo


    In this study, a new concept of a 3D-printed scaffold was introduced for the accurate placement of an implant and the application of a recombinant human bone morphogenetic protein-2 (rhBMP-2)-loaded bone graft. This preliminary study was conducted using two adult beagles to evaluate the 3D-printed polycaprolactone (PCL)/β-tricalcium phosphate (β-TCP)/bone decellularized extracellular matrix (bdECM) scaffold conjugated with rhBMP-2 for the simultaneous use as an implant surgical guide stent and bone graft material that promotes new bone growth. Teeth were extracted from the mandible of the beagle model and scanned by computed tomography (CT) to fabricate a customized scaffold that would fit the bone defect. After positioning the implant guide scaffold, the implant was placed and rhBMP-2 was injected into the scaffold of the experimental group. The two beagles were sacrificed after three months. The specimen block was obtained and scanned by micro-CT. Histological analysis showed that the control and experimental groups had similar new bone volume (NBV, %) but the experimental group with BMP exhibited a significantly higher bone-to-implant contact ratio (BIC, %). Within the limitations of this preliminary study, a 3D-printed scaffold conjugated with rhBMP-2 can be used simultaneously as an implant surgical guide and a bone graft in a large bone defect site. Further large-scale studies will be needed to confirm these results. PMID:29258172

  9. Development of femoral bone fracture model simulating muscular contraction force by pneumatic rubber actuator. (United States)

    Sen, Shin; Ando, Takehiro; Kobayashi, Etsuko; Miyamoto, Hideaki; Ohashi, Satoru; Tanaka, Sakae; Joung, Sanghyun; Park, Il-Hyung; Sakuma, Ichiro


    In femoral fracture reduction, orthopedic surgeons must pull distal bone fragments with great traction force and return them to their correct positions, by referring to 2D-fluoroscopic images. Since this method is physically burdensome, the introduction of robotic assistance is desirable. While such robots have been developed, adequate control methods have not yet been established because of the lack of experimental data. It is difficult to obtain accurate data using cadavers or animals because they are different from the living human body's muscle characteristics and anatomy. Therefore, an experimental model for simulating human femoral characteristics is required. In this research, human muscles are reproduced using a McKibben-type pneumatic rubber actuator (artificial muscle) to develop a model that simulates typical femur muscles using artificial muscles.

  10. Can teenage novel users perform as well as General Surgery residents upon initial exposure to a robotic surgical system simulator? (United States)

    Mehta, A; Patel, S; Robison, W; Senkowski, T; Allen, J; Shaw, E; Senkowski, C


    New techniques in minimally invasive and robotic surgical platforms require staged curricula to insure proficiency. Scant literature exists as to how much simulation should play a role in training those who have skills in advanced surgical technology. The abilities of novel users may help discriminate if surgically experienced users should start at a higher simulation level or if the tasks are too rudimentary. The study's purpose is to explore the ability of General Surgery residents to gain proficiency on the dVSS as compared to novel users. The hypothesis is that Surgery residents will have increased proficiency in skills acquisition as compared to naive users. Six General Surgery residents at a single institution were compared with six teenagers using metrics measured by the dVSS. Participants were given two 1-h sessions to achieve an MScoreTM in the 90th percentile on each of the five simulations. MScoreTM software compiles a variety of metrics including total time, number of attempts, and high score. Statistical analysis was run using Student's t test. Significance was set at p value <0.05. Total time, attempts, and high score were compared between the two groups. The General Surgery residents took significantly less Total Time to complete Pegboard 1 (PB1) (p = 0.043). No significant difference was evident between the two groups in the other four simulations across the same MScoreTM metrics. A focused look at the energy dissection task revealed that overall score might not be discriminant enough. Our findings indicate that prior medical knowledge or surgical experience does not significantly impact one's ability to acquire new skills on the dVSS. It is recommended that residency-training programs begin to include exposure to robotic technology.

  11. [Simulation of dose distribution in bone medium of125I photon emitting source with Monte Carlo method]. (United States)

    Ye, K Q; Huang, M W; Li, J L; Tang, J T; Zhang, J G


    To present a theoretical analysis of how the presence of bone in interstitial brachytherapy affects dose rate distributions with MCNP4C Monte Carlo code and to prepare for the next clinical study on the dose distribution of interstitial brachytherapy in head and neck neoplasm. Type 6711, 125 I brachytherapy source was simulated with MCNP4C Monte Carlo code whose cross section library was DLC-200. The dose distribution along the transverse axis in water and dose constant were compared with the American Association of Physicists in Medicine (AAPM) TG43UI update dosimetry formalism and current literature. The validated computer code was then applied to simple homogeneous bone tissue model to determine the affected different bone tissue had on dose distribution from 125 I interstitial implant. 125 I brachytherapy source simulated with MCNP4C Monte Carlo code met the requirements of TG43UI report. Dose rate constant, 0.977 78 cGy/(h×U), was in agreement within 1.32% compared with the recommended value of TG43UI. There was a good agreement between TG43UI about the dosimetric parameters at distances of 1 to 10 cm along the transverse axis of the 125 I source established by MCNP4C and current published data. And the dose distribution of 125 I photon emitting source in different bone tissue was calculated. Dose-deposition capacity of photons was in decreasing order: cortical bone, spongy bone, cartilage, yellow bone marrow, red bone marrow in the same medium depth. Photons deposited significantly in traversal axis among the phantom material of cortical bone and sponge bone relevant to the dose to water. In the medium depth of 0.01 cm, 0.1 cm, and 1 cm, the dose in the cortical bone was 12.90 times, 9.72 times, and 0.30 times of water respectively. This study build a 125 I source model with MCNP4C Monte Carlo code, which is validated, and could be used in subsequent study. Dose distribution of photons in different bone medium is not the same as water, and its main energy

  12. Simulation-based cutaneous surgical-skill training on a chicken-skin bench model in a medical undergraduate program

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    Rafael Denadai


    Full Text Available Background: Because of ethical and medico-legal aspects involved in the training of cutaneous surgical skills on living patients, human cadavers and living animals, it is necessary the search for alternative and effective forms of training simulation. Aims: To propose and describe an alternative methodology for teaching and learning the principles of cutaneous surgery in a medical undergraduate program by using a chicken-skin bench model. Materials and Methods: One instructor for every four students, teaching materials on cutaneous surgical skills, chicken trunks, wings, or thighs, a rigid platform support, needled threads, needle holders, surgical blades with scalpel handles, rat-tooth tweezers, scissors, and marking pens were necessary for training simulation. Results: A proposal for simulation-based training on incision, suture, biopsy, and on reconstruction techniques using a chicken-skin bench model distributed in several sessions and with increasing levels of difficultywas structured. Both feedback and objective evaluations always directed to individual students were also outlined. Conclusion: The teaching of a methodology for the principles of cutaneous surgery using a chicken-skin bench model versatile, portable, easy to assemble, and inexpensive is an alternative and complementary option to the armamentarium of methods based on other bench models described.

  13. The impact of critical event checklists on medical management and teamwork during simulated crises in a surgical daycare facility. (United States)

    Everett, T C; Morgan, P J; Brydges, R; Kurrek, M; Tregunno, D; Cunningham, L; Chan, A; Forde, D; Tarshis, J


    Although the incidence of major adverse events in surgical daycare centres is low, these critical events may not be managed optimally due to the absence of resources that exist in larger hospitals. We aimed to study the impact of operating theatre critical event checklists on medical management and teamwork during whole-team operating theatre crisis simulations staged in a surgical daycare facility. We studied 56 simulation encounters (without and with a checklist available) divided between an initial session and then a retention session several months later. Medical management and teamwork were quantified via percentage adherence to key processes and the Team Emergency Assessment Measure, respectively. In the initial session, medical management was not improved by the presence of a checklist (56% without checklist vs. 62% with checklist; p = 0.50). In the retention session, teams performed significantly worse without the checklists (36% without checklist vs. 60% with checklist; p = 0.04). We did not observe a change in non-technical skills in the presence of a checklist in either the initial or retention sessions (68% without checklist vs. 69% with checklist (p = 0.94) and 69% without checklist vs. 65% with checklist (p = 0.36), respectively). Critical events checklists do not improve medical management or teamwork during simulated operating theatre crises in an ambulatory surgical daycare setting. © 2016 The Association of Anaesthetists of Great Britain and Ireland.

  14. Autologous bone marrow mononuclear cell transplant and surgical decompression in a dog with chronic spinal cord injury. (United States)

    Tamura, Katsutoshi; Harada, Yasuji; Kunimi, Maki; Takemitsu, Hiroshi; Hara, Yasushi; Nakamura, Tatsuo; Tagawa, Masahiro


    In dogs with deep analgesia caused by acute spinal cord injury from thoracolumbar disk herniation, autologous bone marrow mononuclear cell transplant may improve recovery. The purpose of the present study was to evaluate autologous bone marrow mononuclear cell transplant in a dog that had paraplegia and deep analgesia caused by chronic spinal cord injury. Autologous bone marrow mononuclear cell transplant was performed in a dog having paraplegia and analgesia for 3 years that was caused by a chronic spinal cord injury secondary to Hansen type I thoracolumbar disk herniation. Functional recovery was evaluated with electrophysiologic studies and the Texas Spinal Cord Injury Scale. Somatosensory evoked potentials were absent before transplant but were detected after transplant. Functional improvement was noted (Texas Spinal Cord Injury Scale: before transplant, 0; after transplant, 6). No adverse events were observed. Autologous bone marrow mononuclear cell transplant into the subarachnoid space may be a safe and beneficial treatment for chronic spinal cord injury in dogs.

  15. Introducing the Xitact LS500 laparoscopy simulator: toward a revolution in surgical education

    NARCIS (Netherlands)

    Schijven, Marlies P.; Jakimowicz, Jack J.


    Minimal invasive surgery has become the primary technique-of-choice for uncomplicated, symptomatic cholelithiasis. Skills needed for performing laparoscopic cholecystectomy cannot be extrapolated directly from the open surgical technique. An obvious need exists for a valid, objective, and repetitive

  16. Influence of simulated bone-implant contact and implant diameter on secondary stability: a resonance frequency in vitro study. (United States)

    Veltri, Mario; González-Martín, Oscar; Belser, Urs C


    This study tested the hypothesis of no differences in resonance frequency for standardized amounts of simulated bone-implant contact around implants with different diameters. In addition, it was evaluated if resonance frequency is able to detect a difference between stable and rotation mobile ("spinning") implants. Implants with diameters of 3.3, 4.1 and 4.8 mm were placed in a purposely designed metal mould where liquid polyurethane resin was then poured to obtain a simulated bone-implant specimen. By regulating the mould, it was possible to create the following simulated bone-implant contact groups: 3.3 mm (198.6 mm(2)); 4.1 mm (198.8 mm(2)); 4.8 mm (200.2 mm(2)); 4.8 mm (231.7 mm(2)); 4.8 mm (294.7 mm(2)). Each group included 10 specimens. After resin setting, resonance frequency was measured. On the last group, measurements were repeated after establishing implant rotational mobility. One-way ANOVA tests with post hoc comparisons, a Pearson's correlation coefficient and a t-test for repeated measurements were used to evaluate statistically significant differences. Implants with different diameters but with the same amount of simulated osseointegration revealed no differences in resonance frequency. On the contrary, an increase of simulated bone-implant contact resulted in significantly higher resonance frequency. A clear direct linear correlation resulted between resonance frequency and simulated bone-implant contact. Furthermore, a significant difference resulted between resonance frequency measured before and after creation of rotational mobility. Within the conditions of this study, the secondary stability was correlated with the simulated bone-implant contact. In addition, resonance frequency was able to discern between stable and rotation mobile implants. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Impact of surgical management in cases of intraoperative membrane perforation during a sinus lift procedure: a follow-up on bone graft stability and implant success. (United States)

    Beck-Broichsitter, Benedicta E; Westhoff, Dorothea; Behrens, Eleonore; Wiltfang, Jörg; Becker, Stephan T


    Until now, sinus floor elevation represents the gold standard procedure in the atrophic maxilla in order to facilitate dental implant insertion. Although the procedure remains highly predictive, the perforation of the Schneiderian membrane might compromise the stability of the augmented bone and implant success due to chronic sinus infection. The aim of this retrospective cohort study was to show that a membrane tear, if detected and surgically properly addressed, has no influence on the survival of dental implants and bone resorption in the augmented area. Thirty-one patients with 39 perforations could be included in this evaluation, and a control group of 32 patients with 40 sinus lift procedures without complications were compared regarding the radiographically determined development of bone level, peri-implant infection, and implant loss. Implant survival was 98.9% in the perforation group over an observation period of 2.7 (± 2.03) years compared to 100% in the control group after 1.8 (± 1.57) years. The residual bone level was significantly lower in the perforation group (p = 0.05) but showed no difference direct postoperatively (p = 0.7851) or in the follow-up assessment (p = 0.2338). Bone resorption remained not different between both groups (p = 0.945). A two-stage procedure was more frequent in the perforation group (p = 0.0003) as well as peri-implantitis (p = 0.0004). Within the limits of our study, the perforation of the Schneiderian membrane did not have a negative impact on long-term graft stability or the overall implant survival.


    Au Yong, Jo Anne; Lewis, Daniel D; Citino, Scott B; Cunningham, Mark W; Cross, Alan R; Farese, James P; Pablo, Luisito S


    The clinical outcomes of six free-ranging Florida panthers ( Puma concolor coryi) that underwent surgical stabilization of appendicular long-bone fractures (three femoral fractures, one tibial and one tibial and fibular fracture and two radial and ulnar fractures) were evaluated. These panthers presented to the University of Florida from 2000-2014. Estimated age of the panthers ranged from 0.5 to 4.5 yr, and weights ranged from 22 to 65 kg. Causes of injuries were vehicular collision ( n = 4) and capture related ( n = 2). All panthers underwent open reduction and fracture stabilization. Fixation failure necessitated three subsequent surgeries in one panther. Five panthers survived the immediate postoperative period, and all of these panthers' fractures obtained radiographic union (range, 8-36 [mean, 22] wk). The five surviving panthers underwent convalescence for 7-14 mo at White Oak Conservation Center before being released back into the wild; however, one panther was killed when hit by a car 3 days after release. The remaining four panthers were tracked for up to 106 mo in the wild and successfully integrated back into the native population. Surgical stabilization of appendicular long-bone fractures in free-ranging Florida panthers can be successful, but must take into account the stress that a large, undomesticated felid will place on the stabilized limb during convalescence as well as the difficulties involved in rehabilitating a wild panther in captivity.

  19. Outcomes of a virtual-reality simulator-training programme on basic surgical skills in robot-assisted laparoscopic surgery. (United States)

    Phé, Véronique; Cattarino, Susanna; Parra, Jérôme; Bitker, Marc-Olivier; Ambrogi, Vanina; Vaessen, Christophe; Rouprêt, Morgan


    The utility of the virtual-reality robotic simulator in training programmes has not been clearly evaluated. Our aim was to evaluate the impact of a virtual-reality robotic simulator-training programme on basic surgical skills. A simulator-training programme in robotic surgery, using the da Vinci Skills Simulator, was evaluated in a population including junior and seasoned surgeons, and non-physicians. Their performances on robotic dots and suturing-skin pod platforms before and after virtual-simulation training were rated anonymously by surgeons experienced in robotics. 39 participants were enrolled: 14 medical students and residents in surgery, 14 seasoned surgeons, 11 non-physicians. Junior and seasoned surgeons' performances on platforms were not significantly improved after virtual-reality robotic simulation in any of the skill domains, in contrast to non-physicians. The benefits of virtual-reality simulator training on several tasks to basic skills in robotic surgery were not obvious among surgeons in our initial and early experience with the simulator. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  20. Drilling simulated temporal bones with left-handed tools: a left-hander's right? (United States)

    Torgerson, Cory S; Brydges, Ryan; Chen, Joseph M; Dubrowski, Adam


    Left-handed trainees can be at a disadvantage in the surgical environment because of a right-handed bias. The effectiveness of teaching left-handed trainees to use an otologic drill designed for their dominant hand versus the conventional right-handed drill was examined. Novice medical students were recruited from the university community. Twenty-four subjects were left-handed, and 12 were right-handed. Eight left-handed surgeons also participated. A randomized controlled trial was conducted to compare the performance of left-handed trainees using novel left-handed drills to that of left-handed trainees using right-handed tools and to that of right-handed trainees using right-handed tools. The evaluation consisted of 3 phases: pretest, skill acquisition, and 2 post-tests. The measurement tools included expert assessment of performance, and subjective and objective final product analyses. An initial construct validity phase was conducted in which validity of the assessment tools was ensured. Both the left-handers using left-handed tools and the right-handers using right-handed tools significantly outperformed the left-handers using right-handed tools at pretest, immediate posttest, and delayed posttest. All participants improved their performance as a function of practice. The left-handed trainees learned bone drilling better with tools designed for the left hand. These tools may be incorporated into residency training programs for the development of surgical technical skills. Future studies should assess skill transfer between the left-handed and right-handed drills.

  1. Simulated surgical workshops enhance medical school students’ preparation for clinical rotation

    Directory of Open Access Journals (Sweden)

    Patricia Johnson


    Full Text Available BackgroundA major focus of the medical school curriculum is to ensure medical students are well prepared prior to entering clinical rotations, which includes the compulsory surgical rotation.AimsThe objective of this research was to design and formally evaluate a set of real-life surgical workshops aimed at better preparing medical students for their clinical rotation in surgery. These workshops would be incorporated into the pre-clinical medical school curriculum.MethodDedicated surgical workshops were introduced into the preclinical component of the Bachelor of Medicine/Bachelor of Surgery (MBBS program at our University in 2009. These workshops encompassed training in the clinical skills needed in the perioperative and wider hospital setting. A survey comprising of eight to nine ranked questions (utilising a five-point Likert Scale as well as three short answer questions was administered to the medical students after they completed their compulsory surgical clinical rotation.ResultsThe overall response rate to the survey evaluating the surgical workshops was 79% (123/155. The mean of the ranked questions ranged from 4.05 to 4.89 which indicated that the students found the workshops useful. When evaluating the short answer questions (via topic coding, additional information was provided that supported and explained the survey findings and also included suggestions for improvements.ConclusionThe findings of the medical student survey demonstrated the value of incorporating dedicated preparatory surgical workshops in the medical school pre-clinical curriculum. However, further research is warranted to determine if this inclusion translated into improved student performance during the clinical surgical rotation.

  2. Development and validation of a laparoscopic hysterectomy cuff closure simulation model for surgical training. (United States)

    Tunitsky-Bitton, Elena; Propst, Katie; Muffly, Tyler


    The number of robotically assisted hysterectomies is increasing, and therefore, the opportunities for trainees to become competent in performing traditional laparoscopic hysterectomy are decreasing. Simulation-based training is ideal for filling this gap in training. The objective of the study was to design a surgical model for training in laparoscopic vaginal cuff closure and to present evidence of its validity and reliability as an assessment and training tool. Participants included gynecology staff and trainees at 2 tertiary care centers. Experienced surgeons were also recruited at the combined International Urogynecologic Association and American Urogynecologic Society scientific meeting. Participants included 19 experts and 21 trainees. All participants were recorded using the laparoscopic hysterectomy cuff closure simulation model. The model was constructed using the an advanced uterine manipulation system with a sacrocolopexy tip/vaginal stent, a vaginal cuff constructed from neoprene material and lined with a swimsuit material (nylon and spandex) secured to the vaginal stent with a plastic cable tie. The uterine manipulation system was attached to the fundamentals of laparoscopic surgery laparoscopic training box trainer using a metal bracket. Performance was evaluated using the Global Operative Assessment of Laparoscopic Skills scale. In addition, needle handling, knot tying, and incorporation of epithelial edge were also evaluated. The Student t test was used to compare the scores and the operating times between the groups. Intrarater reliability between the scores by the 2 masked experts was measured using the interclass correlation coefficient. Total and annual experience with laparoscopic suturing and specifically vaginal cuff closure varied greatly among the participants. For the construct validity, the participants in the expert group received significantly higher scores in each of the domains of the Global Operative Assessment of Laparoscopic Skills

  3. Adding tactile realism to a virtual reality laparoscopic surgical simulator with a cost-effective human interface device (United States)

    Mack, Ian W.; Potts, Stephen; McMenemy, Karen R.; Ferguson, R. S.


    The laparoscopic technique for performing abdominal surgery requires a very high degree of skill in the medical practitioner. Much interest has been focused on using computer graphics to provide simulators for training surgeons. Unfortunately, these tend to be complex and have a very high cost, which limits availability and restricts the length of time over which individuals can practice their skills. With computer game technology able to provide the graphics required for a surgical simulator, the cost does not have to be high. However, graphics alone cannot serve as a training simulator. Human interface hardware, the equivalent of the force feedback joystick for a flight simulator game, is required to complete the system. This paper presents a design for a very low cost device to address this vital issue. The design encompasses: the mechanical construction, the electronic interfaces and the software protocols to mimic a laparoscopic surgical set-up. Thus the surgeon has the capability of practicing two-handed procedures with the possibility of force feedback. The force feedback and collision detection algorithms allow surgeons to practice realistic operating theatre procedures with a good degree of authenticity.

  4. Estimation of anisotropic permeability in trabecular bone based on microCT imaging and pore-scale fluid dynamics simulations. (United States)

    Daish, C; Blanchard, R; Gulati, K; Losic, D; Findlay, D; Harvie, D J E; Pivonka, P


    In this paper, a comprehensive framework is proposed to estimate the anisotropic permeability matrix in trabecular bone specimens based on micro-computed tomography (microCT) imaging combined with pore-scale fluid dynamics simulations. Two essential steps in the proposed methodology are the selection of (i) a representative volume element (RVE) for calculation of trabecular bone permeability and (ii) a converged mesh for accurate calculation of pore fluid flow properties. Accurate estimates of trabecular bone porosities are obtained using a microCT image resolution of approximately 10 μm. We show that a trabecular bone RVE in the order of 2 × 2 × 2 mm 3 is most suitable. Mesh convergence studies show that accurate fluid flow properties are obtained for a mesh size above 125,000 elements. Volume averaging of the pore-scale fluid flow properties allows calculation of the apparent permeability matrix of trabecular bone specimens. For the four specimens chosen, our numerical results show that the so obtained permeability coefficients are in excellent agreement with previously reported experimental data for both human and bovine trabecular bone samples. We also identified that bone samples taken from long bones generally exhibit a larger permeability in the longitudinal direction. The fact that all coefficients of the permeability matrix were different from zero indicates that bone samples are generally not harvested in the principal flow directions. The full permeability matrix was diagonalized by calculating the eigenvalues, while the eigenvectors showed how strongly the bone sample's orientations deviated from the principal flow directions. Porosity values of the four bone specimens range from 0.83 to 0.86, with a low standard deviation of ± 0.016, principal permeability values range from 0.22 to 1.45 ⋅ 10  -8  m 2 , with a high standard deviation of ± 0.33. Also, the anisotropic ratio ranged from 0.27 to 0.83, with high standard deviation. These

  5. Aesthetic Surgical Approach for Bone Dehiscence Treatment by Means of Single Implant and Interdental Tissue Regeneration: A Case Report with Five Years of Follow-Up

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    Giorgio Lombardo


    Full Text Available The replacement of single anterior teeth by means of endosseous implants implies the achievement of success in restoring both aesthetic and function. However, the presence of wide endoperiodontal lesions can lead to horizontal hard and soft tissues defects after tooth extraction, making it impossible to correctly place an implant in the compromised alveolar socket. Vertical augmentation procedures have been proposed to solve these clinical situations, but the amount of new regenerated bone is still not predictable. Furthermore, bone augmentation can be complicated by the presence of adjacent teeth, especially if they bring with them periodontal defects. Therefore, it is used to restore periodontal health of adjacent teeth before making any augmentation procedures and to wait a certain healing period before placing an implant in vertically augmented sites, otherwise risking to obtain a nonsatisfactory aesthetic result. All of these procedures, however, lead to an expansion of treatment time which should affect patient compliance. For this reason, this case report suggests a surgical technique to perform vertical bone augmentation at a single gap left by a central upper incisor while placing an implant and simultaneously to regenerate the periodontal attachment of an adjacent lateral incisor, without compromising the aesthetic result.

  6. Aesthetic Surgical Approach for Bone Dehiscence Treatment by Means of Single Implant and Interdental Tissue Regeneration: A Case Report with Five Years of Follow-Up (United States)

    Lombardo, Giorgio; Pighi, Jacopo; Corrocher, Giovanni; Mascellaro, Anna; Lehrberg, Jeffrey; Marincola, Mauro; Nocini, Pier Francesco


    The replacement of single anterior teeth by means of endosseous implants implies the achievement of success in restoring both aesthetic and function. However, the presence of wide endoperiodontal lesions can lead to horizontal hard and soft tissues defects after tooth extraction, making it impossible to correctly place an implant in the compromised alveolar socket. Vertical augmentation procedures have been proposed to solve these clinical situations, but the amount of new regenerated bone is still not predictable. Furthermore, bone augmentation can be complicated by the presence of adjacent teeth, especially if they bring with them periodontal defects. Therefore, it is used to restore periodontal health of adjacent teeth before making any augmentation procedures and to wait a certain healing period before placing an implant in vertically augmented sites, otherwise risking to obtain a nonsatisfactory aesthetic result. All of these procedures, however, lead to an expansion of treatment time which should affect patient compliance. For this reason, this case report suggests a surgical technique to perform vertical bone augmentation at a single gap left by a central upper incisor while placing an implant and simultaneously to regenerate the periodontal attachment of an adjacent lateral incisor, without compromising the aesthetic result. PMID:27119031

  7. A serious game skills competition increases voluntary usage and proficiency of a virtual reality laparoscopic simulator during first-year surgical residents' simulation curriculum. (United States)

    El-Beheiry, Mostafa; McCreery, Greig; Schlachta, Christopher M


    The objective of this study was to assess the effect of a serious game skills competition on voluntary usage of a laparoscopic simulator among first-year surgical residents' standard simulation curriculum. With research ethics board approval, informed consent was obtained from first-year surgical residents enrolled in an introductory surgical simulation curriculum. The class of 2013 served as a control cohort following the standard curriculum which mandates completion of six laparoscopic simulator skill tasks. For the 2014 competition cohort, the only change introduced was the biweekly and monthly posting of a leader board of the top three and ten fastest peg transfer times. Entry surveys were administered assessing attitudes towards simulation-based training and competition. Cohorts were observed for 5 months. There were 24 and 25 residents in the control and competition cohorts, respectively. The competition cohort overwhelmingly (76 %) stated that they were not motivated to deliberate practice by competition. Median total simulator usage time was 132 min (IQR = 214) in the competition cohort compared to 89 (IQR = 170) in the control cohort. The competition cohort completed their course requirements significantly earlier than the control cohort (χ 2  = 6.5, p = 0.01). There was a significantly greater proportion of residents continuing to use the simulator voluntarily after completing their course requirements in the competition cohort (44 vs. 4 %; p = 0.002). Residents in the competition cohort were significantly faster at peg transfer (194 ± 66 vs. 233 ± 53 s, 95 % CI of difference = 4-74 s; p = 0.03) and significantly decreased their completion time by 33 ± 54 s (95 % CI 10-56 s; paired t test, p = 0.007). A simple serious games skills competition increased voluntary usage and performance on a laparoscopic simulator, despite a majority of participants reporting they were not motivated by competition. Future directions should

  8. Surgery-first approach using a three-dimensional virtual setup and surgical simulation for skeletal Class III correction. (United States)

    Im, Joon; Kang, Sang Hoon; Lee, Ji Yeon; Kim, Moon Key; Kim, Jung Hoon


    A 19-year-old woman presented to our dental clinic with anterior crossbite and mandibular prognathism. She had a concave profile, long face, and Angle Class III molar relationship. She showed disharmony in the crowding of the maxillomandibular dentition and midline deviation. The diagnosis and treatment plan were established by a three-dimensional (3D) virtual setup and 3D surgical simulation, and a surgical wafer was produced using the stereolithography technique. No presurgical orthodontic treatment was performed. Using the surgery-first approach, Le Fort I maxillary osteotomy and mandibular bilateral intraoral vertical ramus osteotomy setback were carried out. Treatment was completed with postorthodontic treatment. Thus, symmetrical and balanced facial soft tissue and facial form as well as stabilized and well-balanced occlusion were achieved.

  9. The virtual reality simulator dV-Trainer(®) is a valid assessment tool for robotic surgical skills. (United States)

    Perrenot, Cyril; Perez, Manuela; Tran, Nguyen; Jehl, Jean-Philippe; Felblinger, Jacques; Bresler, Laurent; Hubert, Jacques


    Exponential development of minimally invasive techniques, such as robotic-assisted devices, raises the question of how to assess robotic surgery skills. Early development of virtual simulators has provided efficient tools for laparoscopic skills certification based on objective scoring, high availability, and lower cost. However, similar evaluation is lacking for robotic training. The purpose of this study was to assess several criteria, such as reliability, face, content, construct, and concurrent validity of a new virtual robotic surgery simulator. This prospective study was conducted from December 2009 to April 2010 using three simulators dV-Trainers(®) (MIMIC Technologies(®)) and one Da Vinci S(®) (Intuitive Surgical(®)). Seventy-five subjects, divided into five groups according to their initial surgical training, were evaluated based on five representative exercises of robotic specific skills: 3D perception, clutching, visual force feedback, EndoWrist(®) manipulation, and camera control. Analysis was extracted from (1) questionnaires (realism and interest), (2) automatically generated data from simulators, and (3) subjective scoring by two experts of depersonalized videos of similar exercises with robot. Face and content validity were generally considered high (77 %). Five levels of ability were clearly identified by the simulator (ANOVA; p = 0.0024). There was a strong correlation between automatic data from dV-Trainer and subjective evaluation with robot (r = 0.822). Reliability of scoring was high (r = 0.851). The most relevant criteria were time and economy of motion. The most relevant exercises were Pick and Place and Ring and Rail. The dV-Trainer(®) simulator proves to be a valid tool to assess basic skills of robotic surgery.

  10. WIse-2005: Combined Aerobic and Resistive Exercise May Help Mitigate Bone Loss During 60-D Simulated Microgravity in Women (United States)

    Smith, Scott M.; Zwart, S. R.; Heer, M. A.; Lee, S. M. C.; Macias, B. R.; Schneider, S. M.; Trappe, S. M.; Hargens, A. R.


    Exercise can attenuate bone loss associated with disuse during bed rest (BR), an analog of space flight. Previous studies have examined the efficacy of aerobic or resistive exercise countermeasures, but not in combination. We sought to determine the effect of a combined resistive and aerobic exercise regimen on bone metabolism during BR. After a 20-d ambulatory adaptation to confinement and diet, 16 women participated in a 60-d head-down-tilt BR. Control subjects (CN, n=8) performed no countermeasures. Exercise subjects, (EX, n=8) participated in exercise alternating daily between supine treadmill exercise within lower body negative pressure and resistive fly-wheel exercise (6-d wk(sup -1)). In the last week of BR, bone resorption was greater (p less than 79 plus or minus 44%, mean plus or minus SD) and EX groups (64 50%). N-telopeptide also increased (CN: 51 plus or minus 34%; EX: 43 plus or minus 56%). However, bone-specific alkaline phosphatase, a bone formation marker, tended to be higher in EX (26 plus or minus 18%) than in CN (8 plus or minus 33%) groups. The combination of resistive and aerobic exercise does not prevent bone resorption, but may promote formation, potentially mitigating the net bone loss associated with simulated microgravity. This study was supported by CNES, CSA, ESA, NASA, and NASA grant NNJ04HF71G to ARH. MEDES (French Institute for Space Medicine and Physiology) organized the study.

  11. Surgical management of diaphyseal humeral nonunion after intramedullary nailing: Wave-plate fixation and autologous bone grafting without nail removal

    NARCIS (Netherlands)

    Gerber, Ariane; Marti, René; Jupiter, Jesse


    Six patients with a nonunion of the humeral diaphysis after intramedullary nailing were treated with a wave plate and autologous bone graft but without removal of the intramedullary implant. The mean duration of the nonunion was 19 months (range, 6-36 months). At a mean follow-up of 12 months

  12. Femoral component revision with use of impaction bone-grafting and a cemented polished stem. Surgical technique.

    NARCIS (Netherlands)

    Schreurs, B.W.; Arts, J.J.C.; Verdonschot, N.J.J.; Buma, P.; Slooff, T.J.J.H.; Gardeniers, J.W.M.


    BACKGROUND: The purpose of this study was to evaluate the clinical and radiographic outcomes of revision of the femoral component of a hip arthroplasty with use of an impaction bone-grafting technique and a cemented polished stem. METHODS: Thirty-three consecutive femoral reconstructions that were

  13. Leaders by example: Best practices and advice on establishing a state-of-the art surgical simulation center that optimizes available resources. (United States)

    Gardner, A K; Ritter, E M; Dunkin, B J; Smink, D S; Lau, J N; Paige, J T; Phitayakorn, R; Acton, R D; Stefanidis, D; Gee, D W


    The role of simulation-based education continues to expand exponentially. To excel in this environment as a surgical simulation leader requires unique knowledge, skills, and abilities that are different from those used in traditional clinically-based education. Leaders in surgical simulation were invited to participate as discussants in a pre-conference course offered by the Association for Surgical Education. Highlights from their discussions were recorded. Recommendations were provided on topics such as building a simulation team, preparing for accreditation requirements, what to ask for during early stages of development, identifying tools and resources needed to meet educational goals, expanding surgical simulation programming, and building educational curricula. These recommendations provide new leaders in simulation with a unique combination of up-to-date best practices in simulation-based education, as well as valuable advice gained from lessons learned from the personal experiences of national leaders in the field of surgical simulation and education. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. [Press-fit bone dowel arthrodesis of the ankle or the subtalar joint using a diamond bone cutting system. Surgical technique and initial results in 10 patients]. (United States)

    Dresing, K; Stürmer, K M


    Arthrodesis of the ankle (AA) or the subtalar joint (AST) is still a necessary treatment in case of painful posttraumatic arthrosis or paresis of the muscles after compartment syndrome. Today the alloplastic ankle joint replacement does not satisfy. Many treatments of arthrodesis with minimal or extended resection of the joint surface with or without bone transplantation are described in literature. We present in detail a new developed technique of press-fit dowel arthrodesis (KDA) for the ankle and subtalar joint. After adjustment of the joint position and retention with Kirschner wires the surface of both sides of the joint surface and underlying bone is removed by a cannulated diamond bone cutting device. Dowels from the anterior iliac crest are impacted in the cutted joint defect. The dowels are 1/10 mm bigger in dimension than the primary defect in the joint surface. The surgery will be completed with a compression screw osteosynthesis, at the ankle joint transarticular through the lateral and medial malleolus, at the subtalar joint from plantar. Ten patients have treated by press-fit-KDA (female 2, male 8; AA 7, 33.6 +/- 9 y; AST 3.38 +/- 10.9 y). The indication for KDA was in nine cases a severe posttraumatic arthrosis, in one case the paretic malfunction after compartment syndrome. The arthrodesis were clinically and radiologically consolidated after 8.2 +/- 1.9 weeks. At this time the patients showed no symptoms and were fully mobilised with complete weight-bearing. The advantages of KDA: preservation of the outline of joint and hindfoot, preservation of length of the leg and outline of iliac crest, no risk for the soft tissue, quick consolidation of the arthrodesis, no need of external fixation. The technique is also suitable for other indications as presented.

  15. Surgical repair of propagating condylar fractures of the third metacarpal/metatarsal bones with cortical screws placed in lag fashion in 26 racehorses (2007-2015). (United States)

    Moulin, N; François, I; Coté, N; Alford, C; Cleary, O; Desjardins, M R


    Despite the recommendation of plate fixation for propagating condylar fractures of the third metacarpal (McIII) or third metatarsal bone (MtIII), lag screw fixation can be a viable surgical option. To evaluate short-term outcome and long-term racing performance of horses that underwent lag screw fixation of long condylar fractures of the McIII/MtIII. Retrospective case series. Medical records, post-surgical racing performance and outcome of 26 horses with propagating fractures of the medial and/or lateral condyle of McIII/MtIII were reviewed. Medical information included were age, breed, sex, physical examination at admission, circumstances of fracture, radiographic evaluation, anaesthesia and recovery records, surgical and post-operative management, as well as complications. Outcome included racing data and information from telephone interviews. Twenty-six horses (9 Standardbreds and 17 Thoroughbreds) were admitted with a long condylar fracture of the McIII/MtIII. Fore- and hindlimbs were equally represented with the left hindlimb being more frequently involved. Most of the fractures had a spiralling component (76%) and four (15%) were comminuted. Fifteen (58%) horses raced post-surgery including nine Standardbreds (100%) and six Thoroughbreds (35%). Twelve of them were placed in at least one race and 11 won at least once. One horse sustained a severe complication in recovery. No significant difference was observed in the racing performances before and after surgery. Follow-up method and duration were not standardised and there is a low number of cases with six surgeons. Long condylar fractures can be repaired using lag fashion technique combined with a half-limb or full-limb tight cast for recovery as a good surgical alternative. Similar results to plate fixation can be expected, with a return to racing of more than 50%, and the prognosis being even better for pacers. © 2018 EVJ Ltd.

  16. 3D Computer graphics simulation to obtain optimal surgical exposure during microvascular decompression of the glossopharyngeal nerve. (United States)

    Hiraishi, Tetsuya; Matsushima, Toshio; Kawashima, Masatou; Nakahara, Yukiko; Takahashi, Yuichi; Ito, Hiroshi; Oishi, Makoto; Fujii, Yukihiko


    The affected artery in glossopharyngeal neuralgia (GPN) is most often the posterior inferior cerebellar artery (PICA) from the caudal side or the anterior inferior cerebellar artery (AICA) from the rostral side. This technical report describes two representative cases of GPN, one with PICA as the affected artery and the other with AICA, and demonstrates the optimal approach for each affected artery. We used 3D computer graphics (3D CG) simulation to consider the ideal transposition of the affected artery in any position and approach. Subsequently, we performed microvascular decompression (MVD) surgery based on this simulation. For PICA, we used the transcondylar fossa approach in the lateral recumbent position, very close to the prone position, with the patient's head tilted anteriorly for caudal transposition of PICA. In contrast, for AICA, we adopted a lateral suboccipital approach with opening of the lateral cerebellomedullary fissure, to visualize better the root entry zone of the glossopharyngeal nerve and to obtain a wide working space in the cerebellomedullary cistern, for rostral transposition of AICA. Both procedures were performed successfully. The best surgical approach for MVD in patients with GPN is contingent on the affected artery--PICA or AICA. 3D CG simulation provides tailored approach for MVD of the glossopharyngeal nerve, thereby ensuring optimal surgical exposure.

  17. Evaluation of diabetic foot osteomyelitis using probe to bone test and magnetic resonance imaging and their impact on surgical intervention

    Directory of Open Access Journals (Sweden)

    Fatma Zaiton


    Conclusion: PTB test is a simple, minimally invasive, low cost test and can be done at outpatient clinic. Its sensitivity and specificity are good when compared to those of MRI, but when we need to diagnose associated soft tissue infection and planning the surgical management MRI was the image of choice.

  18. A Mobile-Based Surgical Simulation Application: A Comparative Analysis of Efficacy Using a Carpal Tunnel Release Module. (United States)

    Amer, Kamil M; Mur, Taha; Amer, Kamal; Ilyas, Asif M


    The utilization of surgical simulation continues to grow in medical training. The TouchSurgery application (app) is a new interactive virtual reality smartphone- or tablet-based app that offers a step-by-step tutorial and simulation for the execution of various operations. The purpose of this study was to compare the efficacy of the app versus traditional teaching modalities utilizing the "Carpal Tunnel Surgery" module. We hypothesized that users of the app would score higher than those using the traditional education medium indicating higher understanding of the steps of surgery. A total of 100 medical students were recruited to participate. The control group (n = 50) consisted of students learning about carpal tunnel release surgery using a video lecture utilizing slides. The study group (n = 50) consisted of students learning the procedure through the app. The content covered was identical in both groups but delivered through the different mediums. Outcome measures included comparison of test scores and overall app satisfaction. Test scores in the study group (89.3%) using the app were significantly higher than those in the control group (75.6%). Students in the study group rated the overall content validity, quality of graphics, ease of use, and usefulness to surgery preparation as very high (4.8 of 5). Students utilizing the app performed better on a standardized test examining the steps of a carpal tunnel release than those using a traditional teaching modality. The study findings lend support for the use of the app for medical students to prepare for and learn the steps for various surgical procedures. This study provides useful information on surgical simulation, which can be utilized to educate trainees for new procedures. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  19. Retrospective analysis of skin complications related to bone-anchored hearing aid implant: association with surgical technique, quality of life, and audiological benefit. (United States)

    Peñaranda, Daniel; Garcia, Juan Manuel; Aparicio, Maria Leonor; Montes, Felipe; Barón, Clemencia; Jiménez, Roberto C; Peñaranda, Augusto


    The bone-anchored hearing aid is an effective form of auditory rehabilitation. Due to the nature of the implant, the most common complications are skin related. A number of alternative surgical implantation techniques have been used to reduce the frequency and severity of skin complications, including the U-shaped graft and the linear incision. To assess skin complications and their association with surgical technique, quality of life, and audiological benefit in patients with bone-anchored hearing aids. This was a retrospective study conducted in a tertiary referral center in Bogotá, Colombia. Patients who had been fitted with a bone-anchored hearing aid implant (unilaterally or bilaterally) for at least 6 months were included in the study. The Holgers classification was used to classify skin complications (Grade 0=none; Grade 1=erythema; Grade 2=erythema and discharge; Grade 3=granulation tissue; and Grade 4=inflammation/infection resulting in the removal of the abutment). The Glasgow Benefit Inventory questionnaire was used to determine quality of life, and the Abbreviated Profile of Hearing Aid Benefit questionnaire was used to determine the subjective audiological benefit. A total of 37 patients were included in the study (30 with unilateral implants and 7 with bilateral implant). Of the 44 implants evaluated, 31 (70.3%) were associated with skin complications (7 [15.9%] Grade 1; 4 [9.1%] Grade 2; 15 [34.1%] Grade 3, 5 [11.4%] Grade 4). The U-shaped graft was statistically associated with major complications (Grades 3 and 4) compared with the linear incision technique (p=0.045). No statistically significant differences were found between Abbreviated Profile of Hearing Aid Benefit scores and severity of complications. Similarly, no differences were found between Glasgow Benefit Inventory physical health questions and skin complications. Despite the high frequency, skin complications did not seem to affect quality of life or subjective audiological benefits of

  20. Anatomy-Specific Virtual Reality Simulation in Temporal Bone Dissection: Perceived Utility and Impact on Surgeon Confidence. (United States)

    Locketz, Garrett D; Lui, Justin T; Chan, Sonny; Salisbury, Kenneth; Dort, Joseph C; Youngblood, Patricia; Blevins, Nikolas H


    Objective To evaluate the effect of anatomy-specific virtual reality (VR) surgical rehearsal on surgeon confidence and temporal bone dissection performance. Study Design Prospective pre- and poststudy of a novel virtual surgical rehearsal platform. Setting Academic otolaryngology-head and neck surgery residency training programs. Subjects and Methods Sixteen otolaryngology-head and neck surgery residents from 2 North American training institutions were recruited. Surveys were administered to assess subjects' baseline confidence in performing 12 subtasks of cortical mastoidectomy with facial recess. A cadaver temporal bone was randomly assigned to each subject. Cadaver specimens were scanned with a clinical computed tomography protocol, allowing the creation of anatomy-specific models for use in a VR surgical rehearsal platform. Subjects then rehearsed a virtual mastoidectomy on data sets derived from their specimens. Surgical confidence surveys were administered again. Subjects then dissected assigned cadaver specimens, which were blindly graded with a modified Welling scale. A final survey assessed the perceived utility of rehearsal on dissection performance. Results Of 16 subjects, 14 (87.5%) reported a significant increase in overall confidence after conducting an anatomy-specific VR rehearsal. A significant correlation existed between perceived utility of rehearsal and confidence improvement. The effect of rehearsal on confidence was dependent on trainee experience and the inherent difficulty of the surgical subtask. Postrehearsal confidence correlated strongly with graded dissection performance. Subjects rated anatomy-specific rehearsal as having a moderate to high contribution to their dissection performance. Conclusion Anatomy-specific virtual rehearsal improves surgeon confidence in performing mastoid dissection, dependent on surgeon experience and task difficulty. The subjective confidence gained through rehearsal correlates positively with subsequent

  1. Diagnosis of simulated condylar bone defects using panoramic radiography, spiral tomography and cone-beam computed tomography: A comparison study


    Salemi, Fatemeh; Shokri, Abbas; Mortazavi, Hamed; Baharvand, Maryam


    Objectives: Radiographic examination is one of the most important parts of the clinical assessment routine for temporomandibular disorders. The aim of this study was to compare the diagnostic accuracy of cone-beam computed tomography(CBCT) with panoramic radiography and spiral computed tomography for the detection of the simulated mandibular condyle bone lesions. Study Design: The sample consisted of 10 TMJs from 5 dried human skulls. Simulated erosive and osteophytic lesions were created in ...

  2. Simulation of mechanical behavior and optimization of simulated injection molding process for PLA based antibacterial composite and nanocomposite bone screws using central composite design. (United States)

    Heidari, Behzad Shiroud; Oliaei, Erfan; Shayesteh, Hadi; Davachi, Seyed Mohammad; Hejazi, Iman; Seyfi, Javad; Bahrami, Mozhgan; Rashedi, Hamid


    In this study, injection molding of three poly lactic acid (PLA) based bone screws was simulated and optimized through minimizing the shrinkage and warpage of the bone screws. The optimization was carried out by investigating the process factors such as coolant temperature, mold temperature, melt temperature, packing time, injection time, and packing pressure. A response surface methodology (RSM), based on the central composite design (CCD), was used to determine the effects of the process factors on the PLA based bone screws. Upon applying the method of maximizing the desirability function, optimization of the factors gave the lowest warpage and shrinkage for nanocomposite PLA bone screw (PLA9). Moreover, PLA9 has the greatest desirability among the selected materials for bone screw injection molding. Meanwhile, a finite element analysis (FE analysis) was also performed to determine the force values and concentration points which cause yielding of the screws under certain conditions. The Von-Mises stress distribution showed that PLA9 screw is more resistant against the highest loads as compared to the other ones. Finally, according to the results of injection molding simulations, the design of experiments (DOE) and structural analysis, PLA9 screw is recommended as the best candidate for the production of biomedical materials among all the three types of screws. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Localized ''pseudofracture'' type of pathologic reconstruction of costal bone structure following surgical and radiation treatment of breast cancer

    International Nuclear Information System (INIS)

    Grigorov, G.; Dobrev, D.; Syrmadzhieva, S.; Todorov, J.


    In a study of the X-ray images of the thorax of 469 women, who had undergone operative treatment and postoperative radiation therapy of breast cancer, the authors detected in 11 patients the localized ''pseudofracture'' type of pathologic reconstruction of the costal bone structure. In 10 patients the changes were localized in the anterior part of the second ribs, and in one - in the anterior part of the 5th rib. They were detected on X-ray examination 11 to 15 months after the onset of radiation treatment and clinically ran a symptomless course. Roentgenographically the changes consisted in: transverse rarefication strips with perifocal streaky densities; transverse rarefication strips and fine pseudocystic reconstruction of the adjacent bone structure; transverse rarefication strips with a gradual reconstruction of the adjacent lateral segment of the rib, till its complete roentgenologic disappearance. There was no periosteal reaction. The second and the third type of X-ray changes resembled metastasis. (author)

  4. Achieving Accreditation Council for Graduate Medical Education duty hours compliance within advanced surgical training: a simulation-based feasibility assessment. (United States)

    Obi, Andrea; Chung, Jennifer; Chen, Ryan; Lin, Wandi; Sun, Siyuan; Pozehl, William; Cohn, Amy M; Daskin, Mark S; Seagull, F Jacob; Reddy, Rishindra M


    Certain operative cases occur unpredictably and/or have long operative times, creating a conflict between Accreditation Council for Graduate Medical Education (ACGME) rules and adequate training experience. A ProModel-based simulation was developed based on historical data. Probabilistic distributions of operative time calculated and combined with an ACGME compliant call schedule. For the advanced surgical cases modeled (cardiothoracic transplants), 80-hour violations were 6.07% and the minimum number of days off was violated 22.50%. There was a 36% chance of failure to fulfill any (either heart or lung) minimum case requirement despite adequate volume. The variable nature of emergency cases inevitably leads to work hour violations under ACGME regulations. Unpredictable cases mandate higher operative volume to ensure achievement of adequate caseloads. Publically available simulation technology provides a valuable avenue to identify adequacy of case volumes for trainees in both the elective and emergency setting. Copyright © 2015 Elsevier Inc. All rights reserved.


    Directory of Open Access Journals (Sweden)

    POPA Laurentiu Dragos


    Full Text Available To understand the problems, which appear in every human joint, it is very important to know the anatomy and morphology of the human bones and the way in which the components are working together to realize a normal functionality. For this purpose was used a CAD parametric software which permits to define models with a high degree of difficulty. First, it was used a CT or MRI device to obtain the parallel sections to study each component of the bone. A 3D scanner can be used only for the outer geometry. In the second step the images were transferred to a 2D CAD software, like AutoCAD, where the outer and inner contours of the bone were approximate to polygonal lines composed by many segments. After this, the contours were transferred to a 3D CAD software, like SolidWorks, where, step by step, and section by section, was defined the virtual bone component. Additionally to the main shape can be attached other Loft, Round or Dome shapes. For some components, as vertebrae, mandible or skull bones, can be used a preliminary model obtained by parallel sections. Starting from this, the model can be defined using the main 3D curves and we can get the final virtual solid model. In some simulations, the soft components, as muscles or ligaments, were included in simulations using non-linear virtual springs. Also, sometimes were used implants or prosthetic elements. In the final of the paper, were extracted important conclusions.

  6. Simulation of Surgical Cutting in Deformable Bodies using a Game Engine

    DEFF Research Database (Denmark)

    Jørgensen, Martin Kibsgaard; Kronborg Thomsen, Kasper; Kraus, Martin


    Simulators as a training tool for surgeons are becoming more important with the increase of minimally invasive surgery and a wish to limit training on animals, especially in the field of robotic surgery. Accessibility to surgery simulators is currently limited and the ability to cut is restricted...

  7. An Evaluation of the Diagnostic Accuracy of the Grade of Preoperative Biopsy Compared to Surgical Excision in Chondrosarcoma of the Long Bones

    Directory of Open Access Journals (Sweden)

    Robert Jennings


    Full Text Available Chondrosarcoma is the second most common primary malignant bone tumour. Distinguishing between grades is not necessarily straightforward and may alter the disease management. We evaluated the correlation between histological grading of the preoperative image-guided needle biopsy and the resection specimen of 78 consecutive cases of chondrosarcoma of the femur, humerus, and tibia. In 11 instances, there was a discrepancy in histological grade between the biopsy and surgical specimen. Therefore, there was an 85.9% (67/78 accuracy rate for pre-operative histological grading of chondrosarcoma, based on needle biopsy. However, the accuracy of the diagnostic biopsy to distinguish low-grade from high-grade chondrosarcoma was 93.6% (73/78. We conclude that accurate image-guided biopsy is a very useful adjunct in determining histological grade of chondrosarcoma and the subsequent treatment plan. At present, a multidisciplinary approach, comprising experienced orthopaedic surgeons, radiologists, and pathologists, offers the most reliable means of accurately diagnosing and grading of chondrosarcoma of long bones.

  8. Three-dimensional Simulation of Quantitative Ultrasound in Cancellous Bone Using the Echographic Response of a Metallic Pin. (United States)

    Nagatani, Yoshiki; Guipieri, Séraphin; Nguyen, Vu-Hieu; Chappard, Christine; Geiger, Didier; Naili, Salah; Haїat, Guillaume


    Degenerative discopathy is a common pathology that may require spine surgery. A metallic cylindrical pin is inserted into the vertebral body to maintain soft tissues and may be used as a reflector of ultrasonic wave to estimate bone density. The first aim of this paper is to validate a three-dimensional (3-D) model to simulate the ultrasonic propagation in a trabecular bone sample in which a metallic pin has been inserted. We also aim at determining the effect of changes of bone volume fraction (BV/TV) and of positioning errors on the quantitative ultrasound (QUS) parameters in this specific configuration. The approach consists in coupling finite-difference time-domain simulation with X-ray microcomputed tomography. The correlation coefficient between experimental and simulated speed of sound (SOS)-respectively, broadband ultrasonic attenuation (BUA)-was equal to 0.90 (respectively, 0.55). The results show a significant correlation of SOS with BV/TV ( R = 0.82), while BUA values exhibit a nonlinear behavior versus BV/TV. The orientation of the pin should be controlled with an accuracy of around 1° to obtain accurate results. The results indicate that using the ultrasonic wave reflected by a pin has a potential to estimate the bone density. SOS is more reliable than BUA due to its lower sensitivity to the tilt angle.

  9. The Relationship of Endoscopic Proficiency to Educational Expense for Virtual Reality Simulator Training Amongst Surgical Trainees. (United States)

    Raque, Jessica; Goble, Adam; Jones, Veronica M; Waldman, Lindsey E; Sutton, Erica


    With the introduction of Fundamentals of Endoscopic Surgery, training methods in flexible endoscopy are being augmented with simulation-based curricula. The investment for virtual reality simulators warrants further research into its training advantage. Trainees were randomized into bedside or simulator training groups (BED vs SIM). SIM participated in a proficiency-based virtual reality curriculum. Trainees' endoscopic skills were rated using the Global Assessment of Gastrointestinal Endoscopic Skills (GAGES) in the patient care setting. The number of cases to reach 90 per cent of the maximum GAGES score and calculated costs of training were compared. Nineteen residents participated in the study. There was no difference in the average number of cases required to achieve 90 per cent of the maximum GAGES score for esophagogastroduodenoscopy, 13 (SIM) versus11 (BED) (P = 0.63), or colonoscopy 21 (SIM) versus 4 (BED) (P = 0.34). The average per case cost of training for esophagogastroduodenoscopy was $35.98 (SIM) versus $39.71 (BED) (P = 0.50), not including the depreciation costs associated with the simulator ($715.00 per resident over six years). Use of a simulator appeared to increase the cost of training without accelerating the learning curve or decreasing faculty time spent in instruction. The importance of simulation in endoscopy training will be predicated on more cost-effective simulators.

  10. Osteoblastomatosis of bone. A benign, multifocal osteoblastic lesion, distinct from osteoid osteoma and osteoblastoma, radiologically simulating a vascular tumor

    Energy Technology Data Exchange (ETDEWEB)

    Kyriakos, Michael [Washington University School of Medicine, Division of Surgical Pathology, Campus Box 8118, St. Louis, MO (United States); El-Khoury, Georges Y. [University of Iowa, Department of Radiology, Roy J. and Lucille A. Carver School of Medicine, Iowa City, IA (United States); McDonald, Douglas J. [Washington University School of Medicine, Department of Orthopaedic Surgery, St. Louis, MO (United States); Buckwalter, Joseph A. [University of Iowa, Department of Orthopaedics, Roy J. and Lucille A. Carver School of Medicine, Iowa City, IA (United States); Sundaram, Murali [Cleveland Clinic Foundation, Department of Radiology, Cleveland, OH (United States); DeYoung, Barry [University of Iowa, Department of Pathology, School of Medicine, Iowa City, IA (United States); O' Brien, Michael P. [University of Wisconsin Hospital, Department of Radiology, Madison, WI (United States)


    Two adult patients are described with multifocal osteolytic lesions radiologically simulating a vascular tumor. One patient had multiple bones involved. Histologically, the individual lesions had the features of the nidus of osteoid osteoma/osteoblastoma. A review of the English language medical literature yielded only one other reported case with similar features. The process is designated as osteoblastomatosis to indicate its bone-forming character, prominent osteoblast proliferation, and multiplicity. The cases are distinguished from multifocal/multicentric osteoid osteoma and osteoblastoma, and from benign and malignant vascular tumors. (orig.)

  11. Osteoblastomatosis of bone. A benign, multifocal osteoblastic lesion, distinct from osteoid osteoma and osteoblastoma, radiologically simulating a vascular tumor

    International Nuclear Information System (INIS)

    Kyriakos, Michael; El-Khoury, Georges Y.; McDonald, Douglas J.; Buckwalter, Joseph A.; Sundaram, Murali; DeYoung, Barry; O'Brien, Michael P.


    Two adult patients are described with multifocal osteolytic lesions radiologically simulating a vascular tumor. One patient had multiple bones involved. Histologically, the individual lesions had the features of the nidus of osteoid osteoma/osteoblastoma. A review of the English language medical literature yielded only one other reported case with similar features. The process is designated as osteoblastomatosis to indicate its bone-forming character, prominent osteoblast proliferation, and multiplicity. The cases are distinguished from multifocal/multicentric osteoid osteoma and osteoblastoma, and from benign and malignant vascular tumors. (orig.)

  12. In Vivo Evaluation of Two-Piece Implants Placed Following One-Stage and Two-Stage Surgical Protocol in Posterior Mandibular Region. Assessment of Alterations in Crestal Bone Level. (United States)

    Gulati, Minkle; Govila, Vivek; Verma, Sunil; Rajkumar, Balakrishnan; Anand, Vishal; Aggarwal, Anuj; Jain, Nikil


    Endosseous implants can be placed following either two-stage technique requiring second-stage surgery or one-stage technique, which does not involve a second surgical intervention. The present study was undertaken to evaluate and compare the changes in crestal bone level when two-piece implants were placed in posterior mandibular region following one-stage and two-stage surgical protocol. A parallel group randomized prospective study was designed in which 20 two-piece implants were placed in the posterior mandibular region of 16 partially edentulous healthy patients following either one-stage (Group I) or a two-stage surgical protocol (Group II). Alterations in crestal bone level were assessed with the help of DentaScan at baseline, that is, at the time of implant placement, third month and sixth month. Nonsignificant differences were seen in both groups in terms of changes in crestal bone level at the final evaluation. Hence, it could be concluded that two-piece implants can be placed following one-stage surgical protocol as predictably as when two-stage surgical technique is followed. © 2013 Wiley Periodicals, Inc.

  13. Building an efficient surgical team using a bench model simulation: construct validity of the Legacy Inanimate System for Endoscopic Team Training (LISETT). (United States)

    Zheng, B; Denk, P M; Martinec, D V; Gatta, P; Whiteford, M H; Swanström, L L


    Complex laparoscopic tasks require collaboration of surgeons as a surgical team. Conventionally, surgical teams are formed shortly before the start of the surgery, and team skills are built during the surgery. There is a need to establish a training simulation to improve surgical team skills without jeopardizing the safety of surgery. The Legacy Inanimate System for Laparoscopic Team Training (LISETT) is a bench simulation designed to enhance surgical team skills. The reported project tested the construct validity of LISETT. The research question was whether the LISETT scores show progressive improvement correlating with the level of surgical training and laparoscopic team experience or not. With LISETT, two surgeons are required to work closely to perform two laparoscopic tasks: peg transportation and suturing. A total of 44 surgical dyad teams were recruited, composed of medical students, residents, laparoscopic fellows, and experienced surgeons. The LISETT scores were calculated according to the speed and accuracy of the movements. The LISETT scores were positively correlated with surgical experience, and the results can be generalized confidently to surgical teams (Pearson's coefficient, 0.73; p = 0.001). To analyze the influences of individual skill and team dynamics on LISETT performance, team quality was rated by team members using communication and cooperation characters after each practice. The LISETT scores are positively correlated with self-rated team quality scores (Pearson's coefficient, 0.39; p = 0.008). The findings proved LISETT to be a valid system for assessing cooperative skills of a surgical team. By increasing practice time, LISETT provides an opportunity to build surgical team skills, which include effective communication and cooperation.

  14. Mesenchymal stem cell therapy regenerates the native bone-tendon junction after surgical repair in a degenerative rat model.

    Directory of Open Access Journals (Sweden)

    Geoffroy Nourissat

    Full Text Available BACKGROUND: The enthesis, which attaches the tendon to the bone, naturally disappears with aging, thus limiting joint mobility. Surgery is frequently needed but the clinical outcome is often poor due to the decreased natural healing capacity of the elderly. This study explored the benefits of a treatment based on injecting chondrocyte and mesenchymal stem cells (MSC in a new rat model of degenerative enthesis repair. METHODOLOGY: The Achilles' tendon was cut and the enthesis destroyed. The damage was repaired by classical surgery without cell injection (group G1, n = 52 and with chondrocyte (group G2, n = 51 or MSC injection (group G3, n = 39. The healing rate was determined macroscopically 15, 30 and 45 days later. The production and organization of a new enthesis was assessed by histological scoring of collagen II immunostaining, glycoaminoglycan production and the presence of columnar chondrocytes. The biomechanical load required to rupture the bone-tendon junction was determined. PRINCIPAL FINDINGS: The spontaneous healing rate in the G1 control group was 40%, close to those observed in humans. Cell injection significantly improved healing (69%, p = 0.0028 for G2 and p = 0.006 for G3 and the load-to-failure after 45 days (p<0.05 over controls. A new enthesis was clearly produced in cell-injected G2 and G3 rats, but not in the controls. Only the MSC-injected G3 rats had an organized enthesis with columnar chondrocytes as in a native enthesis 45 days after surgery. CONCLUSIONS: Cell therapy is an efficient procedure for reconstructing degenerative entheses. MSC treatment produced better organ regeneration than chondrocyte treatment. The morphological and biomechanical properties were similar to those of a native enthesis.

  15. Tear patterns, surgical repair, and clinical outcomes of patellar tendon ruptures after anterior cruciate ligament reconstruction with a bone-patellar tendon-bone autograft. (United States)

    Benner, Rodney W; Shelbourne, K Donald; Urch, Scott E; Lazarus, David


    Patellar tendon ruptures are rare after graft harvest for anterior cruciate ligament (ACL) reconstruction. Few reports are available in the literature. To report the common tear patterns and results of treatment with tendon repair and cable augmentation. Case series; Level of evidence, 4. All tendon ruptures were repaired to bone with suture anchors and augmented with a Dall-Miles cable, followed by an aggressive rehabilitation protocol. The tear location was recorded. Range of motion, strength, and subjective survey testing were conducted preoperatively and postoperatively. Thirteen patellar tendon ruptures were found from our database of 5364 ACL reconstructions, for an incidence of 0.24%. Seven ruptures occurred from the patellar origin medially and the tibial attachment laterally in a Z-shaped pattern. Four were completely distal, and 2 were completely proximal ruptures. All patients exhibited early flexion loss, but 11 of 13 patients maintained full, terminal hyperextension throughout treatment. The mean postoperative side-to-side flexion deficit was 33° at 1 month, 6° at 3 months, and 3° at latest follow-up at a mean of 4.8 years after tendon repair (range, 1-16 years). By International Knee Documentation Committee (IKDC) criteria, 10 patients had normal flexion, and 3 were nearly normal at latest follow-up. Twelve patients had normal extension, and 1 had nearly normal extension at latest follow-up. Mean isokinetic quadriceps muscle strength was 68.7% of the other side at 3 months after repair and 100.0% at latest follow-up, occurring at a mean of 47.5 months (range, 12-120 months). At a mean of 2 years (range, 1-4 years) after repair, the mean modified Noyes subjective score was 89.8 ± 9.2. Patellar tendon ruptures are rare after ACL graft harvest. These ruptures usually occur in either a proximal-medial and distal-lateral pattern or an entirely distal pattern, in contrast to the proximal-only tear pattern commonly observed in unharvested patellar

  16. Influence of Deformation and Stress between Bone and Implant from Various Bite Forces by Numerical Simulation Analysis

    Directory of Open Access Journals (Sweden)

    Hsin-Chung Cheng


    Full Text Available Endosseous oral implant is applied for orthodontic anchorage in subjects with multiple tooth agenesis. Its effectiveness under orthodontic loading has been demonstrated clinically and experimentally. This study investigates the deformation and stress on the bone and implant for different bite forces by three-dimensional (3D finite element (FE methods. A numerical simulation of deformation and stress distributions around implants was used to estimate the survival life for implants. The model was applied to determine the pattern and distribution of deformations and stresses within the endosseous implant and on supporting tissues when the endosseous implant is used for orthodontic anchorage. A threaded implant was placed in an edentulous segment of a human mandible with cortical and cancellous bone. Analytical results demonstrate that maximum stresses were always located around the implant neck in marginal bone. The results also reveal that the stress for oblique force has the maximum value followed by the horizontal force; the vertical force causes the stress to have the minimum value between implant and bone. Thus, this area should be preserved clinically to maintain the structure and function of a bone implant.

  17. Simulation of acoustic guided wave propagation in cortical bone using a semi-analytical finite element method. (United States)

    Pereira, Daniel; Haiat, Guillaume; Fernandes, Julio; Belanger, Pierre


    Axial transmission techniques have been extensively studied for cortical bone quality assessment. However, the modeling of ultrasonic guided waves propagation in such a complex medium remains challenging. The aim of this paper is to develop a semi-analytical finite element method to simulate the propagation of guided waves in an irregular, multi-layer, and heterogeneous bone cross-section modeled with anisotropic and viscoelastic material properties. The accuracy of the simulations was verified against conventional time-domain three-dimensional finite element. The method was applied in the context of axial transmission in bone to investigate the feasibility of first arrival signal (FAS) to monitor degradation of intracortical properties at low frequency. Different physiopathological conditions for the intracortical region, varying from healthy to osteoporotic, were monitored through FAS velocity using a 10-cycle tone burst excitation centered at 32.5 kHz. The results show that the variation in FAS velocity is mainly associated with four of the eight modes supported by the waveguide, varying with velocity values between 550 and 700 m/s along the different scenarios. Furthermore, the FAS velocity is shown to be associated with the group velocity of the mode with the highest relative amplitude contribution at each studied scenario. However, because of the evolution of the mode with the highest contribution, the FAS velocity is shown to be limited to discriminate intracortical bone properties at low frequency.

  18. Diagnosis of simulated condylar bone defects using panoramic radiography, spiral tomography and cone-beam computed tomography: A comparison study. (United States)

    Salemi, Fatemeh; Shokri, Abbas; Mortazavi, Hamed; Baharvand, Maryam


    Radiographic examination is one of the most important parts of the clinical assessment routine for temporomandibular disorders. The aim of this study was to compare the diagnostic accuracy of cone-beam computed tomography(CBCT) with panoramic radiography and spiral computed tomography for the detection of the simulated mandibular condyle bone lesions. The sample consisted of 10 TMJs from 5 dried human skulls. Simulated erosive and osteophytic lesions were created in 3 different sizes using round diamond bur and bone chips, respectively. Panoramic radiography, spiral tomography and cone-beam computed tomography were used in defect detection. Data were statistically analyzed with the Mann-Whitney test. The reliability and degrees of agreement between two observers were also determined by the mean of Cohen's Kappa analysis. CBCT had a statistically significant superiority than other studied techniques in detection of both erosive and osteophytic lesions with different sizes. There were significant differences between tomography and panoramic in correct detection of both erosive and osteophytic lesions with 1mm and 1.5 mm in size. However, there were no significant differences between Tomography and Panoramic in correct detection of both erosive and osteophytic lesions with 0.5 mm in size. CBCT images provide a greater diagnostic accuracy than spiral tomography and panoramic radiography in the detection of condylar bone erosions and osteophytes. Key words:Bone defect, Condyle, CBCT, Panoramic, radiography.

  19. Contemporary virtual reality laparoscopy simulators: quicksand or solid grounds for assessing surgical trainees?

    NARCIS (Netherlands)

    Thijssen, Anthony S.; Schijven, Marlies P.


    BACKGROUND: A demand for safe, efficient laparoscopic training tools has prompted the introduction of virtual reality (VR) laparoscopic simulators, which might be used for performance assessment. The purpose of this review is to determine the value of VR metrics in laparoscopic skills assessment.

  20. Combining Latin Hypercube Designs and Discrete Event Simulation in a Study of a Surgical Unit

    DEFF Research Database (Denmark)

    Dehlendorff, Christian; Andersen, Klaus Kaae; Kulahci, Murat

    Summary form given only:In this article experiments on a discrete event simulation model for an orthopedic surgery are considered. The model is developed as part of a larger project in co-operation with Copenhagen University Hospital in Gentofte. Experiments on the model are performed by using...

  1. Simulation of Surgical Cutting in Deformable Bodies using a Game Engine

    DEFF Research Database (Denmark)

    Jørgensen, Martin Kibsgaard; Kronborg Thomsen, Kasper; Kraus, Martin


    are implemented using a spring mass model combined with a volumetric tetrahedral mesh. The cutting algorithm is semi-progressive and allows for arbitrary cuts in the deformable objects. The prototype was evaluated by a chief surgeon with expertise in robot surgery and experience with commercial simulators...

  2. Three-dimensional computer-assisted surgical simulation and intraoperative navigation in orthognathic surgery: A literature review

    Directory of Open Access Journals (Sweden)

    Hsiu-Hsia Lin


    Full Text Available By incorporating three-dimensional (3D imaging and computer-aided design and manufacturing techniques, 3D computer-assisted technology has been applied widely to provide accurate guidance for assessment and treatment planning in clinical practice. This technology has recently been used in orthognathic surgery to improve surgical planning and outcome. The modality will gradually become popular. This study reviewed the literature concerning the use of computer-assisted techniques in orthognathic surgery including surgical planning, simulation, intraoperative translation of the virtual surgery, and postoperative evaluation. A Medline, PubMed, ProQuest, and ScienceDirect search was performed to find relevant articles with regard to 3D computer-assisted orthognathic surgery in the past 10 years. A total of 460 articles were revealed, out of which 174 were publications addressed the topic of this study. The purpose of this article is to present an overview of the state-of-art methods for 3D computer-assisted technology in orthognathic surgery. From the review we can conclude that the use of computer-assisted technique in orthognathic surgery provides the benefit of optimal functional and aesthetic results, patient satisfaction, precise translation of the treatment plan, and facilitating intraoperative manipulation.

  3. A pilot study to determine medical laser generated air contaminant emission rates for a simulated surgical procedure. (United States)

    Lippert, Julia F; Lacey, Steven E; Lopez, Ramon; Franke, John; Conroy, Lorraine; Breskey, John; Esmen, Nurtan; Liu, Li


    The U.S. Occupational Safety and Health Administration (OSHA) estimates that half a million health-care workers are exposed to laser surgical smoke each year. The purpose of this study was to establish a methodology to (1) estimate emission rates of laser-generated air contaminants (LGACs) using an emission chamber, and to (2) perform a screening study to differentiate the effects of three laser operational parameters. An emission chamber was designed, fabricated, and assessed for performance to estimate the emission rates of gases and particles associated with LGACs during a simulated surgical procedure. Two medical lasers (Holmium Yttrium Aluminum Garnet [Ho:YAG] and carbon dioxide [CO2]) were set to a range of plausible medical laser operational parameters in a simulated surgery to pyrolyze porcine skin generating plume in the emission chamber. Power, pulse repetition frequency (PRF), and beam diameter were evaluated to determine the effect of each operational parameter on emission rate using a fractional factorial design. The plume was sampled for particulate matter and seven gas phase combustion byproduct contaminants (benzene, ethylbenzene, toluene, formaldehyde, hydrogen cyanide, carbon dioxide, and carbon monoxide): the gas phase emission results are presented here. Most of the measured concentrations of gas phase contaminants were below their limit of detection (LOD), but detectable measurements enabled us to determine laser operation parameter influence on CO2 emissions. Confined to the experimental conditions of this screening study, results indicated that beam diameter was statistically significantly influential and power was marginally statistically significant to emission rates of CO2 when using the Ho:YAG laser but not with the carbon dioxide laser; PRF was not influential vis-a-vis emission rates of these gas phase contaminants.

  4. Objective evaluation of minimally invasive surgical skills for transplantation. Surgeons using a virtual reality simulator. (United States)

    Dănilă, R; Gerdes, B; Ulrike, H; Domínguez Fernández, E; Hassan, I


    The learning curve in laparoscopic surgery may be associated with higher patient risk, which is unacceptable in the setting of kidney donation. Virtual reality simulators may increase the safety and efficiency of training in laparoscopic surgery. The aim of this study was to investigate if the results of a training session reflect the actual skill level of transplantation surgeons and whether the simulator could differentiate laparoscopic experienced transplantation surgeon from advanced trainees. 16 subjects were assigned to one of two groups: 5 experienced transplantation surgeon and 11 advanced residents, with only assistant role during transplantation. The level of performance was measured by a relative scoring system that combines single parameters assessed by the computer. The higher the level of transplantation experience of a participant, the higher the laparoscopic performance. Experienced transplantation surgeons showed statistically significant better scores than the advanced group for time and precision parameters. Our results show that performance of the various tasks on the simulator corresponds to the respective level of experience in transplantation surgery in our research groups. This study confirms construct validity for the LapSim. It thus measures relevant skills and can be integrated in an endoscopic training and assessment curriculum for transplantations surgeons.

  5. Simulation for training in oral cancer biopsy: a surgical model and feedback from GDPs. (United States)

    Seoane, Juan; Varela-Centelles, Pablo; Esparza-Gómez, Germán; Cerero-Lapiedra, Rocío; Seoane-Romero, Juan M; Diz, Pedro


    To describe a new bench model for oral precancer/cancer biopsy training and to assess its effectiveness in terms of trainees' perception. Cross-sectional, descriptive, performed on 424 general dental practitioners (GDP) who undertook biopsies on a pig tongue. The participants were assessed by direct observation for 2.5 hours using specific check-lists and by means of a self-applied questionnaire. The workshop was perceived as "very interesting" even by those with previous surgical experience (Xi - Xj = 0.07; 95%CI= -0.20-0.09). Most GDPs considered themselves able to undertake oral biopsies on real patients after the workshop. Those who had previously received theoretical continuous education courses on oral biopsy scored higher values within the group (Xi - Xj = 0.20; 95%CI= 0.04-0.37). There is a need for including clinical abilities workshops when instructing on oral biopsy techniques. More studies are needed to validate the procedure and to address cognitive and communication skills.

  6. Identifying Opportunities for Virtual Reality Simulation in Surgical Education: A Review of the Proceedings from the Innovation, Design, and Emerging Alliances in Surgery (IDEAS) Conference: VR Surgery. (United States)

    Olasky, Jaisa; Sankaranarayanan, Ganesh; Seymour, Neal E; Magee, J Harvey; Enquobahrie, Andinet; Lin, Ming C; Aggarwal, Rajesh; Brunt, L Michael; Schwaitzberg, Steven D; Cao, Caroline G L; De, Suvranu; Jones, Daniel B


    To conduct a review of the state of virtual reality (VR) simulation technology, to identify areas of surgical education that have the greatest potential to benefit from it, and to identify challenges to implementation. Simulation is an increasingly important part of surgical training. VR is a developing platform for using simulation to teach technical skills, behavioral skills, and entire procedures to trainees and practicing surgeons worldwide. Questions exist regarding the science behind the technology and most effective usage of VR simulation. A symposium was held to address these issues. Engineers, educators, and surgeons held a conference in November 2013 both to review the background science behind simulation technology and to create guidelines for its use in teaching and credentialing trainees and surgeons in practice. Several technologic challenges were identified that must be overcome in order for VR simulation to be useful in surgery. Specific areas of student, resident, and practicing surgeon training and testing that would likely benefit from VR were identified: technical skills, team training and decision-making skills, and patient safety, such as in use of electrosurgical equipment. VR simulation has the potential to become an essential piece of surgical education curriculum but depends heavily on the establishment of an agreed upon set of goals. Researchers and clinicians must collaborate to allocate funding toward projects that help achieve these goals. The recommendations outlined here should guide further study and implementation of VR simulation. © The Author(s) 2015.

  7. A Simulation Curriculum for Management of Trauma and Surgical Critical Care Patients. (United States)

    Miyasaka, Kiyoyuki W; Martin, Niels D; Pascual, Jose L; Buchholz, Joseph; Aggarwal, Rajesh


    Expectations continue to rise for residency programs to provide integrated simulation training to address clinical competence. How to implement such training sustainably remains a challenge. We developed a compact module for first-year surgery residents integrating theory with practice in high-fidelity simulations, to reinforce the preparedness and confidence of junior residents in their ability to manage common emergent patient care scenarios in trauma and critical care surgery. The 3-day module features a combination of simulated patient encounters using standardized patients and electronic manikins, didactic sessions, and hands-on training. Manikin-based scenarios developed in-house were used to teach trauma and critical care management concepts and skills. Separate scenarios in collaboration with the regional organ donation program addressed communication in difficult situations such as brain death. Didactic material based on contemporary evidence, as well as skills stations, was developed to complement the scenarios. Residents were surveyed before and after training on their confidence in meeting the 14 learning objectives of the curriculum on a 5-point Likert scale. Data from 15 residents who underwent this training show an overall improvement in confidence across all learning objectives defined for the module, with confidence scores before to after training improving significantly from 2.8 (σ = 0.85, median = 3) to 3.9 (σ = 0.87, median = 4) of 5, p < 0.001. Although female residents reported higher posttraining confidence scores compared with male residents (average 4.2 female vs 3.8 male, p = 0.002), there were no other significant differences in confidence scores or changes to scores owing to resident sex or program status (categorical or preliminary). We successfully implemented a multimodal simulation-based curriculum that provides skills training integrated with the clinical context of managing trauma and critical care patients, simultaneously

  8. Distribution of innate ability for surgery amongst medical students assessed by an advanced virtual reality surgical simulator. (United States)

    Moglia, Andrea; Ferrari, Vincenzo; Morelli, Luca; Melfi, Franca; Ferrari, Mauro; Mosca, Franco; Cuschieri, Alfred


    Surgery is a craft profession requiring individuals with specific, well-documented innate aptitude for manipulative skills. Yet in most countries, the current selection process of surgical trainees does not include aptitude testing for the psychomotor and manipulative skills of candidates. A total of 125 participants (121 medical students and four expert surgeons) performed all 26 exercises of the da Vinci Skills Simulator, with six exercises being identified as metrics of aptitude for manipulative and psychomotor skills. The expert surgeons were enrolled as the control group to validate the performance of the most talented students. Eight students (6.6%) significantly outperformed the remaining 113, obtaining a median value of the sum of weighted overall score on the six selected exercises of 52.7% versus 21.0% (p manipulative and psychomotor abilities, the present investigation has documented two subpopulations that fall outside the norm for the group of medical students recruited for the study: (i) a small group (6.6%) with a high level and (ii) a larger cohort (11.6%) with low level (significantly below the norm) innate aptitude for surgery. Exposure to video game experience did not appear to influence performances on the da Vinci Skills Simulator.

  9. Effects of electric and magnetic loadings on bone surface remodeling: a model modification and simulation. (United States)

    Kazerooni, Anahita Fathi; Rabbani, Mohsen; Yazdchi, Mohammadreza; Kasiri, Saeid; Rad, Hamidreza Saligheh


    This paper presents a new modification to the previous model of bone surface remodeling under electric and magnetic loadings. For this study, the thermo-electro-magneto-elastic model of bone surface remodeling is used. This model is modified by considering an important phenomenon occurring in living bone through its adaptation to external loadings called desensitization. In fact, bone cells lose their responsiveness and sensitivity to long-term external loadings, i.e., they become desensitized. Therefore, bone cells need a recovery period, during which they become resensitized. In this work, this phenomenon is considered in the original model. The effects of various electric and magnetic loading conditions, including various frequencies, waveforms and pulse duty cycles, are explored on the modified model and compared to the original model. The modified model is also searched for the optimal frequency and duty cycle, to obtain the best bone growth response under electromagnetic fields. The results of this paper show that the modified model is consistent with experimental observations. In addition, it is indicated that this modified model in contrast to the original model, is sensitive to frequency. It is shown that the optimal frequency of loading for the modified model is 1 Hertz (Hz), and the pulse duty cycles up to 50% are sufficient for bone remodeling to reach its maximum value.

  10. A biomechanical comparison of headless tapered variable pitch and AO cortical bone screws for fixation of a simulated slab fracture in equine third carpal bones. (United States)

    Bueno, Aloisio C D; Galuppo, Larry D; Taylor, Kenneth T; Jensen, David G; Stover, Susan M


    To compare the mechanical shear strengths and stiffnesses obtained from in vitro testing of a simulated complete third carpal bone (C3) frontal plane radial facet slab fracture (osteotomy) stabilized with either a 4/5 Acutrak (AT) compression screw or a 4.5-mm AO cortical bone (AO) screw inserted in lag fashion. Drilling, tapping, and screw insertion torques, forces, and times also were compared between AT and AO implants. In vitro biomechanical assessment of site preparation, screw insertion, and shear failure test variables of bone screw stabilized simulated C3 slab fracture in paired cadaveric equine carpi. Eight pairs of cadaveric equine C3 without orthopedic abnormalities. Standardized simulated C3 slab fractures were repaired with either AO or AT screws (AO/C3 and AT/C3 groups, respectively). Drilling, tapping, and screw insertion torques, forces, and times were measured with a materials testing machine for each screw type. Repaired specimens were tested in axially oriented shear until failure. Paired Students t-tests were used to assess differences between site preparation, screw insertion, and shear testing variables. Significance was set at P bone fragment measurements of the standardized simulated C3 slab fractures created for AO or AT screws. There were no significant differences for mean and maximum drilling torques; however, the tapered AT drill had greater maximum drilling force compared with the 3.2-mm and 4.5-mm AO drill bits. Mean insertion torque and force measured from the self-tapping AT screw were not significantly different compared with the 4.5-mm AO tap. There were no significant differences in maximum screw torque among constructs. Total procedure time was significantly longer for the AT group (5.8 +/- 1.6 minutes) compared with the AO group (2.9 +/- 1.1 minutes; P =.001). AT stabilized specimens had significantly greater mean +/- SD initial shear stiffness (3.64 +/- 1.08 kN/mm) than AO specimens (1.64 +/- 0.73 kN/mm; P =.005). All other

  11. Enhancing the immersive reality of virtual simulators for easily accessible laparoscopic surgical training (United States)

    McKenna, Kyra; McMenemy, Karen; Ferguson, R. S.; Dick, Alistair; Potts, Stephen


    Computer simulators are a popular method of training surgeons in the techniques of laparoscopy. However, for the trainee to feel totally immersed in the process, the graphical display should be as lifelike as possible and two-handed force feedback interaction is required. This paper reports on how a compelling immersive experience can be delivered at low cost using commonly available hardware components. Three specific themes are brought together. Firstly, programmable shaders executing in standard PC graphics adapter's deliver the appearance of anatomical realism, including effects of: translucent tissue surfaces, semi-transparent membranes, multilayer image texturing and real-time shadowing. Secondly, relatively inexpensive 'off the shelf' force feedback devices contribute to a holistic immersive experience. The final element described is the custom software that brings these together with hierarchically organized and optimized polygonal models for abdominal anatomy.

  12. Three-dimensional planning and simulation of hip operations and computer-assisted construction of endoprostheses in bone tumor surgery. (United States)

    Handels, H; Ehrhardt, J; Plötz, W; Pöppl, S J


    This article presents the VIRTOPS (VIRTual Operation Planning in Orthopaedic Surgery) software system for virtual preoperative planning and simulation of hip operations. The system is applied to simulate the endoprosthetic reconstruction of the hip joint with hemipelvic replacement, and supports the individual design of anatomically adaptable, modular prostheses in bone tumor surgery. The virtual planning of the operation and the construction of the individual implant are supported by virtual reality techniques. The central step of the operation planning procedure, the placement of the cutting plane in the hip bone, depends strongly on the tumor's position. Segmentation of the tumor and the bones in MR and CT data, as well as fusion of MR and CT image sequences, is necessary to visualize the tumor's position within the hip bone. Three-dimensional models of the patient's hip are generated based on CT image data. A ROI-based segmentation algorithm enables the separation of the bone tumor in multispectral MR image sequences. A special registration method using segmentation results has been developed to transfer CT and MR data into one common coordinate system. During the 3D planning process, the surgeon simulates the operation and defines the position and geometry of the custom-made endoprosthesis. Stereoscopic visualization and 3D input devices facilitate navigation and 3D interaction in the virtual environment. Special visualization techniques such as texture mapping, color coding of quantitative parameters, and transparency support the determination of the correct position and geometry of the prosthesis. The VIRTOPS system enables the complete virtual planning of hip operations with endoprosthetic reconstruction, as well as the optimal placement and design of endoprostheses. After the registration and segmentation of CT and MR data, 3D visualizations of the tumor within the bone are generated to support the surgeon during the planning procedure. In the virtual

  13. Young's modulus and SEM analysis of leg bones exposed to simulated microgravity by hind limb suspension (HLS)

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Niravkumar D.; Mehta, Rahul [Department of Physics and Astronomy, University of Central Arkansas, 201 Donaghey Avenue, Lewis Science Center 171, Conway, AR 72035 (United States); Ali, Nawab [Department of Applied Science, University of Arkansas at Little Rock, 2801 S. University Avenue, Little Rock, AR 72204 (United States); Soulsby, Michael; Chowdhury, Parimal [Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR 72205 (United States)


    The aim of this study was to determine composition of the leg bone tissue of rats that were exposed to simulated microgravity by Hind-Limb Suspension (HLS) by tail for one week. The leg bones were cross sectioned, cleaned of soft tissues, dried and sputter coated, and then placed horizontally on the stage of a Scanning Electron Microscope (SEM) for analysis. Interaction of a 17.5 keV electron beam, incident from the vertical direction on the sample, generated images using two detectors. X-rays emitted from the sample during electron bombardment were measured with an Energy Dispersive Spectroscopy (EDS) feature of SEM using a liquid-nitrogen cooled Si(Li) detector with a resolution of 144 eV at 5.9 keV ({sub 25}Mn K{sub {alpha}} x-ray). K{sub {alpha}}- x-rays from carbon, oxygen, phosphorus and calcium formed the major peaks in the spectrum. Relative percentages of these elements were determined using a software that could also correct for ZAF factors namely Z(atomic number), A(X-ray absorption) and F(characteristic fluorescence). The x-rays from the control groups and from the experimental (HLS) groups were analyzed on well-defined parts (femur, tibia and knee) of the leg bone. The SEM analysis shows that there are definite changes in the hydroxyl or phosphate group of the main component of the bone structure, hydroxyapatite [Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}], due to hind limb suspension. In a separate experiment, entire leg bones (both from HLS and control rats) were subjected to mechanical stress by mean of a variable force. The stress vs. strain graph was fitted with linear and polynomial function, and the parameters reflecting the mechanical strength of the bone, under increasing stress, were calculated. From the slope of the linear part of the graph the Young's modulus for HLS bones were calculated and found to be 2.49 times smaller than those for control bones.

  14. Usefulness of Preoperative Surgical Simulation with Three-Dimensional Fusion Images for Resection of Cerebral Cavernous Malformations Near Broca’s Area

    Directory of Open Access Journals (Sweden)

    Satoshi Takahashi


    Full Text Available Treating subcortical brain lesions in or near eloquent areas is challenging not only because lesions must be resected while preserving brain tissue involved in essential functions, but also because lesions often cannot be easily identified from the surface of the brain. Here, we report 2 cases of cerebral cavernous malformations near Broca’s area. In both cases, lesions were surgically removed by utilizing three-dimensional fusion images created using preoperative magnetic resonance imaging and computed tomography data. Excisions were completed without any worsening of speech function, and the use of presurgical simulations was found to be useful in the design and execution of the actual operations. The technique described in this report serves as a useful tool in simulating surgical strategies by using brain gyri and sulci as surgical landmarks. Furthermore, in contrast to other intraoperative techniques, this method can aid in shortening the duration of surgery and can help limit damage to eloquent areas of the brain.

  15. See me, touch me, heal me : the role of visuo-spatial ability in virtual anatomical learning and surgical simulator training

    NARCIS (Netherlands)

    Luursema, J.M.


    Medical learning and training are fields in transition. Catalyst in this change is the introduction of digital technology, for example in the form of simulator technology in surgical training, and virtual learning environments in anatomical learning. The primary aim of this thesis is to help

  16. The salutary effect of dietary calcium on bone mass in a rat model of simulated weightlessness (United States)

    Bikle, D. D.; Globus, R.; Halloran, B. P.; Morey-Holton, E.


    Whether supplementation of dietary calcium reduces the differences in bone mass of unweighed limbs and normally weighted limbs, and whether parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D (1,25(OH)2D) respond differently to dietary calcium in unweighted animals in comparison with pair-fed controls was studied. The hind limbs of rats were unweighted by a tail suspension method and diets containing 0.1% to 2.4% calcium. After 2 weeks serum calcium, phosphorus, PTH and 1,25(OH)2D intestinal calcium transport were determined and bone mass, ash weight, and calcium in the tibia, L-1 vertebra, and humerus were measured. No significant differences in body weights were observed among the various groups. Suspended rats maintained constant levels of serum calcium and phosphate over the wide range of dietary calcium. Serum PTH and 1,25(OH)2D and intestinal calcium transport fell as dietary calcium was increased. Bone calcium in the tibia and vertebra from suspended rats remained less than that from pair-fed control. It is suggested that although no striking difference between suspended and control animals was observed in response to dieteary calcium, increasing dietary calcium may reduce the negative impact of unloading on the calcium content of the unweighted bones. The salutary effect of high dietary calcium appears to be due to inhibition of bone resorption rather than to stimulation of bone formation.

  17. Bone Marrow-Derived Mesenchymal Stromal Cells Enhanced by Platelet-Rich Plasma Maintain Adhesion to Scaffolds in Arthroscopic Simulation. (United States)

    Hoberman, Alexander R; Cirino, Carl; McCarthy, Mary Beth; Cote, Mark P; Pauzenberger, Leo; Beitzel, Knut; Mazzocca, Augustus D; Dyrna, Felix


    To assess the response of bone marrow-derived mesenchymal stromal cells (bMSCs) enhanced by platelet-rich plasma (PRP) in the setting of a normal human tendon (NHT), a demineralized bone matrix (DBM), and a fibrin scaffold (FS) with simulated arthroscopic mechanical washout stress. Bone marrow was aspirated from the humeral head and concentrated. BMSCs were counted, plated, and grown to confluence. Cells were seeded onto 3 different scaffolds: (1) NHT, (2) DBM, and (3) FS. Each scaffold was treated with a combination of (+)/(-) PRP and (+)/(-) arthroscopic washout simulation. A period of 60 minutes was allotted before arthroscopic washout. Adhesion, proliferation, and differentiation assays were performed to assess cellular activity in each condition. Significant differences were seen in mesenchymal stromal cell adhesion, proliferation, and differentiation among the scaffolds. DBM and FS showed superior results to NHT for cell adhesion, proliferation, and differentiation. PRP significantly enhanced cellular adhesion, proliferation, and differentiation. Arthroscopic simulation did not significantly decrease bMSC adhesion. We found that the type of scaffold impacts bMSCs' behavior. Both scaffolds (DBM and FS) were superior to NHT. The use of an arthroscopic simulator did not significantly decrease the adhesion of bMSCs to the scaffolds nor did it decrease their biologic differentiation potential. In addition, PRP enhanced cellular adhesion, proliferation, and differentiation. Improved healing after tendon repair can lead to better clinical outcomes. BMSCs are attractive for enhancing healing given their accessibility and regenerative potential. Application of bMSCs using scaffolds as cell carriers relies on arthroscopic feasibility. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  18. Validation, correlation, and comparison of the da Vinci trainer(™) and the daVinci surgical skills simulator(™) using the Mimic(™) software for urologic robotic surgical education. (United States)

    Liss, Michael A; Abdelshehid, Corollos; Quach, Stephen; Lusch, Achim; Graversen, Joseph; Landman, Jaime; McDougall, Elspeth M


    Virtual reality simulators with self-assessment software may assist novice robotic surgeons to augment direct proctoring in robotic surgical skill acquisition. We compare and correlate the da Vinci Trainer™ (dVT) and da Vinci Surgical Skills Simulators (dVSSS) in subjects with varying robotic experience. Students, urology residents, fellows, and practicing urologists with varying robotic experience were enrolled after local institutional review board approval. Three virtual reality tasks were preformed in sequential order (pegboard 1, pegboard 2, and tubes)-initially on the dVSSS and then on the dVT. The Mimic™ software used on both systems provides raw values and percent scores that were used in statistical evaluation. Statistical analysis was performed with the two-tailed independent t-test, analysis of variance, Tukey, and the Pearson rank correlation coefficient where appropriate. Thirty-two participants were recruited for this study and separated into five groups based on robotic surgery experience. In regards to construct validity, both simulators were able to differentiate differences among the five robotic surgery experience groups in the tubes suturing task (p≤0.00). Sixty-seven percent (4/6) robotic experts thought that surgical simulation should be implemented in residency training. The overall cohort considered both platforms easy to learn and use. Although performance scores were less in the dVT compared with the dVSSS, both simulators demonstrate good content and construct validity. The simulators appear to be equivalent for assessing surgeon proficiency and either can be used for robotic skills training with self-assessment feedback.

  19. Simulated change in body fatness affects Hologic QDR 4500A whole body and central DXA bone measures. (United States)

    Evans, Ellen M; Mojtahedi, Mina C; Kessinger, Renee B; Misic, Mark M


    Changes in body fatness may impact the accuracy of dual energy X-ray absorptiometry (DXA) measures of bone mineral content (BMC) and bone mineral density (BMD). The aim of this study was to determine if DXA can accurately assess BMC and BMD with changes in exogenous fat (lard) placed to simulate weight change. Whole body (WB), lumbar spine (LS), and proximal femur (PF) DXA scans (Hologic QDR 4500A) were performed on 30 elderly (52-83 yr) and 60 young (18-40 yr) individuals (i.e., 45 females and 45 males) of varying body mass index (mean+/-standard deviation: 26.1+/-4.9 kg/m2). When scans were repeated with lard packets (2.54 cm thick, 25.4x17.8 cm, 1 kg), WB BMD decreased 1.1% and 1.6% after chest and thigh packet placement, respectively (p=0.001), PF BMD increased 0.7% (p=0.02) and LS BMD decreased 1.6% (p=0.001) primarily due to a 2.2% reduction in LS BMC (p<0.001). Initial LS BMC and trunk mass were related to error in LS BMC measures due to lard-loading (r=0.64 and 0.45, respectively, p<0.001). We conclude that on average simulated weight change minimally impacts PF bone measures and moderately impacts WB and LS bone measures; however, individual variability in measurement error was noteworthy and may be impacted by body thickness.

  20. Cadaveric Temporal Bone Dissection: Is It Obsolete Today?

    Directory of Open Access Journals (Sweden)

    Naik, Sulabha M.


    Full Text Available Introduction Traditionally, surgical training in otology, is imparted by dissecting harvested human cadaveric temporal bones. However, maintenance of a cadaveric temporal bone laboratory is expensive and carries risk of exposure to infection. In recent times, other modalities of training are gaining ground and are likely to eventually replace cadaveric temporal bone dissection altogether. Objectives Other alternative methods of training are emerging. New technology like simulation and virtual reality as high-fidelity, safer alternatives, are making rapid strides as teaching tools. Other options are the use of animal temporal bones as teaching tools. The advantages of these are compared. Data Synthesis None of these modalities can replicate the innumerable anatomical variations which are a characteristic feature of the human temporal bone. A novice surgeon not only needs exposure to surgical anatomy and it's variations but also needs to develop hand-eye coordination skills to gain expertise. Conclusion Deliberate practice on human cadaveric temporal bones only, will confer both mastery in anatomy and surgical technique. The human cadaveric temporal bone is ideal simulator for training in otology.

  1. Numerical simulation of fluid field and in vitro three-dimensional fabrication of tissue-engineered bones in a rotating bioreactor and in vivo implantation for repairing segmental bone defects. (United States)

    Song, Kedong; Wang, Hai; Zhang, Bowen; Lim, Mayasari; Liu, Yingchao; Liu, Tianqing


    In this paper, two-dimensional flow field simulation was conducted to determine shear stresses and velocity profiles for bone tissue engineering in a rotating wall vessel bioreactor (RWVB). In addition, in vitro three-dimensional fabrication of tissue-engineered bones was carried out in optimized bioreactor conditions, and in vivo implantation using fabricated bones was performed for segmental bone defects of Zelanian rabbits. The distribution of dynamic pressure, total pressure, shear stress, and velocity within the culture chamber was calculated for different scaffold locations. According to the simulation results, the dynamic pressure, velocity, and shear stress around the surface of cell-scaffold construction periodically changed at different locations of the RWVB, which could result in periodical stress stimulation for fabricated tissue constructs. However, overall shear stresses were relatively low, and the fluid velocities were uniform in the bioreactor. Our in vitro experiments showed that the number of cells cultured in the RWVB was five times higher than those cultured in a T-flask. The tissue-engineered bones grew very well in the RWVB. This study demonstrates that stress stimulation in an RWVB can be beneficial for cell/bio-derived bone constructs fabricated in an RWVB, with an application for repairing segmental bone defects.

  2. Biomechanical analysis of pedicle screws in osteoporotic bone with bioactive cement augmentation using simulated in vivo multicomponent loading. (United States)

    Choma, Theodore J; Frevert, Wesley F; Carson, William L; Waters, Nicole P; Pfeiffer, Ferris M


    Biomechanical analysis of bioactive cements augmenting pedicle screw resistance to loosening in osteoporotic synthetic bone. To simulate in vivo loading-loosening of pedicle screws in osteoporotic vertebrae; and to compare biomechanical efficacy of the following bioactive cements: calcium phosphate (CP), calcium sulfate (CS), and proprietary mixture (M). Pedicle screw instrumentation in osteoporotic spines is limited by poor bone-screw interface strength, resulting in screw loosening fixation failure. Previous in vivo studies evaluated augmented pedicle screw resistance to pure pullout, not simulating in vivo loading/failure. A pedicle screw-instrumented osteoporotic thoracic vertebra subjected to combined pullout, transverse, moment loading was simulated. Unconstrained 3-dimensional screw motion relative to vertebra was optically measured during quasi-static, and dynamic loading. Augmented groups (CP, CS, M) produced (P CS > M failure initiation force (P < 0.006) was because of differences in cement distribution. Animal studies may be required to characterize the remodeling activity of bioactive cements and their longer term efficacies.

  3. Measured and Monte Carlo simulated surface dose reduction for superficial X-rays incident on tissue with underlying air or bone. (United States)

    Baines, John; Zawlodzka, Sylwia; Markwell, Tim; Chan, Millicent


    Measurement of surface dose reduction effects for superficial x-rays incident on tissue with underlying air or bone and comparison with Monte Carlo simulations of such effects. Further to investigate the correlation between surface dose reduction and changes in Compton backscatter spectra with tissue-bone separation. An Advanced Markus chamber with entrance window facing downstream on the surface of a solid water phantom was used to investigate changes in surface dose with an underlying air or bone interface located at various depths below the surface. Chamber readings were obtained for interface depths ranging from 1 to 100 mm using the 50 kV, 100 kV and 150 kV beams of an Xstrahl 150 x-ray unit, with field diameters (ϕ) = 2.5 cm and 5 cm. For each beam quality and field size the dose correction factor, DCF(t), namely the ratio of measured dose (t) to dose (t = 100 mm) was determined. Monte Carlo simulations of DCF(t) for air and bone interfaces in tissue are used to validate corresponding measured data. For a given beam and field size, the difference between simulated spectra with an air or bone interface at t = 3 mm was used to determine the Compton backscatter from bone at the surface. For air, DCF(t tube potentials corresponding factors, ϕ = 2.5 cm, for air(bone) are 0.94(0.96) and 0.92(0.99). Calculated DCF(t) based on Monte Carlo simulations are consistent with experimental observations to within 2%. Monte Carlo simulations of x-ray spectra demonstrate the presence of Compton backscatter from underlying bone in tissue. With bone at 3 mm depth calculated backscatter spectra at the tissue surface suggest that surface dose is influenced by the proximity of bone and that this effect depends on beam quality. This work demonstrates the feasibility of using an Advanced Markus chamber with entrance window facing downstream to investigate surface dose reduction with underlying air or bone in tissue. As the field size decreases and beam quality increases surface

  4. A Massive Chondroblastoma in the Proximal Humerus Simulating Malignant Bone Tumors

    Directory of Open Access Journals (Sweden)

    Ichiro Tonogai


    Full Text Available Chondroblastoma is a mostly benign bone neoplasm that typically affects the second decade of life and exhibits a lytic lesion in the epiphysis of long bones. We report an extreme case of massive, destructive chondroblastoma of the proximal humerus in a 9-year-old girl. It was difficult to differentiate using imaging information the lesion from malignant bone tumors such as osteosarcoma. Histopathological examination from biopsy proved chondroblastoma. The tumor was resected after preoperative transcatheter embolization. Reconstructive procedure for the proximal humerus was not performed due to the local destruction. The present case demonstrates clinical and radiological differentiations of the massive chondroblastoma from the other lesions and histopathological understandings for this lesion.

  5. Detection of Simulated Periodontal Bone Defects Using Digital Images. An in vitro Study

    Directory of Open Access Journals (Sweden)

    Rafael Scaf de Molon


    Materials and Methods: The samples comprised 24 hemi-mandibles from pigs, which were allocated into 3 groups; G1 (before acid application, G2 (after acid application and G3 (without bone defect and acid treatment. Periodontal bone defects were created with round burs between the second and third pre-molar. The radiographs were taken using the Visualix eHD sensor. The central ray was perpendicular to the sensor and to the hemi-mandible at a 40 cm focal-spot to sensor distance (settings 70 kVp, 10 mA and 15 impulses. After the defects were created in groups G1 and G2, they were treated with 100% perchloric acid for 48 hours. Images were zoomed to the level of 125% and interpreted by three examiners. Sensitivity and specificity were computed for the detection of periodontal bone defects with acid application and created using only round burs. The examiner's radiographic interpretation produced a diagnosis based on a five-point confidence scale. If the interpretation received the scores 1 or 2, it was concluded that no bone defect was present, whereas the scores 3, 4, or 5 were considered to reflect evidence of a bone defect. Results: There was no difference between groups G1 (Sen -95%CI=0.9167; Spec -95%CI=0.9167 and G2 (Sen -95%CI=0.8333; Spec -95%CI=0.9167. Conclusions: There is no difference in the detection of periodontal bone defects created using round burs and defects created using round burs followed by acid treatment. [Arch Clin Exp Surg 2014; 3(4.000: 220-225

  6. Comparison of autologous bone marrow and adipose tissue derived mesenchymal stem cells, and platelet rich plasma, for treating surgically induced lesions of the equine superficial digital flexor tendon. (United States)

    Romero, A; Barrachina, L; Ranera, B; Remacha, A R; Moreno, B; de Blas, I; Sanz, A; Vázquez, F J; Vitoria, A; Junquera, C; Zaragoza, P; Rodellar, C


    Several therapies have been investigated for equine tendinopathies, but satisfactory long term results have not been achieved consistently and a better understanding of the healing mechanism elicited by regenerative therapies is needed. The aim of this study was to assess the separate effects of autologous bone marrow (BM) and adipose tissue (AT) derived mesenchymal stem cells (MSCs), and platelet rich plasma (PRP), for treating lesions induced in the superficial digital flexor tendon (SDFT) of horses. Lesions were created surgically in both SDFTs of the forelimbs of 12 horses and were treated with BM-MSCs (six tendons), AT-MSCs (six tendons) or PRP (six tendons). The remaining six tendons received lactated Ringer's solution as control. Serial ultrasound assessment was performed prior to treatment and at 2, 6, 10, 20 and 45 weeks post-treatment. At 45 weeks, histopathology and gene expression analyses were performed. At week 6, the ultrasound echogenicity score in tendons treated with BM-MSCs suggested earlier improvement, whilst all treatment groups reached the same level at week 10, which was superior to the control group. Collagen orientation scores on histological examination suggested a better outcome in treated tendons. Gene expression was indicative of better tissue regeneration after all treatments, especially for BM-MSCs, as suggested by upregulation of collagen type I, decorin, tenascin and matrix metalloproteinase III mRNA. Considering all findings, a clear beneficial effect was elicited by all treatments compared with the control group. Although differences between treatments were relatively small, BM-MSCs resulted in a better outcome than PRP and AT-MSCs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Simulation of the mechanical behavior of a HIP implant. Implant fixed to bone by cementation under arbitrary load (United States)

    Oldani, C. R.; Dominguez, A. A.


    In a previous work a finite elements model was constructed to simulate a fatigue assay according to the norm IRAM 9422-3. Three materials were studied, two of them are the most used in this type of implant (Stainless steel 3161 and alloy T16A14V) and the third was a new developed titanium alloy (Ti35Nb7Zr5Ta). Static loads were applied to the model according to the highest requirements of the norm and the stress - strain distribution were determined. In this study a simplified analysis of the material's fatigue was done according to the previous work. The best behavior of the titanium alloys vs. the stainless steel was evident. With the objective of studying the behavior of both: the implant and the femur bone, new finite elements models were realized, in which the presence of the bone was considered. Inside the bone, the femoral component of the implant was placed in a similar way of a cemented prosthesis in a total hip arthroplasty. The advantage of the titanium implant related to the stainless steel one, was very clear.

  8. Simulation of the mechanical behavior of a HIP implant. Implant fixed to bone by cementation under arbitrary load

    Energy Technology Data Exchange (ETDEWEB)

    Oldani, C R [Materials Department - FCEFyN - Universidad Nacional de Cordoba, Av.Velez Sarsfield 1611 (5016) Cordoba (Argentina); Dominguez, A A [INTI Cordoba, Av. Velez Sarsfield 1561 (5016) Cordoba (Argentina)


    In a previous work a finite elements model was constructed to simulate a fatigue assay according to the norm IRAM 9422-3. Three materials were studied, two of them are the most used in this type of implant (Stainless steel 3161 and alloy T16A14V) and the third was a new developed titanium alloy (Ti35Nb7Zr5Ta). Static loads were applied to the model according to the highest requirements of the norm and the stress - strain distribution were determined. In this study a simplified analysis of the material's fatigue was done according to the previous work. The best behavior of the titanium alloys vs. the stainless steel was evident. With the objective of studying the behavior of both: the implant and the femur bone, new finite elements models were realized, in which the presence of the bone was considered. Inside the bone, the femoral component of the implant was placed in a similar way of a cemented prosthesis in a total hip arthroplasty. The advantage of the titanium implant related to the stainless steel one, was very clear.

  9. Insertion Torques of Self-Drilling Mini-Implants in Simulated Mandibular Bone: Assessment of Potential for Implant Fracture. (United States)

    Hosein, Yara K; Smith, Angie; Dunning, Cynthia E; Tassi, Ali


    Fracture of orthodontic mini-implants during insertion is a limiting factor for their clinical success. The purpose of this study was to determine the fracture potential of commonly used self-drilling orthodontic mini-implants when placed into simulated thick, dense mandibular bone. Six mini-implant systems were assessed for the potential for fracture (Aarhus, Medicon; Dual-Top, Jeil Medical; OrthoEasy, Forestadent; tomas-pin, Dentaurum; Unitek, 3M; and VectorTAS, Ormco). First, mini-implants were inserted manually, without predrilling, into bone substitutes (Sawbones) with a 3-mm-thick, dense (1.64 g/cm(3)) cortical layer. A custom-made insertion device was used for placement of mini-implants. A sixaxis force/torque transducer was secured at the base of the bone blocks to measure the maximum torque experienced during insertion. Measured insertion torques were compared with previously reported fracture torques, yielding a torque ratio (insertion torque as a percentage of fracture torque), which was used as an indicator of the potential for mini-implant fracture. Mini-implants that experienced torque ratios ≥ 75% upon insertion underwent further testing, following the manufacturer's recommendations for predrilling in thick, dense bone conditions. Significant differences in torque ratios were found among all mini-implants, except between OrthoEasy and Dual-Top, and OrthoEasy and VectorTAS. Overall, Aarhus had the highest torque ratio (91% ± 3%), with Unitek showing the lowest ratio (37% ± 3%). Aarhus and tomas-pin mini-implants displayed torque ratios ≥ 75% and experienced fracture upon insertion. When the manufacturer's specific predrilling recommendations were followed, no changes in torque ratio were found for Aarhus and tomas-pin. However, while Aarhus continued to fracture upon insertion, all tomas-pin mini-implants were inserted fully without fracture following predrilling. These findings support the safe use of Unitek, VectorTAS, Dual-Top, and Ortho

  10. A new constitutive model for simulation of softening, plateau, and densification phenomena for trabecular bone under compression. (United States)

    Lee, Chi-Seung; Lee, Jae-Myung; Youn, BuHyun; Kim, Hyung-Sik; Shin, Jong Ki; Goh, Tae Sik; Lee, Jung Sub


    A new type of constitutive model and its computational implementation procedure for the simulation of a trabecular bone are proposed in the present study. A yield surface-independent Frank-Brockman elasto-viscoplastic model is introduced to express the nonlinear material behavior such as softening beyond yield point, plateau, and densification under compressive loads. In particular, the hardening- and softening-dominant material functions are introduced and adopted in the plastic multiplier to describe each nonlinear material behavior separately. In addition, the elasto-viscoplastic model is transformed into an implicit type discrete model, and is programmed as a user-defined material subroutine in commercial finite element analysis code. In particular, the consistent tangent modulus method is proposed to improve the computational convergence and to save computational time during finite element analysis. Through the developed material library, the nonlinear stress-strain relationship is analyzed qualitatively and quantitatively, and the simulation results are compared with the results of compression test on the trabecular bone to validate the proposed constitutive model, computational method, and material library. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Modeling soft-tissue deformation prior to cutting for surgical simulation: finite element analysis and study of cutting parameters. (United States)

    Chanthasopeephan, Teeranoot; Desai, Jaydev P; Lau, Alan C W


    This paper presents an experimental study to understand the localized soft-tissue deformation phase immediately preceding crack growth as observed during the cutting of soft tissue. Such understanding serves as a building block to enable realistic haptic display in simulation of soft tissue cutting for surgical training. Experiments were conducted for soft tissue cutting with a scalpel blade while monitoring the cutting forces and blade displacement for various cutting speeds and cutting angles. The measured force-displacement curves in all the experiments of scalpel cutting of pig liver sample having a natural bulge in thickness exhibited a characteristic pattern: repeating units formed by a segment of linear loading (deformation) followed by a segment of sudden unloading (localized crack extension in the tissue). During the deformation phase immediately preceding crack extension in the tissue, the deformation resistance of the soft tissue was characterized with the local effective modulus (LEM). By iteratively solving an inverse problem formulated with the experimental data and finite element models, this measure of effective deformation resistance was determined. Then computational experiments of model order reduction were conducted to seek the most computationally efficient model that still retained fidelity. Starting with a 3-D finite element model of the liver specimen, three levels of model order reduction were carried out with computational effort in the ratio of 1.000:0.103:0.038. We also conducted parametric studies to understand the effect of cutting speed and cutting angle on LEM. Results showed that for a given cutting speed, the deformation resistance decreased as the cutting angle was varied from 90 degrees to 45 degrees. For a given cutting angle, the deformation resistance decreased with increase in cutting speed.

  12. The Impact of Simulated and Real Microgravity on Bone Cells and Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Claudia Ulbrich


    machine (RPM, the 2D-clinostat, or the NASA-developed rotating wall vessel bioreactor (RWV to create tissue from bone, tumor, and mesenchymal stem cells. To understand the development of 3D structures, in vitro experiments using s-µg devices can provide valuable information about modulations in signal-transduction, cell adhesion, or extracellular matrix induced by altered gravity conditions. These systems also facilitate the analysis of the impact of growth factors, hormones, or drugs on these tissue-like constructs. Progress has been made in bone tissue engineering using the RWV, and multicellular tumor spheroids (MCTS, formed in both r- and s-µg, have been reported and were analyzed in depth. Currently, these MCTS are available for drug testing and proteomic investigations. This review provides an overview of the influence of µg on the aforementioned cells and an outlook for future perspectives in tissue engineering.

  13. Use of 3-dimensional printing technology and silicone modeling in surgical simulation: development and face validation in pediatric laparoscopic pyeloplasty. (United States)

    Cheung, Carling L; Looi, Thomas; Lendvay, Thomas S; Drake, James M; Farhat, Walid A


    Pediatric laparoscopy poses unique training challenges owing to smaller workspaces, finer sutures used, and potentially more delicate tissues that require increased surgical dexterity when compared with adult analogs. We describe the development and face validation of a pediatric pyeloplasty simulator using a low-cost laparoscopic dry-laboratory model developed with 3-dimensional (3D) printing and silicone modeling. The organs (the kidney, renal pelvis, and ureter) were created in a 3-step process where molds were created with 3D modeling software, printed with a Spectrum Z510 3D printer, and cast with Dragon Skin 30 silicone rubber. The model was secured in a laparoscopy box trainer. A pilot study was conducted at a Canadian Urological Association meeting. A total of 24 pediatric urology fellows and 3 experienced faculty members then assessed our skills module during a minimally invasive surgery training course. Participants had 60 minutes to perform a right-side pyeloplasty using laparoscopic tools and 5-0 VICRYL suture. Face validity was demonstrated on a 5-point Likert scale. The dry-laboratory model consists of a kidney, a replaceable dilated renal pelvis and ureter with an obstructed ureteropelvic junction, and an overlying peritoneum with an inscribed fundamentals of laparoscopic surgery pattern-cutting exercise. During initial validation at the Canadian Urological Association, participants rated (out of 5) 4.75 ± 0.29 for overall impression, 4.50 ± 0.41 for realism, and 4.38 ± 0.48 for handling. During the minimally invasive surgery course, 22 of 24 fellows and all the faculty members completed the scoring. Usability was rated 4 or 5 by 14 participants (overall, 3.6 ± 1.22 by novices and 3.7 ± 0.58 by experts), indicating that they would use the model in their own training and teaching. Esthetically, the model was rated 3.5 ± 0.74 (novices) and 3.3 ± 0.58 (experts). We developed a pediatric pyeloplasty simulator by applying a low-cost reusable model

  14. Surgical tips of intramedullary nailing in severely bowed femurs in atypical femur fractures: Simulation with 3D printed model. (United States)

    Park, Jai Hyung; Lee, Yongkoo; Shon, Oog-Jin; Shon, Hyun Chul; Kim, Ji Wan


    The surgical management of atypical femoral fractures (AFFs) is complex in cases with severe bowing of the femur, being associated with a high rate of failure. Our first aim was to use preoperative templating and 3D printed model characterise the technical difficulties associated with use of current commercially available intramedullary nail (IMN) systems for the management of AFFs with severe bowing. Our second aim was to use outcomes of our 3D printing analysis to define technical criteria to overcome these problems. The modelled femur with 3D printing had an anterior bowing curvature radius of 772mm and an angle of lateral bowing of 15.4°. Nine commercially available IMN systems were evaluated in terms of position of the nail within the medullary canal, occurrence of perforation of femoral cortex by the distal tip of the nail, and location of the site of perforation relative to the knee joint. The following IMN systems were evaluated: unreamed femoral nail (UFN), cannulated femoral nail (CFN), Sirus nail, right and left expert Asian femoral nail (A2FN), right and left Zimmer Natural Nail (ZNN), proximal femoral nail anti-rotation (PFNA), and Zimmer Cephalomedullary Nail (CMN). Along the sagittal plane, the UFN, CFN and Sirus systems were acceptably contained within the medullary canal, as well as the "opposite side" A2FN and ZNN. Only the Sirus IMN system was contained along the coronal plane. The distal part of the all other IMN systems perforated the anterior cortex of the femur, at distances ranging between 2.8 and 11.7cm above the distal end of the femoral condyles. Using simulated fracture reduction in the 3D printed model, none of the 9 IMN systems provided acceptable anatomical reduction of the fracture. A residual gap in fragment position and translation was provided by the "opposite side" ZNN, followed by the UFN and Sirus systems. Commercially available IMN systems showed mismatch with severely bowed femurs. Our simulation supports that fit of these

  15. Micro-scale finite element modeling of ultrasound propagation in aluminum trabecular bone-mimicking phantoms: A comparison between numerical simulation and experimental results. (United States)

    Vafaeian, B; Le, L H; Tran, T N H T; El-Rich, M; El-Bialy, T; Adeeb, S


    The present study investigated the accuracy of micro-scale finite element modeling for simulating broadband ultrasound propagation in water-saturated trabecular bone-mimicking phantoms. To this end, five commercially manufactured aluminum foam samples as trabecular bone-mimicking phantoms were utilized for ultrasonic immersion through-transmission experiments. Based on micro-computed tomography images of the same physical samples, three-dimensional high-resolution computational samples were generated to be implemented in the micro-scale finite element models. The finite element models employed the standard Galerkin finite element method (FEM) in time domain to simulate the ultrasonic experiments. The numerical simulations did not include energy dissipative mechanisms of ultrasonic attenuation; however, they expectedly simulated reflection, refraction, scattering, and wave mode conversion. The accuracy of the finite element simulations were evaluated by comparing the simulated ultrasonic attenuation and velocity with the experimental data. The maximum and the average relative errors between the experimental and simulated attenuation coefficients in the frequency range of 0.6-1.4 MHz were 17% and 6% respectively. Moreover, the simulations closely predicted the time-of-flight based velocities and the phase velocities of ultrasound with maximum relative errors of 20 m/s and 11 m/s respectively. The results of this study strongly suggest that micro-scale finite element modeling can effectively simulate broadband ultrasound propagation in water-saturated trabecular bone-mimicking structures. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Cortical bone trajectory screw fixation versus traditional pedicle screw fixation for 2-level posterior lumbar interbody fusion: comparison of surgical outcomes for 2-level degenerative lumbar spondylolisthesis. (United States)

    Sakaura, Hironobu; Miwa, Toshitada; Yamashita, Tomoya; Kuroda, Yusuke; Ohwada, Tetsuo


    OBJECTIVE The cortical bone trajectory (CBT) screw technique is a new nontraditional pedicle screw (PS) insertion method. However, the biomechanical behavior of multilevel CBT screw/rod fixation remains unclear, and surgical outcomes in patients after 2-level posterior lumbar interbody fusion (PLIF) using CBT screw fixation have not been reported. Thus, the purposes of this study were to examine the clinical and radiological outcomes after 2-level PLIF using CBT screw fixation for 2-level degenerative lumbar spondylolisthesis (DS) and to compare these outcomes with those after 2-level PLIF using traditional PS fixation. METHODS The study included 22 consecutively treated patients who underwent 2-level PLIF with CBT screw fixation for 2-level DS (CBT group, mean follow-up 39 months) and a historical control group of 20 consecutively treated patients who underwent 2-level PLIF using traditional PS fixation for 2-level DS (PS group, mean follow-up 35 months). Clinical symptoms were evaluated using the Japanese Orthopaedic Association (JOA) scoring system. Bony union was assessed by dynamic plain radiographs and CT images. Surgery-related complications, including symptomatic adjacent-segment disease (ASD), were examined. RESULTS The mean operative duration and intraoperative blood loss were 192 minutes and 495 ml in the CBT group and 218 minutes and 612 ml in the PS group, respectively (p 0.05, respectively). The mean JOA score improved significantly from 12.3 points before surgery to 21.1 points (mean recovery rate 54.4%) at the latest follow-up in the CBT group and from 12.8 points before surgery to 20.4 points (mean recovery rate 51.8%) at the latest follow-up in the PS group (p > 0.05). Solid bony union was achieved at 90.9% of segments in the CBT group and 95.0% of segments in the PS group (p > 0.05). Symptomatic ASD developed in 2 patients in the CBT group (9.1%) and 4 patients in the PS group (20.0%, p > 0.05). CONCLUSIONS Two-level PLIF with CBT screw fixation

  17. Abortion - surgical (United States)

    Suction curettage; Surgical abortion; Elective abortion - surgical; Therapeutic abortion - surgical ... Surgical abortion involves dilating the opening to the uterus (cervix) and placing a small suction tube into the uterus. ...

  18. Simple and surgical exodontia. (United States)

    DeBowes, Linda J


    Preemptive and postoperative pain management is part of patient care when performing extractions. Simple extractions can become complicated when tooth roots are fractured. Adequate lighting,magnification, and surgical techniques are important when per-forming surgical (complicated) extractions. Radiographs should be taken before extractions and also during the procedure to assist with difficult extractions. Adequate flap design and bone removal are necessary when performing surgical extractions. Complications, including ocular trauma, jaw fracture, and soft tissue trauma, are avoided or minimized with proper patient selection and technique.

  19. Novel bone surrogates for cranial surgery training. (United States)

    Hollensteiner, Marianne; Fürst, David; Esterer, Benjamin; Augat, Peter; Schrödl, Falk; Hunger, Stefan; Malek, Michael; Stephan, Daniel; Schrempf, Andreas


    Parietal graft lifts are trained on human or animal specimens or are directly performed on patients without extensive training. In order to prevent harm to the patient resulting from fast rotating machinery tools, the surgeon needs to apply appropriate forces. Realistic haptics are essential to identify the varying parietal bone layers and to avoid a penetration of the brain. This however, requires experience and training. Therefore, in this study, bone surrogate materials were evaluated with the aim to provide an anatomically correct artificial skull cap with realistic haptic feedback for graft lift training procedures. Polyurethane composites made of calcium carbonate and calcium phosphate were developed and were used to create customized bone surrogates, imitating both cancellous and cortical bone. Mechanical properties of these surrogates were validated for drilling, milling and sawing by comparison with human parietal bones. For that, surgical tool tips were automatically inserted into artificial and human bones in a customized test bench and the maximum axial insertion forces were analyzed. Axial tool insertion measurements in human parietal bones resulted in mean maximum forces of 1.8±0.5N for drilling, 1.7±0.3N for milling and 0.9±0.1N for sawing. Calcium carbonate-based materials achieved higher forces than the human bone for drilling and milling, and lower forces for sawing. The calcium phosphate-based bone surrogates showed comparable axial insertions forces for all investigated tools and were identified as a suitable surrogate for drilling (p=0.87 and 0.41), milling (p=0.92 and 0.63) and sawing (p=0.11 and 0.76) of the cortical layer and the cancellous bone, respectively. In conclusion, our findings suggest, that a suitable material composition for artificial parietal bones has been identified, mimicking the properties of human bone during surgical machinery procedures. Thus, these materials are suitable for surgical training and education in

  20. Papercraft temporal bone in the first step of anatomy education. (United States)

    Hiraumi, Harukazu; Sato, Hiroaki; Ito, Juichi


    (1) To compare temporal bone anatomy comprehension taught to speech therapy students with or without a papercraft model. (2) To explore the effect of papercraft simulation on the understanding of surgical approaches in first-year residents. (1) One-hundred and ten speech therapy students were divided into three classes. The first class was taught with a lecture only. The students in the second class were given a lecture and a papercraft modeling task without instruction. The third class modeled a papercraft with instruction after the lecture. The students were tested on their understanding of temporal bone anatomy. (2) A questionnaire on the understanding of surgical approaches was completed by 10 residents before and after the papercraft modeling. The papercraft models were cut with scissors to simulate surgical approaches. (1) The average scores were 4.4/8 for the first class, 4.3/8 for the second class, and 6.3/8 for the third class. The third class had significantly better results than the other classes (panatomy using a papercraft temporal bone model is effective in the first step of learning temporal bone anatomy and surgical approaches. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. A paradigm shift in surgical planning and simulation using 3Dgraphy: Experience of first 50 surgeries done using 3D-printed biomodels. (United States)

    Bagaria, Vaibhav; Chaudhary, Kshitij


    Preoperative planning is an important aspect of any orthopedic surgery. Traditionally, surgeons mentally rehearse the operation and anticipate problems based on data available from "radiography" like MRI and CT. 3D printed bio-models and tools, or "3Dgraphy" can simplify this mental exercise and provide a realistic and user-friendly portrayal of this radiographic data. Five surgeons participated in this multicenter study. 3D printed biomodels were obtained for 50 surgical cases that included periarticular trauma (24), pelvic trauma (11), complex primary (7), and revision arthroplasty (8). CT scan data was used to generate computer models which were then 3D printed in real size. These models were used to understand pathoanatomy and conduct simulated surgery as a part of preoperative planning. The models were sterilized and were used for intraoperative referencing. Following each case, the operating surgeon was asked to fill out a structured questionnaire to report on the perceived benefits of these tools. All surgeons reported that the biomodels provided additional information to conventional imaging that enhanced their knowledge of the complex pathoanatomy. It was useful in preoperative planning, rehearsing the operation, surgical simulation, intraoperative referencing, surgical navigation, preoperative implant selection, and inventory management. This probably reduced surgical time and improved accuracy of the surgery. All surgeons reported that they would not only use it themselves but also recommend it to other surgeons. 3Dgraphy was found to be a valuable tool in orthopedic surgeries that involve complex pathoanatomy like pelvic trauma, revision arthroplasty, and periarticular fracture. As the technology evolves and improves, they are likely to become a standard component of many orthopedic procedures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Simulated increased soft tissue thickness artefactually decreases trabecular bone score: a phantom study. (United States)

    Amnuaywattakorn, Sasithorn; Sritara, Chanika; Utamakul, Chirawat; Chamroonrat, Wichana; Kositwattanarerk, Arpakorn; Thamnirat, Kanungnij; Ongphiphadhanakul, Boonsong


    Trabecular bone score (TBS), which has been proposed to be used in complementary with bone mineral density (BMD) to improve the assessment of fracture risk, is negatively associated with body mass index (BMI). The effect of soft tissue, which is expected to be thicker in subjects with high BMI, on TBS was studied using three scan types: Hologic with fast array mode (Hfa), Hologic with high definition mode (Hhd), and GE-Lunar iDXA. A spine phantom provided by Hologic for routine quality control procedure was scanned using three scan types: Hfa, Hhd, and iDXA. The phantom was scanned with an overlying soft tissue equivalent material (bolus used in radiotherapy) of 0 (without), 1, 2.5, 3.5, 5 and 7.5 cm thick. For each setting, 30 acquisitions were performed in the same way as for the quality control procedure. TBS was calculated using TBS iNsight® software version 2.1 on the same regions of interest as those used for lumbar spine BMD. Mean ± SD TBS of the phantom (without overlying soft tissue) were 1.379 ± 0.018, 1.430 ± 0.009, and 1.423 ± 0.005 using Hfa, Hhd, and iDXA, respectively. A one-way repeated measures ANOVA showed that there were statistically differences in TBS due to different thicknesses of soft tissue equivalent materials for all three scan types (p < 0.001). A Tukey post-hoc test revealed that the decrease in TBS was statistically significant (p < 0.001) when the soft tissue thickness was 1 cm (-0.0246 ± 0.0044, -0.0319 ± 0.0036, and -0.0552 ± 0.0015 for Hfa, Hhd, and iDXA, respectively). Although to a lesser degree, the effects were also statistically significant for BMD (p < 0.05): an increase for Hfa and Hhd but a decrease for iDXA. However, these changes did not exceed the least significant change (LSC) derived from patients. Increased soft tissue thickness results in lower TBS value. Although BMD is also affected, it is unlikely to pose a clinical problem because the change is unlikely to exceed

  3. Computer aided planning of orthopaedic surgeries: the definition of generic planning steps for bone removal procedures. (United States)

    Putzer, David; Moctezuma, Jose Luis; Nogler, Michael


    An increasing number of orthopaedic surgeons are using computer aided planning tools for bone removal applications. The aim of the study was to consolidate a set of generic functions to be used for a 3D computer assisted planning or simulation. A limited subset of 30 surgical procedures was analyzed and verified in 243 surgical procedures of a surgical atlas. Fourteen generic functions to be used in 3D computer assisted planning and simulations were extracted. Our results showed that the average procedure comprises 14 ± 10 (SD) steps with ten different generic planning steps and four generic bone removal steps. In conclusion, the study shows that with a limited number of 14 planning functions it is possible to perform 243 surgical procedures out of Campbell's Operative Orthopedics atlas. The results may be used as a basis for versatile generic intraoperative planning software.

  4. Simulated bone metastases: a case study of two patients with breast cancer

    International Nuclear Information System (INIS)

    Ainslie, J.; Drummond, R.; Blakey, D.; Bishop, M.; Hicks, R.; McKenzie, A.


    Two case studies are used to discuss topical issues current in follow-up management of patients with early stage breast cancer. These issues include the role of screening and diagnostic bone scintigraphy and patient self-advocacy in clinical management. Breast cancer is common. Standard clinical practice in Australia for patients treated for early stage carcinoma of the breast is regular follow-up, usually lasting 5 years, and often 10 years. There are numerous benefits for patients receiving regular clinical checkups post-treatment of breast cancer. However, the three prime objectives are early detection of recurrence, assessment of treatment-related morbidity, and provision of psychological support. Not surprisingly, a variety of intercurrent clinical events can occur in a population of post-treatment breast cancer patients on long-term follow-up. In this article we describe two interesting cases, each presenting with a solitary new destructive rib lesion highly suggestive of a first clinical diagnosis of metastatic breast cancer. Subsequent biopsy revealed the lesions to be benign. Copyright (1999) Blackwell Science Pty Ltd

  5. Effect of Alendronate with β - TCP Bone Substitute in Surgical Therapy of Periodontal Intra-Osseous Defects: A Randomized Controlled Clinical Trial. (United States)

    Naineni, Rohini; Ravi, Vishali; Subbaraya, Dwijendra Kocherlakota; Prasanna, Jammula Surya; Panthula, Veerendranath Reddy; Koduganti, Rekha Rani


    Alendronate (ALN), an aminobisphosphonate, inhibits osteoclastic bone resorption and also stimulates osteogenesis. Beta-Tricalcium Phosphate (β-TCP) is an osteoconductive graft material which provides a scaffold for bone formation and also a widely used drug delivery vehicle for growth factors and antibiotics. Drug delivery vehicles, like β-TCP, improve the potency of the drugs by specific local site delivery of the drug, optimal release characteristics and easy handling. The aim of the this study was to evaluate the bone formation potential of 400μg ALN delivered in β-TCP in the treatment of periodontal intra-osseous defects. Thirty patients with periodontal defects were randomly assigned to 400μg ALN + β-TCP + Saline (test) group and β-TCP + Saline (active-control) group. Clinical parameters like Clinical Attachment Level (CAL) gain, Probing Depth (PD) reduction, post-operative Gingival Recession (GR) were assessed from the baseline, 3 months and 6 months recordings. Radiographic parameters like Linear Bone Growth (LBG), Percentage Bone Fill (%BF), and change in alveolar crest height (ACH) were assessed from baseline and 6 months radiographs. Mean measurements in the ALN test group for CAL gain (3.4 ± 0.74 mm), PD reduction (4.33 ± 0.82 mm), LBG (2.88 ± 0.88 mm), and %BF (51.98 ± 15.84%) were significantly greater with a p-value TCP bone graft material was effective in improving soft tissue parameters, inhibiting alveolar crestal resorption and enhancing bone formation, compared to β-TCP alone.

  6. Continuous Curvilinear Capsulorhexis Training and Non-Rhexis Related Vitreous Loss: The Specificity of Virtual Reality Simulator Surgical Training (An American Ophthalmological Society Thesis). (United States)

    McCannel, Colin A


    To assess the specificity of simulation-based virtual reality ophthalmic cataract surgery training on the Eyesi ophthalmic virtual reality surgical simulator, and test the hypothesis that microsurgical motor learning is highly specific. Retrospective educational interventional case series. The rates of vitreous loss and retained lens material, and vitreous loss and retained lens material associated with an errant continuous curvilinear capsulorhexis (CCC) were assessed among 1037 consecutive cataract surgeries performed during four consecutive academic years at a teaching hospital. The data were grouped by Eyesi use and capsulorhexis intensive training curriculum (CITC) completion. The main intervention was the completion of the CITC on the Eyesi. In the Eyesi simulator experience-based stratification, the vitreous loss rate was similar in each group (chi square p=0.95) and was not preceded by an errant CCC in 86.2% for "CITC done at least once", 57.1% for "CITC not done, but some Eyesi use", and 48.9% for "none" training groups (p=4×10-5). Retained lens material overall and occurring among the errant CCC cases was similar among training groups (p=0.82 and p=0.71, respectively). Eyesi capsulorhexis training was not associated with lower vitreous loss rates overall. However, non-errant CCC associated vitreous loss was higher among those who underwent Eyesi capsulorhexis training. Training focused on the CCC portion of cataract surgery may not reduce vitreous loss unassociated with an errant CCC. It is likely that surgical training is highly specific to the task being trained. Residents may need to be trained for all surgical steps with adequate intensity to minimize overall complication rates.

  7. The efficacy of the use of IR laser phototherapy associated to biphasic ceramic graft and guided bone regeneration on surgical fractures treated with wire osteosynthesis: a comparative laser fluorescence and Raman spectral study on rabbits. (United States)

    Pinheiro, Antônio Luiz Barbosa; Santos, Nicole Ribeiro Silva; Oliveira, Priscila Chagas; Aciole, Gilberth Tadeu Santos; Ramos, Thais Andrade; Gonzalez, Tayná Assunção; da Silva, Laís Nogueira; Barbosa, Artur Felipe Santos; Silveira, Landulfo


    The aim of the present study was to assess, by Raman spectroscopy and laser fluorescence, the repair of surgical fractures fixed with wire osteosynthesis treated or not with infrared laser (λ780 nm, 50 mW, 4 × 4 J/cm(2) =16 J/cm(2), ϕ=0.5 cm(2), CW) associated or not to the use of hydroxyapatite and guided bone regeneration. Surgical tibial fractures were created under general anesthesia on 15 rabbits that were divided into five groups, maintained on individual cages, at day/night cycle, fed with solid laboratory pelted diet, and had water ad libitum. The fractures in groups II, III, IV, and V were fixed with wires. Animals in groups III and V were grafted with hydroxyapatite (HA) and guided bone regeneration (GBR) technique used. Animals in groups IV and V were irradiated at every other day during 2 weeks (4 × 4 J/cm(2), 16 J/cm(2) =112 J/cm(2)). Observation time was that of 30 days. After animal death, specimens were taken and kept in liquid nitrogen and used for Raman spectroscopy. The Raman results showed basal readings of 1,234.38 ± 220. Groups WO+B+L showed higher readings (1,680.22 ± 822) and group WO+B the lowest (501.425 ± 328). Fluorescence data showed basal readings of 5.83333 ± 0.7. Groups WO showed higher readings (6.91667 ± 0.9) and group WO+B+L the lowest (1.66667 ± 0.5). There were significant differences between groups on both cases (pbone healing on fractured bones as a result of the increasing deposition of CHA measured by Raman spectroscopy and decrease of the organic components as shown by the fluorescence readings.

  8. Medium-Term Function of a 3D Printed TCP/HA Structure as a New Osteoconductive Scaffold for Vertical Bone Augmentation: A Simulation by BMP-2 Activation

    Directory of Open Access Journals (Sweden)

    Mira Moussa


    Full Text Available Introduction: A 3D-printed construct made of orthogonally layered strands of tricalcium phosphate (TCP and hydroxyapatite has recently become available. The material provides excellent osteoconductivity. We simulated a medium-term experiment in a sheep calvarial model by priming the blocks with BMP-2. Vertical bone growth/maturation and material resorption were evaluated. Materials and methods: Titanium hemispherical caps were filled with either bare- or BMP-2 primed constructs and placed onto the calvaria of adult sheep (n = 8. Histomorphometry was performed after 8 and 16 weeks. Results: After 8 weeks, relative to bare constructs, BMP-2 stimulation led to a two-fold increase in bone volume (Bare: 22% ± 2.1%; BMP-2 primed: 50% ± 3% and a 3-fold decrease in substitute volume (Bare: 47% ± 5%; BMP-2 primed: 18% ± 2%. These rates were still observed at 16 weeks. The new bone grew and matured to a haversian-like structure while the substitute material resorbed via cell- and chemical-mediation. Conclusion: By priming the 3D construct with BMP-2, bone metabolism was physiologically accelerated, that is, enhancing vertical bone growth and maturation as well as material bioresorption. The scaffolding function of the block was maintained, leaving time for the bone to grow and mature to a haversian-like structure. In parallel, the material resorbed via cell-mediated and chemical processes. These promising results must be confirmed in clinical tests.

  9. Bone tumor (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor; Bone tumor - benign ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  10. The Maxillary Sinus Membrane Elevation Procedure: Augmentation of Bone around Dental Implants without Grafts—A Review of a Surgical Technique

    Directory of Open Access Journals (Sweden)

    Christopher Riben


    Full Text Available Background. Long-term edentulism may in many cases result in resorption of the alveolar process. The sinus lift procedure aims to create increased bone volume in the maxillary sinus in order to enable installation of dental implants in the region. The method is over 30 years old, and initially autogenous bone grafts were used and later also different bone substitutes. Since 1997, a limited number of studies have explored the possibility of a graftless procedure where the void under the sinus membrane is filled with a blood clot that enables bone formation. Aim. To describe the evolution of the sinus-lift technique and to review the literature related to the technique with a focus on long-term studies related to the graft-less technique. Methods. The electronic database PubMed was searched, and a systematic review was conducted regarding relevant articles. Results. A relatively few long-term studies using the described technique were found. However, the technique was described as reliable considering the outcome of the existing studies. Conclusion. All investigated studies show high implant survival rates for the graftless technique. The technique is considered to be cost-effective, less time-consuming, and related to lower morbidity since no bone harvesting is needed.

  11. A study of murine bone marrow cells cultured in bioreactors which create an environment which simulated microgravity (United States)

    Lawless, Brother Desales


    Previous research indicated that mouse bone marrow cells could be grown in conditions of simulated microgravity. This environment was created in rotating bioreactor vessels. On three attempts mouse cells were grown successfully in the vessels. The cells reached a stage where the concentrations were doubling daily. Phenotypic analysis using a panel of monoclonal antibodies indicated that the cell were hematopoietic pluripotent stem cells. One unsuccessful attempt was made to reestablish the immune system in immunocompromised mice using these cells. Since last summer, several unsuccessful attempts were made to duplicate these results. It was determined by electron microscopy that the cells successfully grown in 1989 contained virus particles. It was suggested that these virally parasitized cells had been immortalized. The work of this summer is a continuation of efforts to grow mouse bone marrow in these vessels. A number of variations of the protocol were introduced. Certified pathogen free mice were used in the repeat experiments. In some attempts the medium of last summer was used; in others Dexture Culture Medium containing Iscove's Medium supplemented with 20 percent horse serum and 10-6 M hydrocortisone. Efforts this summer were directed solely to repeating the work of last summer. Plans were made for investigations if stem cells were isolated. Immortalization of the undifferentiated stem cell would be attempted by transfection with an oncogenic vector. Selective differentiation would be induced in the stem cell line by growing it with known growth factors and immune response modulators. Interest is in identifying any surface antigens unique to stem cells that would help in their characterization. Another goal was to search for markers on stem cells that would distinguish them from stem cells committed to a particular lineage. If the undifferentiated hematopoietic stem cell was obtained, the pathways that would terminally convert it to myeloid, lyphoid

  12. Effect of porous orthopaedic implant material and structure on load sharing with simulated bone ingrowth: A finite element analysis comparing titanium and PEEK. (United States)

    Carpenter, R Dana; Klosterhoff, Brett S; Torstrick, F Brennan; Foley, Kevin T; Burkus, J Kenneth; Lee, Christopher S D; Gall, Ken; Guldberg, Robert E; Safranski, David L


    Osseointegration of load-bearing orthopaedic implants, including interbody fusion devices, is critical to long-term biomechanical functionality. Mechanical loads are a key regulator of bone tissue remodeling and maintenance, and stress-shielding due to metal orthopaedic implants being much stiffer than bone has been implicated in clinical observations of long-term bone loss in tissue adjacent to implants. Porous features that accommodate bone ingrowth have improved implant fixation in the short term, but long-term retrieval studies have sometimes demonstrated limited, superficial ingrowth into the pore layer of metal implants and aseptic loosening remains a problem for a subset of patients. Polyether-ether-ketone (PEEK) is a widely used orthopaedic material with an elastic modulus more similar to bone than metals, and a manufacturing process to form porous PEEK was recently developed to allow bone ingrowth while preserving strength for load-bearing applications. To investigate the biomechanical implications of porous PEEK compared to porous metals, we analyzed finite element (FE) models of the pore structure-bone interface using two clinically available implants with high (> 60%) porosity, one being constructed from PEEK and the other from electron beam 3D-printed titanium (Ti). The objective of this study was to investigate how porous PEEK and porous Ti mechanical properties affect load sharing with bone within the porous architectures over time. Porous PEEK substantially increased the load share transferred to ingrown bone compared to porous Ti under compression (i.e. at 4 weeks: PEEK = 66%; Ti = 13%), tension (PEEK = 71%; Ti = 12%), and shear (PEEK = 68%; Ti = 9%) at all time points of simulated bone ingrowth. Applying PEEK mechanical properties to the Ti implant geometry and vice versa demonstrated that the observed increases in load sharing with PEEK were primarily due to differences in intrinsic elastic modulus and not pore architecture (i.e. 4 weeks

  13. Modification of planned postoperative occlusion in orthognathic surgery, based on computer-aided design/computer-aided manufacturing-engineered preoperative surgical simulation. (United States)

    Kang, Sang-Hoon; Kim, Moon-Key; You, Tae-Kwon; Lee, Ji-Yeon


    In orthognathic surgery, it is important to have a planned postoperative occlusion. A 3-dimensional preoperative simulation, based on 3-dimensional optically scanned occlusion data, can predict how the planned postoperative occlusion will affect the maxilla-mandibular relationship that results from orthognathic surgery. In this study we modified the planned postoperative occlusion, based on computer-aided design/computer-aided manufacturing-engineered preoperative surgical simulations. This modification made it possible to resolve the facial asymmetry of the patient successfully with a simple bilateral intraoral vertical ramus osteotomy and no additional maxillary or mandibular surgery. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Implementation of a novel portfolio of structured, curriculum-aligned, simulation-based, cardiothoracic surgery training courses: Evolving the delivery of surgical education. (United States)

    Moorjani, Narain; Lewis, Michael; Shah, Rajesh; Barnard, Sion; Graham, Tim; Rathinam, Sridhar


    The provision of high-quality cardiothoracic surgical training faces many challenges. This has generated an increased interest in simulation-based learning, which can provide a less stressful environment for deliberate practice. We developed a comprehensive, structured program of knowledge and simulation-based learning aligned to the official cardiothoracic surgery curriculum. A portfolio of 10 curriculum-aligned training courses was designed for cardiothoracic surgical trainees during their 6-year training program. The courses were delivered through a multitude of education methods, including live porcine operating simulation models, and were evaluated through a series of quantitative (5-point Likert-scale) and qualitative assessments. The trainees (n = 15-21 per course) also completed pre- and postsession self-confidence and competency levels for each training episode of knowledge and skill, respectively. In addition, board examination pass rates were assessed in the 3-year periods before and after implementation of the courses. Quantitative analysis of the trainees' feedback demonstrated an extremely positive view of the portfolio of the simulation-based training courses with excellent satisfaction scores (out of 5) for teaching sessions (4.44 ± 0.07), faculty (4.64 ± 0.07), content and materials (4.63 ± 0.07), and facilities (4.73 ± 0.05). The courses have shown a significant improvement in the post-self-confidence (7.98 ± 0.13 vs 5.62 ± 0.20, P training in cardiothoracic surgery. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

  15. Bone autografting of the calvaria and craniofacial skeleton: historical background, surgical results in a series of 15 patients, and review of the literature. (United States)

    Artico, Marco; Ferrante, Luigi; Pastore, Francesco Saverio; Ramundo, Epimenio Orlando; Cantarelli, Davide; Scopelliti, Domenico; Iannetti, Giorgio


    Although the use of autologous bone for reconstruction of the cranial and facial skeleton underwent a partial reappraisal following the introduction of a vast range of alloplastic materials for this purpose, it has demonstrated definite advantages over the last century and, particularly, during the last decade. Fifteen patients underwent cranial and/or cranio-facial reconstruction using autologous bone grafting in the Department of Neurologic Sciences-Neurosurgery and the Division of Maxillo-Facial Surgery of the Rome "La Sapienza" University between 1987 and 1995. This group of patients consisted of 8 females and 7 males whose average age was 29.5 years (range 7.5 to 59 years, mean age 30). In all these patients cranioplasty and/or cranio-facial reconstruction had been performed to repair bone defects secondary to benign tumors or tumor-like lesions (12 cases), trauma (2 cases), or, in the remaining case, to wound infection after craniotomy for a neurosurgical operation. The results obtained in a series of 15 patients treated using this method are described with reference to the abundant data published on this topic. The mechanical, immunologic, and technical-grafting properties of autologous bone, together with its superior esthetic and psychological effects, probably make it the best material for cranioplasty.

  16. Simulating the Lunar Environment: Partial Weightbearing and High-LET Radiation-Induce Bone Loss and Increase Sclerostin-Positive Osteocytes. (United States)

    Macias, B R; Lima, F; Swift, J M; Shirazi-Fard, Y; Greene, E S; Allen, M R; Fluckey, J; Hogan, H A; Braby, L; Wang, Suojin; Bloomfield, S A


    Exploration missions to the Moon or Mars will expose astronauts to galactic cosmic radiation and low gravitational fields. Exposure to reduced weightbearing and radiation independently result in bone loss. However, no data exist regarding the skeletal consequences of combining low-dose, high-linear energy transfer (LET) radiation and partial weightbearing. We hypothesized that simulated galactic cosmic radiation would exacerbate bone loss in animals held at one-sixth body weight (G/6) without radiation exposure. Female BALB/cByJ four-month-old mice were randomly assigned to one of the following treatment groups: 1 gravity (1G) control; 1G with radiation; G/6 control; and G/6 with radiation. Mice were exposed to either silicon-28 or X-ray radiation. (28)Si radiation (300 MeV/nucleon) was administered at acute doses of 0 (sham), 0.17 and 0.5 Gy, or in three fractionated doses of 0.17 Gy each over seven days. X radiation (250 kV) was administered at acute doses of 0 (sham), 0.17, 0.5 and 1 Gy, or in three fractionated doses of 0.33 Gy each over 14 days. Bones were harvested 21 days after the first exposure. Acute 1 Gy X-ray irradiation during G/6, and acute or fractionated 0.5 Gy (28)Si irradiation during 1G resulted in significantly lower cancellous mass [percentage bone volume/total volume (%BV/TV), by microcomputed tomography]. In addition, G/6 significantly reduced %BV/TV compared to 1G controls. When acute X-ray irradiation was combined with G/6, distal femur %BV/TV was significantly lower compared to G/6 control. Fractionated X-ray irradiation during G/6 protected against radiation-induced losses in %BV/TV and trabecular number, while fractionated (28)Si irradiation during 1G exacerbated the effects compared to single-dose exposure. Impaired bone formation capacity, measured by percentage mineralizing surface, can partially explain the lower cortical bone thickness. Moreover, both partial weightbearing and (28)Si-ion exposure contribute to a higher proportion of

  17. Primary implant stability in a bone model simulating clinical situations for the posterior maxilla: an in vitro study (United States)


    Purpose The aim of this study was to determine the influence of anatomical conditions on primary stability in the models simulating posterior maxilla. Methods Polyurethane blocks were designed to simulate monocortical (M) and bicortical (B) conditions. Each condition had four subgroups measuring 3 mm (M3, B3), 5 mm (M5, B5), 8 mm (M8, B8), and 12 mm (M12, B12) in residual bone height (RBH). After implant placement, the implant stability quotient (ISQ), Periotest value (PTV), insertion torque (IT), and reverse torque (RT) were measured. Two-factor ANOVA (two cortical conditions×four RBHs) and additional analyses for simple main effects were performed. Results A significant interaction between cortical condition and RBH was demonstrated for all methods measuring stability with two-factor ANOVA. In the analyses for simple main effects, ISQ and PTV were statistically higher in the bicortical groups than the corresponding monocortical groups, respectively. In the monocortical group, ISQ and PTV showed a statistically significant rise with increasing RBH. Measurements of IT and RT showed a similar tendency, measuring highest in the M3 group, followed by the M8, the M5, and the M12 groups. In the bicortical group, all variables showed a similar tendency, with different degrees of rise and decline. The B8 group showed the highest values, followed by the B12, the B5, and the B3 groups. The highest coefficient was demonstrated between ISQ and PTV. Conclusions Primary stability was enhanced by the presence of bicortex and increased RBH, which may be better demonstrated by ISQ and PTV than by IT and RT. PMID:27588215

  18. Monte Carlo simulation of neutron irradiation facility developed for accelerator based in vivo neutron activation measurements in human hand bones

    International Nuclear Information System (INIS)

    Aslam; Prestwich, W.V.; McNeill, F.E.; Waker, A.J.


    The neutron irradiation facility developed at the McMaster University 3 MV Van de Graaff accelerator was employed to assess in vivo elemental content of aluminum and manganese in human hands. These measurements were carried out to monitor the long-term exposure of these potentially toxic trace elements through hand bone levels. The dose equivalent delivered to a patient during irradiation procedure is the limiting factor for IVNAA measurements. This article describes a method to estimate the average radiation dose equivalent delivered to the patient's hand during irradiation. The computational method described in this work augments the dose measurements carried out earlier [Arnold et al., 2002. Med. Phys. 29(11), 2718-2724]. This method employs the Monte Carlo simulation of hand irradiation facility using MCNP4B. Based on the estimated dose equivalents received by the patient hand, the proposed irradiation procedure for the IVNAA measurement of manganese in human hands [Arnold et al., 2002. Med. Phys. 29(11), 2718-2724] with normal (1 ppm) and elevated manganese content can be carried out with a reasonably low dose of 31 mSv to the hand. Sixty-three percent of the total dose equivalent is delivered by non-useful fast group (>10 keV); the filtration of this neutron group from the beam will further decrease the dose equivalent to the patient's hand

  19. Synergistic role of hydroxyapatite nanoparticles and pulsed electromagnetic field therapy to prevent bone loss in rats following exposure to simulated microgravity

    Directory of Open Access Journals (Sweden)

    D Prakash


    Full Text Available D Prakash, J BehariSchool of Environmental Sciences, Jawaharlal Nehru University, New Delhi, IndiaAbstract: The purpose of the present study was to use capacitive coupling of pulsed electromagnetic field (CC-PEMF and hydroxyapatite nanoparticles (HAp as a countermeasure to prevent osteoporosis induced by simulated microgravity. We used the hind-limb suspension (HLS rat model to simulate microgravity-induced bone losses for 45 days. In order to compare the resulting changes, mineralogical (bone mineral density [BMD], calcium [Ca], and phosphorus [P], biochemical (osteocalcin, alkaline phosphatase [ALP], and type I collagen, and histological (scanning electron microscopy parameters were adopted. As a countermeasure to the above, the effect of PEMF and HAp application were examined. Three-month-old female Wistar rats were randomly divided into control (n = 8, HLS (n = 8, HLS with PEMF (n = 8, HLS with HAp nanoparticles (n = 8, and HLS with HAp and PEMF (n = 8. We observed: 1 significant decrease (p < 0.01 in BMD, Ca, P, type I collagen, and ALP activity in femur and tibia in hind-limb bone and serum osteocalcin in HLS rats as compared with the ground control. 2 Nonsignificant increase in BMD (p < 0.1, Ca (p < 0.1, P (p < 0.5, type I collagen (p < 0.1, and ALP activity (p < 0.5 in femur and tibia in hind-limb bone and serum osteocalcin (p < 0.5 in HLS + PEMF rats compared with HLS rats. 3 Significant increase in BMD (p < 0.02, Ca (p < 0.05, P (p < 0.05, type I collagen (p < 0.02, and ALP activity (p > 0.02 in femur and tibia in hind-limb bone with a nonsignificant increase in serum osteocalcin (p > 0.1 in HLS + HAp rats compared to HLS rats. 4 Significant increase in BMD (p > 0.01. Ca (p > 0.01. P (p > 0.01. type I collagen (p > 0.01. and ALP activity (p > 0.01 in femur and tibia in hind-limb bone and serum osteocalcin (p > 0.02 were also observed. Results suggest that a combination of low level PEMF and Hap nanoparticles has potential to control

  20. An Examination of Surgical Skill Performance under Combat Conditions Using a Mannequin-Based Simulator in a Virtual Environment

    National Research Council Canada - National Science Library

    Scerbo, Mark W; Weireter, Jr., Leonard J; Bliss, James P; Schmidt, Elizabeth A; Hanner, Hope


    .... The participants then performed the procedure in a fully immersive CAVE virtual environment running a combat simulation including gunfire, explosions, and a virtual sniper under both daylight and nighttime conditions...

  1. Radioisotopic evaluation of bone repair after experimental surgical trauma Avaliação radiofarmacológica do reparo ósseo após trauma cirúrgico padronizado

    Directory of Open Access Journals (Sweden)

    Ana Cristina Breithaupt-Faloppa


    Full Text Available BACKGROUND: Scientific approach of the bone reaction after surgical procedures provides valuable information on methods and techniques. The purpose of this study was to follow this process using a radioisotope marker of bone remodelling. MATERIAL AND METHODS: Two bone cavities were created (one for every tibia in adult Wistar male rats using a 0.5 mm spherical burr; left tibial cavities were filled with bovine freeze-dried bone; the right ones were left unfilled for control. Scintigrams were done with sodium methylene diphosphonate (MDP labelled with radioactive pertechnetate (99mTcO4- to evaluate the inflammatory response and the local osteoblastic activity. The evolution of bone repair was additionally evaluated by light microscopy. RESULTS: Our results have shown that the highest bone activity was recorded between the 7th and the 14th day after surgery. The morphological analysis confirmed the results obtained with radioisotope analysis and did not reveal significant differences regarding the evolution of bone repair between the filled and the unfilled defects. CONCLUSION: We confirmed that 99mTc -MDP is a valuable tool to study bone repair, as it was able to show subtle alterations of bone activity even in lesions as small as those created herein (0.5 mm wide, 0.5 mm deep.Este trabalho objetivou estudar a evolução temporal do processo de reparo ósseo em tíbia de rato, após trauma cirúrgico padronizado. A incorporação do radiofármaco 99mTc-MDP na região afetada foi tomada como medida indireta da intensidade de reação tecidual; foi feito também acompanhamento histológico do processo de reparo. Foram realizadas cirurgias nas duas tíbias de 72 animais divididos em 2 grupos, sendo sacrificados em diferentes dias pós-operatórios (1, 3, 7, 14, 21 e 28 dias p.o.. As cavidades criadas nas tíbias esquerdas foram preenchidas com osso liofilizado bovino, e as direitas serviram como controle (não preenchidas. Grupos paralelos de

  2. 3D Rapid Prototyping for Otolaryngology—Head and Neck Surgery: Applications in Image-Guidance, Surgical Simulation and Patient-Specific Modeling (United States)

    Chan, Harley H. L.; Siewerdsen, Jeffrey H.; Vescan, Allan; Daly, Michael J.; Prisman, Eitan; Irish, Jonathan C.


    The aim of this study was to demonstrate the role of advanced fabrication technology across a broad spectrum of head and neck surgical procedures, including applications in endoscopic sinus surgery, skull base surgery, and maxillofacial reconstruction. The initial case studies demonstrated three applications of rapid prototyping technology are in head and neck surgery: i) a mono-material paranasal sinus phantom for endoscopy training ii) a multi-material skull base simulator and iii) 3D patient-specific mandible templates. Digital processing of these phantoms is based on real patient or cadaveric 3D images such as CT or MRI data. Three endoscopic sinus surgeons examined the realism of the endoscopist training phantom. One experienced endoscopic skull base surgeon conducted advanced sinus procedures on the high-fidelity multi-material skull base simulator. Ten patients participated in a prospective clinical study examining patient-specific modeling for mandibular reconstructive surgery. Qualitative feedback to assess the realism of the endoscopy training phantom and high-fidelity multi-material phantom was acquired. Conformance comparisons using assessments from the blinded reconstructive surgeons measured the geometric performance between intra-operative and pre-operative reconstruction mandible plates. Both the endoscopy training phantom and the high-fidelity multi-material phantom received positive feedback on the realistic structure of the phantom models. Results suggested further improvement on the soft tissue structure of the phantom models is necessary. In the patient-specific mandible template study, the pre-operative plates were judged by two blinded surgeons as providing optimal conformance in 7 out of 10 cases. No statistical differences were found in plate fabrication time and conformance, with pre-operative plating providing the advantage of reducing time spent in the operation room. The applicability of common model design and fabrication techniques

  3. 3D Rapid Prototyping for Otolaryngology-Head and Neck Surgery: Applications in Image-Guidance, Surgical Simulation and Patient-Specific Modeling.

    Directory of Open Access Journals (Sweden)

    Harley H L Chan

    Full Text Available The aim of this study was to demonstrate the role of advanced fabrication technology across a broad spectrum of head and neck surgical procedures, including applications in endoscopic sinus surgery, skull base surgery, and maxillofacial reconstruction. The initial case studies demonstrated three applications of rapid prototyping technology are in head and neck surgery: i a mono-material paranasal sinus phantom for endoscopy training ii a multi-material skull base simulator and iii 3D patient-specific mandible templates. Digital processing of these phantoms is based on real patient or cadaveric 3D images such as CT or MRI data. Three endoscopic sinus surgeons examined the realism of the endoscopist training phantom. One experienced endoscopic skull base surgeon conducted advanced sinus procedures on the high-fidelity multi-material skull base simulator. Ten patients participated in a prospective clinical study examining patient-specific modeling for mandibular reconstructive surgery. Qualitative feedback to assess the realism of the endoscopy training phantom and high-fidelity multi-material phantom was acquired. Conformance comparisons using assessments from the blinded reconstructive surgeons measured the geometric performance between intra-operative and pre-operative reconstruction mandible plates. Both the endoscopy training phantom and the high-fidelity multi-material phantom received positive feedback on the realistic structure of the phantom models. Results suggested further improvement on the soft tissue structure of the phantom models is necessary. In the patient-specific mandible template study, the pre-operative plates were judged by two blinded surgeons as providing optimal conformance in 7 out of 10 cases. No statistical differences were found in plate fabrication time and conformance, with pre-operative plating providing the advantage of reducing time spent in the operation room. The applicability of common model design and

  4. Difference in the Surgical Outcome of Unilateral Cleft Lip and Palate Patients with and without Pre-Alveolar Bone Graft Orthodontic Treatment (United States)

    Chang, Chun-Shin; Wallace, Christopher Glenn; Hsiao, Yen-Chang; Chiu, Yu-Ting; Pai, Betty Chien-Jung; Chen, I.-Ju; Liao, Yu-Fang; Liou, Eric Jen-Wein; Chen, Philip Kuo-Ting; Chen, Jyh-Ping; Noordhoff, M. Samuel


    Presurgical orthodontic treatment before secondary alveolar bone grafting (SABG) is widely performed for cleft lip/palate patients. However, no randomized controlled trial has been published comparing SABG outcomes in patients with, and without, presurgical orthodontic treatment. This randomized, prospective, single-blinded trial was conducted between January 2012 and April 2015 to compare ABG volumes 6 months postoperatively between patients with and without presurgical orthodontic treatment. Twenty-four patients were enrolled and randomized and 22 patients completed follow-up. Patients who had presurgical orthodontics before SABG had significantly improved inclination (p < 0.001) and rotation (p < 0.001) of the central incisor adjacent to the defect, significantly improved ABG fill volume (0.81 ± 0.26 cm3 at 6 months compared to 0.59 ± 0.22 cm3 p < 0.05) and less residual alveolar bone defect (0.31 ± 0.08 cm3 at 6 months compared to s 0.55 ± 0.14 cm3 p < 0.001) compared to patients who did not have presurgical orthodontic treatment. In conclusion, orthodontic treatment combined with SABG results in superior bone volume when compared with conventional SABG alone.

  5. Bone regeneration in dentistry (United States)

    Tonelli, Paolo; Duvina, Marco; Barbato, Luigi; Biondi, Eleonora; Nuti, Niccolò; Brancato, Leila; Rose, Giovanna Delle


    Summary The edentulism of the jaws and the periodontal disease represent conditions that frequently leads to disruption of the alveolar bone. The loss of the tooth and of its bone of support lead to the creation of crestal defects or situation of maxillary atrophy. The restoration of a functional condition involves the use of endosseous implants who require adequate bone volume, to deal with the masticatory load. In such situations the bone need to be regenerated, taking advantage of the biological principles of osteogenesis, osteoinduction and osteoconduction. Several techniques combine these principles with different results, due to the condition of the bone base on which we operate changes, the surgical technique that we use, and finally for the bone metabolic conditions of the patient who can be in a state of systemic osteopenia or osteoporosis; these can also affect the result of jaw bone reconstruction. PMID:22461825

  6. Use of three-dimensional, CAD/CAM-assisted, virtual surgical simulation and planning in the pediatric craniofacial population. (United States)

    Gray, Rachel; Gougoutas, Alexander; Nguyen, Vinh; Taylor, Jesse; Bastidas, Nicholas


    Virtual Surgical Planning (VSP) and computer-aided design/computer-aided manufacturing (CAD/CAM) have recently helped improve efficiency and accuracy in many different craniofacial surgeries. Research has mainly focused on the use in the adult population with the exception of the use for mandibular distractions and cranial vault remodeling in the pediatric population. This study aims to elucidate the role of VSP and CAD/CAM in complex pediatric craniofacial cases by exploring its use in the correction of midface hypoplasia, orbital dystopia, mandibular reconstruction, and posterior cranial vault expansion. A retrospective analysis of thirteen patients who underwent 3d, CAD/CAM- assisted preoperative surgical planning between 2012 and 2016 was performed. All CAD/CAM assisted surgical planning was done in conjunction with a third party vendor (either 3D Systems or Materialise). Cutting and positioning guides as well as models were produced based on the virtual plan. Surgeries included free fibula mandible reconstruction (n = 4), lefort I osteotomy and distraction (n = 2), lefort II osteotomy with monobloc distraction (n = 1), expansion of the posterior vault for correction of chiari malformation (n = 3), and secondary orbital and midface reconstruction for facial trauma (n = 3). The patient's age, diagnosis, previous surgeries, length of operating time, complications, and post-surgery satisfaction were determined. In all cases we found presurgical planning was helpful to improve accuracy and significantly decrease intra-operative time. In cases where distraction was used, the planned and actual vectors were found to be accurate with excellent clinical outcomes. There were no complications except for one patient who experienced a wound infection post-operatively which did not alter the ultimate reconstruction. All patients experienced high satisfaction with their outcomes and excellent subjective aesthetic results were achieved. Preoperative planning using

  7. Augmentation of bone healing in delayed and atrophic nonunion of fractures of long bones by partially decalcified bone allograft (decal bone

    Directory of Open Access Journals (Sweden)

    Anuj Jain


    Conclusion: The partially decalcified bone allograft is an effective modality for augmentation of bone healing without complication associated with autograft like donor site morbidity, increased blood loss and increase in the surgical time.

  8. Effect of Age of Self-Reported, Non-Surgical Menopause on Time to First Fracture and Bone Mineral Density in the Women’s Health Initiative Observational Study (United States)

    Lehman, Amy; Thomas, Fridtjof; Johnson, Karen C.; Jackson, Rebecca; Wactawski-Wende, Jean; Ko, Marcia; Chen, Zhao; Curb, J David; Howard, Barbara V.


    Objective Menopause is a risk factor for fracture, thus menopause age may affect bone mass and fracture rates. We compared Bone Mineral Density (BMD) and fracture rates among healthy postmenopausal women with varying ages of self-reported non-surgical menopause. Methods Hazard ratios for fracture and differences in BMD among 21,711 postmenopausal women from the Women’s Health Initiative Observational cohort without prior hysterectomy, oophorectomy, or hormone therapy, who reported age of menopause of menopausal age groups. After multivariable adjustments for known risk factors for fracture, women undergoing menopause menopause ≥50 years (HR=1.21, 95% CI: 1.02, 1.44; p=0.03). In a subset with BMD measurements (n=1,351), whole body BMD was lower in women who reported menopause menopause menopause menopause age may be a risk factor contributing to decreased BMD and increased fracture risk in healthy postmenopausal women. Our data suggest that menopause age should be taken into consideration, along with other osteoporotic risk factors, when estimating fracture risk in postmenopausal women. PMID:25803670

  9. The effect of implementing cognitive load theory-based design principles in virtual reality simulation training of surgical skills: a randomized controlled trial. (United States)

    Andersen, Steven Arild Wuyts; Mikkelsen, Peter Trier; Konge, Lars; Cayé-Thomasen, Per; Sørensen, Mads Sølvsten


    Cognitive overload can inhibit learning, and cognitive load theory-based instructional design principles can be used to optimize learning situations. This study aims to investigate the effect of implementing cognitive load theory-based design principles in virtual reality simulation training of mastoidectomy. Eighteen novice medical students received 1 h of self-directed virtual reality simulation training of the mastoidectomy procedure randomized for standard instructions (control) or cognitive load theory-based instructions with a worked example followed by a problem completion exercise (intervention). Participants then completed two post-training virtual procedures for assessment and comparison. Cognitive load during the post-training procedures was estimated by reaction time testing on an integrated secondary task. Final-product analysis by two blinded expert raters was used to assess the virtual mastoidectomy performances. Participants in the intervention group had a significantly increased cognitive load during the post-training procedures compared with the control group (52 vs. 41 %, p  = 0.02). This was also reflected in the final-product performance: the intervention group had a significantly lower final-product score than the control group (13.0 vs. 15.4, p  virtual reality surgical simulation training of novices.

  10. Anatomical education and surgical simulation based on the Chinese Visible Human: a three-dimensional virtual model of the larynx region. (United States)

    Liu, Kaijun; Fang, Binji; Wu, Yi; Li, Ying; Jin, Jun; Tan, Liwen; Zhang, Shaoxiang


    Anatomical knowledge of the larynx region is critical for understanding laryngeal disease and performing required interventions. Virtual reality is a useful method for surgical education and simulation. Here, we assembled segmented cross-section slices of the larynx region from the Chinese Visible Human dataset. The laryngeal structures were precisely segmented manually as 2D images, then reconstructed and displayed as 3D images in the virtual reality Dextrobeam system. Using visualization and interaction with the virtual reality modeling language model, a digital laryngeal anatomy instruction was constructed using HTML and JavaScript languages. The volume larynx models can thus display an arbitrary section of the model and provide a virtual dissection function. This networked teaching system of the digital laryngeal anatomy can be read remotely, displayed locally, and manipulated interactively.

  11. A crisis of faith? A review of simulation in teaching team-based, crisis management skills to surgical trainees. (United States)

    Doumouras, Aristithes G; Keshet, Itay; Nathens, Avery B; Ahmed, Najma; Hicks, Christopher M


    Team-based training using crisis resource management (CRM) has gained popularity as a strategy to minimize the impact of medical error during critical events. The purpose of this review was to appraise and summarize the design, implementation, and efficacy of peer-reviewed, simulation-based CRM training programs for postgraduate trainees (residents). Two independent reviewers conducted a structured literature review, querying multiple medical and allied health databases from 1950 to May 2010 (MEDLINE, EMBASE, CINAHL, EBM, and PsycINFO). We included articles that (1) were written in English, (2) were published in peer-reviewed journals, (3) included residents, (4) contained a simulation component, and (5) included a team-based component. Peer-reviewed articles describing the implementation of CRM instruction were critically appraised using the Kirkpatrick framework for evaluating training programs. Fifteen studies involving a total of 404 residents met inclusion criteria; most studies reported high resident satisfaction for CRM training. In several CRM domains, residents demonstrated significant improvements after training, which did not decay over time. With regard to design, oral feedback may be equivalent to video feedback and single-day interventions may be as efficacious as multiple-day interventions for residents. No studies demonstrated a link between simulation-based CRM training and performance during real-life critical events. The findings support the utility of CRM programs for residents. A high degree of satisfaction and perceived value reflect robust resident engagement. The iteration of themes from our review provides the basis for the development of best practices in curricula design. A dearth of well-designed, randomized studies preclude the quantification of impact of simulation-based training in the clinical environment. Copyright © 2012 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  12. Simulation-based end-of-life care training during surgical clerkship: assessment of skills and perceptions. (United States)

    Parikh, Priti P; Brown, Ronald; White, Mary; Markert, Ronald J; Eustace, Rosemary; Tchorz, Kathryn


    Assessment of interpersonal and psychosocial competencies during end-of-life care training is essential. This study reports the relationship between simulation-based end-of-life care Objective Structured Clinical Examination ratings and communication skills, trust, and self-assessed empathy along with the perceptions of students regarding their training experiences. Medical students underwent simulation-based end-of-life care OSCE training that involved standardized patients who evaluated students' communication skills and physician trust with the Kalamazoo Essential Elements Communication Checklist and the Wake Forest Physician Trust Scale. Students also completed the Jefferson Scale of Physician Empathy. Pearson correlation was used to examine the relationship between OSCE performance grades and communication, trust, and empathy scores. Student comments were analyzed using the constant comparative method of analysis to identify dominant themes. The 389 students (mean age 26.6 ± 2.8 y; 54.5% female) had OSCE grades that were positively correlated with physician trust scores (r = 0.325, P students perceived simulation-based end-of-life care training to be a valuable learning experience and appreciated its placement early in clinical training. We found that simulation-based OSCE training in palliative and end-of-life care can be effectively conducted during a surgery clerkship. Moreover, the standardized patient encounters combined with the formal assessment of communication skills, physician trust, and empathy provide feedback to students at an early phase of their professional life. The positive and appreciative comments of students regarding the opportunity to practice difficult patient conversations suggest that attention to these professional characteristics and skills is a valued element of clinical training and conceivably a step toward better patient outcomes and satisfaction. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Analysis and optimization of bone machining for robotic orthopedic surgeries. (United States)

    Pell, Derek J; Soshi, Masakazu


    Robot-assisted joint replacement surgery is becoming increasingly more common worldwide, therefore it is important to characterize and improve the bone-cutting mechanics of surgical tools. Linear coefficients relating cutting force and chip thickness were derived for a surgical spindle. The cutting coefficients were integrated into an analytical simulation which calculated cutting forces, torque, and power consumption. An optimization experiment was performed. High speed video was taken at various tool parameter settings. Varying machining parameters resulted in lower cutting forces. The surgical spindle stalled at the current spindle speed used in surgery, but did not for the new, optimized conditions. Multiple anomalies were identified in the videos that confirmed observations from the cutting force data. Improved surgical performance and accuracy were achieved using slower spindle speeds, decreased cutting depth, and increased feed rates, as well as improving motor torque to ensure a smooth cutting process. Copyright © 2018 John Wiley & Sons, Ltd.

  14. Chitosan nanofiber scaffold improves bone healing via stimulating trabecular bone production due to upregulation of the Runx2/osteocalcin/alkaline phosphatase signaling pathway (United States)

    Ho, Ming-Hua; Yao, Chih-Jung; Liao, Mei-Hsiu; Lin, Pei-I; Liu, Shing-Hwa; Chen, Ruei-Ming


    Osteoblasts play critical roles in bone formation. Our previous study showed that chitosan nanofibers can stimulate osteoblast proliferation and maturation. This translational study used an animal model of bone defects to evaluate the effects of chitosan nanofiber scaffolds on bone healing and the possible mechanisms. In this study, we produced uniform chitosan nanofibers with fiber diameters of approximately 200 nm. A bone defect was surgically created in the proximal femurs of male C57LB/6 mice, and then the left femur was implanted with chitosan nanofiber scaffolds for 21 days and compared with the right femur, which served as a control. Histological analyses revealed that implantation of chitosan nanofiber scaffolds did not lead to hepatotoxicity or nephrotoxicity. Instead, imaging analyses by X-ray transmission and microcomputed tomography showed that implantation of chitosan nanofiber scaffolds improved bone healing compared with the control group. In parallel, microcomputed tomography and bone histomorphometric assays further demonstrated augmentation of the production of new trabecular bone in the chitosan nanofiber-treated group. Furthermore, implantation of chitosan nanofiber scaffolds led to a significant increase in the trabecular bone thickness but a reduction in the trabecular parameter factor. As to the mechanisms, analysis by confocal microscopy showed that implantation of chitosan nanofiber scaffolds increased levels of Runt-related transcription factor 2 (Runx2), a key transcription factor that regulates osteogenesis, in the bone defect sites. Successively, amounts of alkaline phosphatase and osteocalcin, two typical biomarkers that can simulate bone maturation, were augmented following implantation of chitosan nanofiber scaffolds. Taken together, this translational study showed a beneficial effect of chitosan nanofiber scaffolds on bone healing through stimulating trabecular bone production due to upregulation of Runx2-mediated alkaline

  15. Effects of tibial baseplate shape on rotational alignment in total knee arthroplasty: three-dimensional surgical simulation using osteoarthritis knees. (United States)

    Ma, Yuan; Mizu-Uchi, Hideki; Okazaki, Ken; Ushio, Tetsuro; Murakami, Koji; Hamai, Satoshi; Akasaki, Yukio; Nakashima, Yasuharu


    Placement of tibial component is expected to fulfill both maximum surface coverage and recommended anterior-posterior (AP) alignment in total knee arthroplasty (TKA). The purpose of this study is to evaluate the effect of the tibial baseplate shape on AP axis. Virtual surgery of TKA was performed with three-dimensional bone models reconstructed from 77 osteoarthritis varus knees. Two differently designed tibial baseplates, symmetrically and anatomically, were set to the cut surface under posterior slopes of 0°, 3°, and 7°. The AP axes were defined by connecting the geometrical center of the cut surface with the medial edge (axis MED) and medial 1/3 (axis 1/3MED) of patella tendon attachment. We evaluated the overhang rates as well as the most fitting AP axis which passes through the geometric center. Overhang rates when aligned to axis MED were 12-25% for the symmetrical-type group and 13-22% for the anatomical-type group. Overhang rates when aligned to axis 1/3MED were 42-48% for the symmetrical-type group and 3-7% for the anatomical-type group. The most fitting AP axis of tibial baseplate was located 2.5° external to axis MED for the symmetrical-type group and around 3.3° internal to axis 1/3MED for the anatomical-type group. Symmetrically or anatomically designed tibial baseplates have their own favored AP axis and specific performance on coverage. When aligned to axis 1/3MED, anatomically designed tibial baseplates will effectively lower the mismatch rates compared to a symmetrically designed tibial baseplate. Orthopaedic surgeons are expected to place the tibial components to the cut surface during TKA with full understanding of the features between different baseplate designs, AP axes, and posterior slopes for an ideal tibial rotational position.

  16. Objective Surgical Skill Assessment: An Initial Experience by Means of a Sensory Glove Paving the Way to Open Surgery Simulation? (United States)

    Saggio, Giovanni; Lazzaro, Alessandra; Sbernini, Laura; Carrano, Francesco Maria; Passi, Davide; Corona, Arianna; Panetta, Valentina; Gaspari, Achille L; Di Lorenzo, Nicola


    Simulation and training in surgery are very promising tools for enhancing a surgeon's skill base. Accurate tracking of hand movements can be a strategy for objectively gauging a surgeon's dexterity, although "open" work is much more difficult to evaluate than are laparoscopic tasks. To the authors' knowledge, a system taking into account the movements of each finger joint has never been applied to open surgery simulation. This work intends to make up for this shortcoming and to perform a data analysis of the surgeon's entire gesture. The authors developed a sensory glove to measure flexion/extension of each finger joint and wrist movement. Totally 9 experts and 9 novices performed a basic suturing task and their manual performances were recorded within 2 days of measurements. Intraclass correlation coefficients were calculated to assess the ability of the executors to repeat and reproduce the proposed exercise. Wilcoxon signed-rank tests and Mann-Whitney U-tests were used to determine whether the 2 groups differ significantly in terms of execution time, repeatability, and reproducibility. Finally, a questionnaire was used to gather operators' subjective opinions. The experts needed a similar reduced execution time comparing the 2 recording sessions (p = 0.09), whereas novices spent more time during the first day (p = 0.01). Repeatability did not differ between the 2 days, either for experts (p = 0.26) or for novices (p = 0.86). The 2 groups performed differently in terms of time (p paving the way to a more complex project involving open surgery simulation. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  17. Clinical determination of target registration error of an image-guided otologic surgical system using patients with bone-anchored hearing aids (United States)

    Balachandran, Ramya; Labadie, Robert F.; Fitzpatrick, J. Michael


    Image guidance in otologic surgery has been thwarted by the need for a non-invasive fiducial system with target registration error (TRE) at the inner ear below 1.5mm. We previously presented a fiducial frame for this purpose that attaches to the upper dentition via patient-specific bite blocks and demonstrated a TRE of 0.73mm (+/-0.23mm) on cadaveric skulls. In that study, TRE measurement depended upon placement of bone-implanted, intracranial target fiducials-clearly impossible to repeat clinically. Using cadaveric specimens, we recently presented a validation method based on an auditory implant system (BAHA System® Cochlear Corp., Denver, CO). That system requires a skull-implanted titanium screw behind the ear upon which a bone-anchored hearing aid (BAHA) is mounted. In our validation, we replace the BAHA with a fiducial marker to permit measurement of TRE. That TRE is then used to estimate TRE at an internal point. While the method can be used to determine accuracy at any point within the head, we focus in this study on the inner ear, in particular the cochlea, and we apply the method to patients (N=5). Physical localizations were performed after varying elapsed times since bite-block fabrication, and TRE at the cochlea was estimated. We found TRE to be 0.97mm at the cochlea within one month and 2.5mm after seven months. Thus, while accuracy deteriorates considerably with delays of seven months or more, if this frame is used within one month of the fabrication of the bite-block, it achieves the goal and in fact exhibits submillimetric accuracy.

  18. Endoscopic instrument tracking for surgical simulation training in a controlled environment via a camera and a planar mirror. (United States)

    Dayak, Erdal; Çevik, Ulus


    Minimally Invasive Surgery (MIS) has many advantages over traditional procedures and thus training with MIS tools via computer simulations has received much attention. These tools are generally grouped into two major categories: Physical training-boxes, and Computer vision/Virtual Reality (VR) tools. In this study, a computer vision based simulator is proposed which uses a training box that is composed of a single camera and a planar mirror. Occlusions are appropriately handled by the use of the epipoint geometry. The average 3D positional error was 0.96mm (±0.44mm) at 1280×960 resolution, and 1.18mm (±0.52mm) at 320×240. So, the error is minimally affected as the resolution decreases. The proposed method has some advantages over relevant literature methods, such as an improved accuracy (approximately 60%) even at low resolutions with a low processing time (approximately 30%). Therefore, the proposed method appears as a promising and low cost (approximately 50%) alternative for computer vision based MIS training tools. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Bone Diseases (United States)

    ... avoid smoking and drinking too much alcohol. Bone diseases can make bones easy to break. Different kinds ... break Osteogenesis imperfecta makes your bones brittle Paget's disease of bone makes them weak Bones can also ...

  20. Stereoscopic (3D) versus monoscopic (2D) laparoscopy: comparative study of performance using advanced HD optical systems in a surgical simulator model. (United States)

    Schoenthaler, Martin; Schnell, Daniel; Wilhelm, Konrad; Schlager, Daniel; Adams, Fabian; Hein, Simon; Wetterauer, Ulrich; Miernik, Arkadiusz


    To compare task performances of novices and experts using advanced high-definition 3D versus 2D optical systems in a surgical simulator model. Fifty medical students (novices in laparoscopy) were randomly assigned to perform five standardized tasks adopted from the Fundamentals of Laparoscopic Surgery (FLS) curriculum in either a 2D or 3D laparoscopy simulator system. In addition, eight experts performed the same tasks. Task performances were evaluated using a validated scoring system of the SAGES/FLS program. Participants were asked to rate 16 items in a questionnaire. Overall task performance of novices was significantly better using stereoscopic visualization. Superiority of performances in 3D reached a level of significance for tasks peg transfer and precision cutting. No significant differences were noted in performances of experts when using either 2D or 3D. Overall performances of experts compared to novices were better in both 2D and 3D. Scorings in the questionnaires showed a tendency toward lower scores in the group of novices using 3D. Stereoscopic imaging significantly improves performance of laparoscopic phantom tasks of novices. The current study confirms earlier data based on a large number of participants and a standardized task and scoring system. Participants felt more confident and comfortable when using a 3D laparoscopic system. However, the question remains open whether these findings translate into faster and safer operations in a clinical setting.

  1. Bone graft substitutes and bone morphogenetic proteins for osteoporotic fractures: What is the evidence?

    NARCIS (Netherlands)

    E.M.M. van Lieshout (Esther); V. Alt (Volker)


    textabstractDespite improvements in implants and surgical techniques, osteoporotic fractures remain challenging to treat. Among other major risk factors, decreased expression of morphogenetic proteins has been identified for impaired fracture healing in osteoporosis. Bone grafts or bone graft

  2. Computer-assisted preoperative simulation for positioning of plate fixation in Lefort I osteotomy: A case report

    Directory of Open Access Journals (Sweden)

    Hideyuki Suenaga


    Full Text Available Computed tomography images are used for three-dimensional planning in orthognathic surgery. This facilitates the actual surgery by simulating the surgical scenario. We performed a computer-assisted virtual orthognathic surgical procedure using optically scanned three-dimensional (3D data and real computed tomography data on a personal computer. It helped maxillary bone movement and positioning and the titanium plate temporary fixation and positioning. This simulated the surgical procedure, which made the procedure easy, and we could perform precise actual surgery and could forecast the postsurgery outcome. This simulation method promises great potential in orthognathic surgery to help surgeons plan and perform operative procedures more precisely.

  3. A biomechanical comparison of headless tapered variable pitch compression and ao cortical bone screws for fixation of a simulated midbody transverse fracture of the proximal sesamoid bone in horses. (United States)

    Eddy, Alison L; Galuppo, Larry D; Stover, Susan M; Taylor, Kenneth T; Jensen, David G


    To compare mechanical properties and failure characteristics of 2 methods of fixation for repair of a transverse, midbody fracture of the proximal sesamoid bone (PSB): 4.5-mm AO cortical bone screw (AO) placed in lag fashion and 4/5-mm Acutrak (AT) self-compressing screw. An in vitro biomechanical evaluation of intact forelimb preparations and forelimb preparations with a simulated midbody PSB fracture stabilized by a bone screw. Sixteen paired and 8 unilateral cadaveric equine forelimbs. A midbody transverse osteotomy was created in the medial PSB of bilateral forelimbs of 8 equine cadavers. The osteotomized PSB in 1 forelimb from each cadaver was repaired with an AO screw. The osteotomized PSB in each contralateral limb was repaired with an AT screw. Eight unilateral intact control limbs were also studied. Mechanical properties were determined from axial compression, single cycle to failure, load-deformation curves. Failure characteristics were determined by evaluation of video images and radiographs. No statistically significant differences were found between repair groups. Both AO and AT groups had significantly lower mechanical properties than intact limbs except for stiffness. AO and AT constructs were mechanically comparable when used to stabilize a simulated midbody fracture of the medial PSB. Both constructs were mechanically inferior to intact limbs. Clinical Relevance- The AT screw should be considered for clinical use because of the potential for less soft tissue impingement and superior biocompatibility compared with the stainless-steel AO screw. However, postoperative external coaptation is necessary to augment initial fracture stability for either fixation method, and to maintain a standing metacarpophalangeal joint dorsiflexion angle between 150 degrees and 155 degrees.

  4. Recalcitrant aseptic atrophic non-union of the shaft of the humerus after failure of surgical treatment: management by excision of non-union, bone grafting and stabilization by LCP in different modes. (United States)

    Babhulkar, Sudhir; Babhulkar, Sushrut; Vasudev, Aditya


    Non-union of the humeral shaft is infrequently noticed after surgical fixation. Sixty eight patients whose osteosynthesis of humeral shaft had failed leading to non-union were identified over a duration of 10 years from (January 2006 to December 2015). Clinical and radiographical follow-up was available for 64 patients (4 patients were lost for follow-up), with a mean age of 58 years (range 25-78 years). All patients had aseptic atrophic non-union of either: proximal shaft (n=12), mid shaft (n=38), and lower shaft (n=14). All these patients had failure of primary fixation, with a minimum duration from 36 to 110 weeks. Non-unions were operated by excision of non-union, autogenous bone grafting and osteosynthesis by locking compression plating. Adequate fixation of non-union with bone grafting was achieved in all patients. All non-unions healed well at an average of 16 weeks (range 6-36 weeks). The mean length of follow-up was 120 weeks (range 60-250 weeks). The mean range of movements following healing of non-union was forward flexion of 140°, external rotation and internal rotation of 30° at shoulder and average fixed flexion deformity of 10° and flexion of 130° at elbow. Two patients had postoperative radial nerve palsy because of neuropraxia, which recovered in eight weeks. Three patient developed superficial infections at the iliac crest, which settled with antibiotics, dressings in 3 weeks time and two patients had some discomfort over the fibular graft harvest site. In all patients complete clinical and radiological union was achieved with satisfactory outcome in terms of relief of symptoms and functional improvement in the range of movements. The main points in surgical treatment were complete excision of non-union, correction of deformity, use of plenty of corticocancellous graft, furthermore the use of intramedullary fibula and osteosynthesis by long locking compression plating in different modes of fixation provided good to excellent results and

  5. A Novel Clinical-Simulated Suture Education for Basic Surgical Skill: Suture on the Biological Tissue Fixed on Standardized Patient Evaluated with Objective Structured Assessment of Technical Skill (OSATS) Tools. (United States)

    Shen, Zhanlong; Yang, Fan; Gao, Pengji; Zeng, Li; Jiang, Guanchao; Wang, Shan; Ye, Yingjiang; Zhu, Fengxue


    Clinical-simulated training has shown benefit in the education of medical students. However, the role of clinical simulation for surgical basic skill training such as suturing techniques remains unclear. Forty-two medical students were asked to perform specific suturing tasks at three stations with the different settings within four minutes (Station 1: Synthetic suture pad fixed on the bench, Station 2: Synthetic suture pad fixed on the standardized patient, Station 3: Pig skin fixed on the standardized patient); the OSATS (Objective Structured Assessment of Technical Skill) tool was used to evaluate the performance of students. A questionnaire was distributed to the students following the examination. Mean performance score of Station 3 was significant lower than that of Station 1 and 2 in the general performance including tissue handling, time, and motion. The suturing techniques of students at Station 2 and 3 were not as accurate as that at Station 1. Inappropriate tension was applied to the knot at Station 2 compared with Station 1 and 3. On the questionnaire, 93% of students considered clinical-simulated training of basic surgical skills was necessary and may increase their confidence in future clinical work as surgeons; 98% of students thought the assessment was more objective when OSATS tool was used for evaluation. Clinical simulation examination assessed with OSATS might throw a novel light on the education of basic surgical skills and may be worthy of wider adoption in the surgical education of medical students.

  6. Monte Carlo simulation of an anthropometric phantom used for calibrating in vivo K-XRF spectroscopy measurements of stable lead in bone. (United States)

    Lodwick, Camille J; Spitz, Henry B


    An anthropometric surrogate (phantom) of the human leg was defined in the constructs of the Monte Carlo N Particle (MCNP) code to predict the response when used in calibrating K x-ray fluorescence (K-XRF) spectrometry measurements of stable lead in bone. The predicted response compared favorably with measurements using the anthropometric phantom containing a tibia with increasing stable lead content. These benchmark measurements confirmed the validity of a modified MCNP code to accurately simulate K-XRF spectrometry measurements of stable lead in bone. A second, cylindrical leg phantom was simulated to determine whether the shape of the calibration phantom is a significant factor in evaluating K-XRF performance. Simulations of the cylindrical and anthropometric calibration phantoms suggest that a cylindrical calibration standard overestimates lead content of a human leg up to 4%. A two-way analysis of variance determined that phantom shape is a statistically significant factor in predicting the K-XRF response. These results suggest that an anthropometric phantom provides a more accurate calibration standard compared to the conventional cylindrical shape, and that a cylindrical shape introduces a 4% positive bias in measured lead values.

  7. Rehabilitation of a dentate mandible requiring a full arch rehabilitation. Immediate loading of a fixed complete denture on 8 implants placed with a bone-supported surgical computer-planned guide: a case report. (United States)

    Amorfini, Leonardo; Storelli, Stefano; Romeo, Eugenio


    The use of technologies that merge computerized tomography X-ray imaging and 3-dimensional (3D) planning software allow the surgeon to digitally elaborate on the computer the position, length, and diameter of every implant to be placed. Following this approach, the placement is guided in a 3D digital model, and the implants are placed in the final position avoiding eventual anatomic structures. In this case report, the patient's remaining mandibular teeth were extracted, and the patient received 8 implants with the help of a computer surgical guide. The case was planned using SimPlant and a bone-supported guide. Because of the high precision of the planning, it was possible to realize a provisional rehabilitation before the actual surgery. The planning allows placement of parallel implants to optimize the prosthetic procedure and outcome. An immediate provisional implant was fixed with a flow composite on the temporary abutments and then refined in the dental laboratory. The patient received the provisional rehabilitation the same day of the surgery. After 6 weeks of healing, the final impression was taken and the prosthesis was finalized with a computer-aided design/computer-aided manufacturing titanium full-arch screwed framework with composite veneering. A 6-month follow-up showed good integration of the prostheses and success of all 8 implants. The use of surgical computer-guided planning changes the surgeon's approach: whereas before the use of conventional guides permitted a certain degree of offset from what was planned, the use of computer guides allows the implant to be inserted in a far more precise way. It is obvious that careful planning is the key factor to avoid implant misplacement.

  8. Surgical outcomes of intermittent exotropia associated with concomitant hypertropia including simulated superior oblique palsy after horizontal muscles surgery only. (United States)

    Cho, Y A; Kim, S-H


    To investigate the clinical features and obtain guideline of treatment in intermittent exotropia associated with hypertropia including simulated superior oblique palsy. We retrospectively reviewed the charts of 93 patients of intermittent exotropia aligned with horizontal muscle surgery only, who showed hypertropia more than 2 PD in primary gaze before surgery and disappeared after surgery. They showed forveal extorsion and dysfunction of oblique muscles of 2+ or less and positive Bielschowsky head tilt test. The postoperative changes of deviation angle were analysed at postoperative 1 day, 6 months, and 1 year. Average amount of distant horizontal deviation in primary gaze was 32.3+/-9.58 (25-53) PD, hypertropia was 3.50+/-2.52 (2-14) PD. Average vertical deviation of ipsilateral (hypertropic eye) side was 8.8+/-4.63 PD and contralateral (hypotrophic eye) side was 4.0+/-4.77 PD in Bielschowsky head tilt test. Hypertropic eye was accorded with exotropic eye in 53.4%. After horizontal surgery, the amount of hypertropia was 1.2 PD at postoperative 1 day. On Bielschowsky head tilt test, hypertropia was almost eliminated showing 0.6 PD on the ipsilateral side and 0.2 PD on the contralateral eye at 1 month. This state was maintained up to postoperative 1 year. Small amount of hypertropia up to 14 PD in intermittent exotropia could be disappeared with horizontal muscle surgery only. However, careful examinations for head tilt history, fovea extorsion, oblique dysfunction, and Maddox rod test should be preceded to rule out true superior oblique palsy.

  9. Endotoxins in surgical instruments of hip arthroplasty


    Goveia, Vania Regina; Mendoza, Isabel Yovana Quispe; Guimarães, Gilberto Lima; Ercole, Flavia Falci; Couto, Bráulio Roberto Gonçalves Marinho; Leite, Edna Marilea Meireles; Stoianoff, Maria Aparecida Resende; Ferreira, José Antonio Guimarães


    Abstract OBJECTIVE To investigate endotoxins in sterilized surgical instruments used in hip arthroplasties. METHOD A descriptive exploratory study conducted in a public teaching hospital. Six types of surgical instruments were selected, namely: acetabulum rasp, femoral rasp, femoral head remover, chisel box, flexible bone reamer and femoral head test. The selection was based on the analysis of the difficulty in removing bone and blood residues during cleaning. The sample was made up of 60...

  10. Disruptive visions: surgical education. (United States)

    Satava, R M


    Technological change, decreased financial support for medical education, and social oversight (in the form of the "To Err Is Human" report, HIPPA, and reduced work hours) are forcing a rethinking of the traditional model of surgical education to improve patient safety. New approaches to evaluating surgical competence, such as objective assessment, in combination with new technologies, such as the Internet and surgical simulators, provide the tools to effect a revolution in surgical education and training. Competency based upon quantifiable criteria measures must replace the traditional subjective assessment. The implementation requires accurately defining the elements of training, establishing new quantifiable metrics, stringently measuring performance against criterion, and reporting outcomes throughout the career of a surgeon.

  11. Interprofessional Simulations Promote Knowledge Retention and Enhance Perceptions of Teamwork Skills in a Surgical-Trauma-Burn Intensive Care Unit Setting. (United States)

    George, Katie L; Quatrara, Beth

    The current state of health care encompasses highly acute, complex patients, managed with ever-changing technology. The ability to function proficiently in critical care relies on knowledge, technical skills, and interprofessional teamwork. Integration of these factors can improve patient outcomes. Simulation provides "hands-on" practice and allows for the integration of teamwork into knowledge/skill training. However, simulation can require a significant investment of time, effort, and financial resources. The Institute of Medicine recommendations from 2015 include "strengthening the evidence base for interprofessional education (IPE)" and "linking IPE with changes in collaborative behavior." In one surgical-trauma-burn intensive care unit (STBICU), no IPE existed. The highly acute and diverse nature of the patients served by the unit highlights the importance of appropriate training. This is heightened during critical event situations where patients deteriorate rapidly and the team intervenes swiftly. The aims of this study were to (1) evaluate knowledge retention and analyze changes in perceptions of teamwork among nurses and resident physicians in a STBICU setting after completion of an interprofessional critical event simulation and (2) provide insight for future interprofessional simulations (IPSs), including the ideal frequency of such training, associated cost, and potential effect on nursing turnover. A comparison-cohort pilot study was developed to evaluate knowledge retention and analyze changes in perceptions of teamwork. A 1-hour critical event IPS was held for nurses and resident physicians in a STBICU setting. A traumatic brain injury patient with elevated intracranial pressure, rapid deterioration, and cardiac arrest was utilized for the simulation scenario. The simulation required the team to use interventions to reduce elevated intracranial pressure and then perform cardiac resuscitation according to Advanced Cardiac Life Support guidelines. A

  12. Finite element analysis and CT-based structural rigidity analysis to assess failure load in bones with simulated lytic defects

    NARCIS (Netherlands)

    Anez-Bustillos, L.; Derikx, L.C.E.M.; Verdonschot, N.J.J.; Calderon, N.; Zurakowski, D.; Snyder, B.D.; Nazarian, A.; Tanck, E.J.M.


    There is an urgent need to improve the prediction of fracture risk for cancer patients with bone metastases. Pathological fractures that result from these tumors frequently occur in the femur. It is extremely difficult to determine the fracture risk even for experienced physicians. Although

  13. Surgical Audit

    African Journals Online (AJOL)


    Jan 6, 2010 ... A good way to describe the first surgical audits is that they were 'polite, restrained discussions'. This was the situation before the development of quality assurance in the business world. As this slowly infiltrated into the medical profession the discussions changed to more cri- teria based surgical audits.

  14. Human Emotion and Response in Surgery (HEARS): a simulation-based curriculum for communication skills, systems-based practice, and professionalism in surgical residency training. (United States)

    Larkin, Anne C; Cahan, Mitchell A; Whalen, Giles; Hatem, David; Starr, Susan; Haley, Heather-Lyn; Litwin, Demetrius; Sullivan, Kate; Quirk, Mark


    This study examines the development and implementation of a pilot human factors curriculum during a 2-year period. It is one component of a comprehensive 5-year human factors curriculum spanning core competencies of interpersonal and communication skills, systems-based practice, and professionalism and using low-and high-fidelity simulation techniques. Members of the Department of Surgery and the Center for Clinical Communication and Performance Outcomes jointly constructed a curriculum for PGY1 and PGY2 residents on topics ranging from challenging communication to time and stress management. Video demonstrations, triggers, and simulated scenarios involving acting patients were created by surgeons and medical educators. Pre- and postintervention measures were obtained for communication skills, perceived stress level, and teamwork. Communication skills were evaluated using a series of video vignettes. The validated Perceived Stress Scale and Teamwork and Patient Safety Attitudes survey were used. Residents' perceptions of the program were also measured. Twenty-seven PGY1 residents and 15 PGY2 residents participated during 2 years. Analyses of video vignette tests indicated significant improvement in empathic communication for PGY1 (t = 3.62, p = 0.001) and PGY2 (t = 5.00, p = 0.004). There were no significant changes to teamwork attitudes. Perceived levels of stress became considerably higher. PGY1 residents reported trying 1 to 3 strategies taught in the time management session, with 60% to 75% reporting improvement post-training. This unique and comprehensive human factors curriculum is shown to be effective in building communication competency for junior-level residents in the human and emotional aspects of surgical training and practice. Continued refinement and ongoing data acquisition and analyses are underway. Copyright 2010 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  15. Impact of surgical parathyroidectomy on chronic kidney disease-mineral and bone disorder (CKD-MBD - A systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Mugurel Apetrii

    Full Text Available For more than 6 decades, many patients with advanced chronic kidney disease (CKD have undergone surgical parathyroidectomy (sPTX for severe secondary hyperparathyroidism (SHPT mainly based historical clinical practice patterns, but not on evidence of outcome.We aimed in this meta-analysis to evaluate the benefits and harms of sPTX in patients with SHPT. We searched MEDLINE (inception to October 2016, EMBASE and Cochrane Library (through Issue 10 of 12, October 2016 and website (October 2016 without language restriction. Eligible studies evaluated patients reduced glomerular filtration rate (GFR, below 60 mL/min/1.73 m2 (CKD 3-5 stages with hyperparathyroidism who underwent sPTX. Reviewers working independently and in duplicate extracted data and assessed the risk of bias. The final analysis included 15 cohort studies, comprising 24,048 participants. Compared with standard treatment, sPTX significantly decreased all-cause mortality (RR 0.74 [95% CI, 0.66 to 0.83] in End Stage Kidney Disease (ESKD patients with biochemical and / or clinical evidence of SHPT. sPTX was also associated with decreased cardiovascular mortality (RR 0.59 [95% CI, 0.46 to 0.76] in 6 observational studies that included almost 10,000 patients. The available evidence, mostly observational, is at moderate risk of bias, and limited by indirect comparisons and inconsistency in reporting for some outcomes (eg. short term adverse events, including documented voice change or episodes of severe hypocalcaemia needing admission or long-term adverse events, including undetectable PTH levels, risk of fractures etc.. Taken together, the results of this meta-analysis would suggest a clinically significant beneficial effect of sPTX on all-cause and cardiovascular mortality in CKD patients with SHPT. However, given the observational nature of the included studies, the case for a properly conducted, independent randomised controlled trial comparing surgery with medical

  16. Measurements of simulated periodontal bone defects in inverted digital image and film-based radiograph: an in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Molon, Rafael Scaf; Morais Camillo, Juliana Aparecida Najarro Dearo; Ferreira, Mauricio Goncalves; Loffredo, Leonor Castro Monteiro; Scaf, Gulnara [Araraquara Dental School, Universidade Estadual Paulista, Sao Paulo (Brazil); Sakakura, Celso Eduardo [Barretos Dental School, Barretos Educational Fundation, Sao Paulo (Brazil)


    This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth. Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison. There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm (IC{sub 95%}:6.04-6.54) and 6.79 mm (IC{sub 95%}:6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64 mm(IC{sub 95%}:6.40-6.89) and 6.79 mm(IC{sub 95%}:6.45-7.11), respectively. The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss.

  17. Measurements of simulated periodontal bone defects in inverted digital image and film-based radiograph: an in vitro study

    International Nuclear Information System (INIS)

    Molon, Rafael Scaf; Morais Camillo, Juliana Aparecida Najarro Dearo; Ferreira, Mauricio Goncalves; Loffredo, Leonor Castro Monteiro; Scaf, Gulnara; Sakakura, Celso Eduardo


    This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth. Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison. There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm (IC 95% :6.04-6.54) and 6.79 mm (IC 95% :6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64 mm(IC 95% :6.40-6.89) and 6.79 mm(IC 95% :6.45-7.11), respectively. The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss.

  18. Simulations

    CERN Document Server

    Ngada, Narcisse


    The complexity and cost of building and running high-power electrical systems make the use of simulations unavoidable. The simulations available today provide great understanding about how systems really operate. This paper helps the reader to gain an insight into simulation in the field of power converters for particle accelerators. Starting with the definition and basic principles of simulation, two simulation types, as well as their leading tools, are presented: analog and numerical simulations. Some practical applications of each simulation type are also considered. The final conclusion then summarizes the main important items to keep in mind before opting for a simulation tool or before performing a simulation.

  19. Development and initial validation of a novel smoothed-particle hydrodynamics-based simulation model of trabecular bone penetration by metallic implants. (United States)

    Kulper, Sloan A; Fang, Christian X; Ren, Xiaodan; Guo, Margaret; Sze, Kam Y; Leung, Frankie K L; Lu, William W


    A novel computational model of implant migration in trabecular bone was developed using smoothed-particle hydrodynamics (SPH), and an initial validation was performed via correlation with experimental data. Six fresh-frozen human cadaveric specimens measuring 10 × 10 × 20 mm were extracted from the proximal femurs of female donors (mean age of 82 years, range 75-90, BV/TV ratios between 17.88% and 30.49%). These specimens were then penetrated under axial loading to a depth of 10 mm with 5 mm diameter cylindrical indenters bearing either flat or sharp/conical tip designs similar to blunt and self-tapping cancellous screws, assigned in a random manner. SPH models were constructed based on microCT scans (17.33 µm) of the cadaveric specimens. Two initial specimens were used for calibration of material model parameters. The remaining four specimens were then simulated in silico using identical material model parameters. Peak forces varied between 92.0 and 365.0 N in the experiments, and 115.5-352.2 N in the SPH simulations. The concordance correlation coefficient between experimental and simulated pairs was 0.888, with a 95%CI of 0.8832-0.8926, a Pearson ρ (precision) value of 0.9396, and a bias correction factor Cb (accuracy) value of 0.945. Patterns of bone compaction were qualitatively similar; both experimental and simulated flat-tipped indenters produced dense regions of compacted material adjacent to the advancing face of the indenter, while sharp-tipped indenters deposited compacted material along their peripheries. Simulations based on SPH can produce accurate predictions of trabecular bone penetration that are useful for characterizing implant performance under high-strain loading conditions. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  20. Deriving DICOM surgical extensions from surgical workflows (United States)

    Burgert, O.; Neumuth, T.; Gessat, M.; Jacobs, S.; Lemke, H. U.


    The generation, storage, transfer, and representation of image data in radiology are standardized by DICOM. To cover the needs of image guided surgery or computer assisted surgery in general one needs to handle patient information besides image data. A large number of objects must be defined in DICOM to address the needs of surgery. We propose an analysis process based on Surgical Workflows that helps to identify these objects together with use cases and requirements motivating for their specification. As the first result we confirmed the need for the specification of representation and transfer of geometric models. The analysis of Surgical Workflows has shown that geometric models are widely used to represent planned procedure steps, surgical tools, anatomical structures, or prosthesis in the context of surgical planning, image guided surgery, augmented reality, and simulation. By now, the models are stored and transferred in several file formats bare of contextual information. The standardization of data types including contextual information and specifications for handling of geometric models allows a broader usage of such models. This paper explains the specification process leading to Geometry Mesh Service Object Pair classes. This process can be a template for the definition of further DICOM classes.

  1. Evolution of surgical skills training (United States)

    Roberts, Kurt E; Bell, Robert L; Duffy, Andrew J


    Surgical training is changing: one hundred years of tradition is being challenged by legal and ethical concerns for patient safety, work hours restrictions, the cost of operating room time, and complications. Surgical simulation and skills training offers an opportunity to teach and practice advanced skills outside of the operating room environment before attempting them on living patients. Simulation training can be as straight forward as using real instruments and video equipment to manipulate simulated “tissue” in a box trainer. More advanced, virtual reality simulators are now available and ready for widespread use. Early systems have demonstrated their effectiveness and discriminative ability. Newer systems enable the development of comprehensive curricula and full procedural simulations. The Accreditation Council of Graduate Medical Education’s (ACGME) has mandated the development of novel methods of training and evaluation. Surgical organizations are calling for methods to ensure the maintenance of skills, advance surgical training, and to credential surgeons as technically competent. Simulators in their current form have been demonstrated to improve the operating room performance of surgical residents. Development of standardized training curricula remains an urgent and important agenda, particularly for minimal invasive surgery. An innovative and progressive approach, borrowing experiences from the field of aviation, can provide the foundation for the next century of surgical training, ensuring the quality of the product. As the technology develops, the way we practice will continue to evolve, to the benefit of physicians and patients. PMID:16718842

  2. Simulated radiographic bone and joint modeling from 3D ankle MRI: feasibility and comparison with radiographs and 2D MRI

    Energy Technology Data Exchange (ETDEWEB)

    Nordeck, Shaun M. [University of Texas Southwestern Medical College, Dallas, TX (United States); University of Texas Southwestern Medical Center, Musculoskeletal Radiology, Dallas, TX (United States); Koerper, Conrad E.; Adler, Aaron [University of Texas Southwestern Medical College, Dallas, TX (United States); Malhotra, Vidur; Xi, Yin [University of Texas Southwestern Medical Center, Musculoskeletal Radiology, Dallas, TX (United States); Liu, George T. [University of Texas Southwestern Medical Center, Orthopaedic Surgery, Dallas, TX (United States); Chhabra, Avneesh [University of Texas Southwestern Medical Center, Musculoskeletal Radiology, Dallas, TX (United States); University of Texas Southwestern Medical Center, Orthopaedic Surgery, Dallas, TX (United States)


    The purpose of this work is to simulate radiographs from isotropic 3D MRI data, compare relationship of angle and joint space measurements on simulated radiographs with corresponding 2D MRIs and real radiographs (XR), and compare measurement times among the three modalities. Twenty-four consecutive ankles were included, eight males and 16 females, with a mean age of 46 years. Segmented joint models simulating radiographs were created from 3D MRI data sets. Three readers independently performed blinded angle and joint space measurements on the models, corresponding 2D MRIs, and XRs at two time points. Linear mixed models and the intraclass correlation coefficient (ICC) was ascertained, with p values less than 0.05 considered significant. Simulated radiograph models were successfully created in all cases. Good agreement (ICC > 0.65) was noted among all readers across all modalities and among most measurements. Absolute measurement values differed between modalities. Measurement time was significantly greater (p < 0.05) on 2D versus simulated radiographs for most measurements and on XR versus simulated radiographs (p < 0.05) for nearly half the measurements. Simulated radiographs can be successfully generated from 3D MRI data; however, measurements differ. Good inter-reader and moderate-to-good intra-reader reliability was observed and measurements obtained on simulated radiograph models took significantly less time compared to measurements with 2D and generally less time than XR. (orig.)

  3. Bone scintigraphy in detection of bone invasion by oral carcinoma

    International Nuclear Information System (INIS)

    Higashi, Kotaro; Wakao, Hiromi; Ikuta, Hiroyuki; Kashima, Isamu; Everhart, F.R. Jr.


    Detecting osseous involvement is clinically important in the management of oral carcinoma. Thirty-one patients with osseous involvement due to oral carcinoma who underwent panoramic radiography and bone scintigraphy were evaluated retrospectively. Bone scintigraphy confirmed osseous involvement in all 31 (100%) of these patients. In 27 (87%) of 31 patients with osseous involvement, both the panoramic radiogram and bone scintigram were positive. In the remaining four patients (13%), bone scintigram was positive for mandibular or maxillary invasion, while panoramic radiogram was negative. There were no instances of an abnormal radiogram with a normal bone scintigram. These findings strongly suggest that bone scintigraphy is more sensitive than panoramic radiography in detecting osseous involvement of the mandible and maxilla due to oral carcinoma. Furthermore, bone scintigraphy was a critical pre-surgical tool in determining the extent of the osseous involvement. (author)

  4. Aneurysmal bone cysts

    Directory of Open Access Journals (Sweden)

    Rangachari P


    Full Text Available Back ground: Aneurysmal bone cysts have raised intra-cystic pressures which are dynamic and diagnostic in nature. Aneurysmal bone cysts could be diagnosed from other benign cystic lesions of bone by recording their intra-cystic pressures with a spinal manometer. Raised intra-cystic pressures in aneurysmal bone cysts are maintained as long as the periosteum over the cyst is intact even in those with pathological fractures. Even though its pathology is definite its aetio-pathology is not clear Method: Fourteen out of 16 radiologically benign cystic lesions of bone were subjected to intra-cystic pressure recordings with spinal manometer. Other two cysts had displaced unimpacted pathological fractures and so their intra-cystic pressures could not be recorded. All 16 cysts were subjected to histo-pathological examination to confirm their diagnosis and to find out for any pre-existing benign pathology. All the cysts were surgically treated. Results: Fourteen benign cystic lesions of bone were diagnosed as aneurysmal bone cysts preoperatively by recording raised intra-cystic pressures and confirmed by histo-pathology. In addition, histo-pathology revealed pre-existing benign pathology. All cysts were successfully treated surgically. Conclusions: Since, there is appreciable rise in intra-cystic dynamic pressures, the aneurysmal bone cyst is considered to be due to either sudden venous obstruction or arterio-venous shunt. Pre-operative intra-cystic pressure recordings help not only to diagnose aneurysmal bone cysts but also to assess the quantum of blood loss and its replacement during surgery.

  5. Pseudoanaplastic tumors of bone

    International Nuclear Information System (INIS)

    Bahk, Won-Jong; Mirra, Joseph M.


    To discuss the concept of pseudoanaplastic tumors of bone, which pathologically show hyperchromatism and marked pleomorphism with quite enlarged, pleomorphic nuclei, but with no to extremely rare, typical mitoses, and to propose guidelines for their diagnosis. From a database of 4,262 bone tumors covering from 1971 to 2001, 15 cases of pseudoanaplastic bone tumors (0.35% of total) were retrieved for clinical, radiographic and pathologic review. Postoperative follow-up after surgical treatment was at least 3 years and a maximum of 7 years. There were eight male and seven female patients. Their ages ranged from 10 to 64 years with average of 29.7 years. Pathologic diagnoses of pseudoanaplastic variants of benign bone tumors included: osteoblastoma (4 cases), giant cell tumor (4 cases), chondromyxoid fibroma (3 cases), fibrous dysplasia (2 cases), fibrous cortical defect (1 case) and aneurysmal bone cyst (1 case). Radiography of all cases showed features of a benign bone lesion. Six cases, one case each of osteoblastoma, fibrous dysplasia, aneurysmal bone cyst, chondromyxoid fibroma, giant cell tumor and osteoblastoma, were initially misdiagnosed as osteosarcoma. The remaining cases were referred for a second opinion to rule out sarcoma. Despite the presence of significant cytologic aberrations, none of our cases showed malignant behavior following simple curettage or removal of bony lesions. Our observation justifies the concept of pseudoanaplasia in some benign bone tumors as in benign soft tissue tumors, especially in their late evolutionary stage when bizarre cytologic alterations strongly mimic a sarcoma. (orig.)

  6. Pseudoanaplastic tumors of bone

    Energy Technology Data Exchange (ETDEWEB)

    Bahk, Won-Jong [Uijongbu St. Mary Hospital, The Catholic University of Korea, Department of Orthopaedic Surgery, Gyunggido, 480-821 (Korea); Mirra, Joseph M. [Orthopaedic Hospital, Orthopedic Oncology, Los Angeles, California (United States)


    To discuss the concept of pseudoanaplastic tumors of bone, which pathologically show hyperchromatism and marked pleomorphism with quite enlarged, pleomorphic nuclei, but with no to extremely rare, typical mitoses, and to propose guidelines for their diagnosis. From a database of 4,262 bone tumors covering from 1971 to 2001, 15 cases of pseudoanaplastic bone tumors (0.35% of total) were retrieved for clinical, radiographic and pathologic review. Postoperative follow-up after surgical treatment was at least 3 years and a maximum of 7 years. There were eight male and seven female patients. Their ages ranged from 10 to 64 years with average of 29.7 years. Pathologic diagnoses of pseudoanaplastic variants of benign bone tumors included: osteoblastoma (4 cases), giant cell tumor (4 cases), chondromyxoid fibroma (3 cases), fibrous dysplasia (2 cases), fibrous cortical defect (1 case) and aneurysmal bone cyst (1 case). Radiography of all cases showed features of a benign bone lesion. Six cases, one case each of osteoblastoma, fibrous dysplasia, aneurysmal bone cyst, chondromyxoid fibroma, giant cell tumor and osteoblastoma, were initially misdiagnosed as osteosarcoma. The remaining cases were referred for a second opinion to rule out sarcoma. Despite the presence of significant cytologic aberrations, none of our cases showed malignant behavior following simple curettage or removal of bony lesions. Our observation justifies the concept of pseudoanaplasia in some benign bone tumors as in benign soft tissue tumors, especially in their late evolutionary stage when bizarre cytologic alterations strongly mimic a sarcoma. (orig.)

  7. Simulation of ultrasonic wave propagation in anisotropic poroelastic bone plate using hybrid spectral/finite element method. (United States)

    Nguyen, Vu-Hieu; Naili, Salah


    This paper deals with the modeling of guided waves propagation in in vivo cortical long bone, which is known to be anisotropic medium with functionally graded porosity. The bone is modeled as an anisotropic poroelastic material by using Biot's theory formulated in high frequency domain. A hybrid spectral/finite element formulation has been developed to find the time-domain solution of ultrasonic waves propagating in a poroelastic plate immersed in two fluid halfspaces. The numerical technique is based on a combined Laplace-Fourier transform, which allows to obtain a reduced dimension problem in the frequency-wavenumber domain. In the spectral domain, as radiation conditions representing infinite fluid halfspaces may be exactly introduced, only the heterogeneous solid layer needs to be analyzed by using finite element method. Several numerical tests are presented showing very good performance of the proposed procedure. A preliminary study on the first arrived signal velocities computed by using equivalent elastic and poroelastic models will be presented. Copyright © 2012 John Wiley & Sons, Ltd.

  8. Compressive forces achieved in simulated equine third metacarpal bone lateral condylar fractures of varying fragment thickness with Acutrak Plus screw and 4.5 mm AO cortical screws. (United States)

    Lewis, Andrew J; Sod, Gary A; Burba, Daniel J; Mitchell, Colin F


    To compare compression pressure (CP) of 6.5 mm Acutrak Plus (AP) and 4.5 mm AO cortical screws (AO) when inserted in simulated lateral condylar fractures of equine 3rd metacarpal (MC3) bones. Paired in vitro biomechanical testing. Cadaveric equine MC3 bones (n=12 pair). Complete lateral condylar osteotomies were created parallel to the midsagittal ridge at 20, 12, and 8 mm axial to the epicondylar fossa on different specimens grouped accordingly. Interfragmentary compression was measured using a pressure sensor placed in the fracture plane before screw placement for fracture fixation. CP was acquired and mean values of CP for each fixation method were compared between the 6.5 mm (AP) and 4.5 mm (AO) for each group using a paired t-test within each fracture fragment thickness group with statistical significance set at Pfractures, especially complete fractures. Because interfragmentary compression plays a factor in the overall stability of a repair, it is recommended for use only in patients with thin lateral condyle fracture fragments, as the compression tends to decrease with an increase in thickness.

  9. Evaluation of Qualitative Changes in Simulated Periodontal Ligament and Alveolar Bone Using a Noncontact Electromagnetic Vibration Device with a Laser Displacement Sensor. (United States)

    Kobayashi, Hiroshi; Hayashi, Makoto; Yamaoka, Masaru; Yasukawa, Takuya; Ibi, Haruna; Ogiso, Bunnai


    Evaluating periodontal tissue condition is an important diagnostic parameter in periodontal disease. Noncontact electromagnetic vibration device (NEVD) was previously developed to monitor this condition using mechanical parameters. However, this system requires accelerometer on the target tooth. This study assessed application of laser displacement sensor (LDS) to NEVD without accelerometer using experimental tooth models. Tooth models consisted of cylindrical rod, a tissue conditioner, and polyurethane or polyurethane foam to simulate tooth, periodontal ligament, and alveolar bone, respectively. Tissue conditioner was prepared by mixing various volumes of liquid with powder. Mechanical parameters (resonant frequency, elastic modulus, and coefficient of viscosity) were assessed using NEVD with the following methods: Group A, measurement with accelerometer; Group B, measurement with LDS in the presence of accelerometer; and Group C, measurement with LDS in the absence of accelerometer. Mechanical parameters significantly decreased with increasing liquid volume. Significant differences were also observed between the polyurethane and polyurethane foam models. Meanwhile, no statistically significant differences were observed between Groups A and B; however, most mechanical parameters in Group C were significantly larger and more distinguishable than those of Groups A and B. LDS could measure mechanical parameters more accurately and clearly distinguished the different periodontal ligament and alveolar bone conditions.

  10. Evaluation of Qualitative Changes in Simulated Periodontal Ligament and Alveolar Bone Using a Noncontact Electromagnetic Vibration Device with a Laser Displacement Sensor

    Directory of Open Access Journals (Sweden)

    Hiroshi Kobayashi


    Full Text Available Evaluating periodontal tissue condition is an important diagnostic parameter in periodontal disease. Noncontact electromagnetic vibration device (NEVD was previously developed to monitor this condition using mechanical parameters. However, this system requires accelerometer on the target tooth. This study assessed application of laser displacement sensor (LDS to NEVD without accelerometer using experimental tooth models. Tooth models consisted of cylindrical rod, a tissue conditioner, and polyurethane or polyurethane foam to simulate tooth, periodontal ligament, and alveolar bone, respectively. Tissue conditioner was prepared by mixing various volumes of liquid with powder. Mechanical parameters (resonant frequency, elastic modulus, and coefficient of viscosity were assessed using NEVD with the following methods: Group A, measurement with accelerometer; Group B, measurement with LDS in the presence of accelerometer; and Group C, measurement with LDS in the absence of accelerometer. Mechanical parameters significantly decreased with increasing liquid volume. Significant differences were also observed between the polyurethane and polyurethane foam models. Meanwhile, no statistically significant differences were observed between Groups A and B; however, most mechanical parameters in Group C were significantly larger and more distinguishable than those of Groups A and B. LDS could measure mechanical parameters more accurately and clearly distinguished the different periodontal ligament and alveolar bone conditions.

  11. The effect of fasting on surgical performance

    DEFF Research Database (Denmark)

    Schefte, David Fenger; Rosenstock, Steffen Jais


    BACKGROUND: It is unknown whether fasting has any impact on surgical performance. This simulator-based study investigates whether fasting affects surgical performance. METHODS: Twelve healthy medical students [seven women, mean age 26.5 years (range 23-34)] with no prior experience with surgical...... simulators underwent a short course introduction to the LapSim(®) simulator. After having reached a predefined level, the participants performed five simulated salpingectomies on the LapSim(®) simulator 5-30 days after the initial introduction. The procedures took place at 9 a.m. and 2 p.m. after fasting...... in the longitudinal axis with the left hand. CONCLUSION: The simulator-based study suggests that 17 h of fasting does not deteriorate surgical performance. Further studies on the effect of fasting on surgical performance are needed....

  12. Simulated radiographic bone and joint modeling from 3D ankle MRI: feasibility and comparison with radiographs and 2D MRI. (United States)

    Nordeck, Shaun M; Koerper, Conrad E; Adler, Aaron; Malhotra, Vidur; Xi, Yin; Liu, George T; Chhabra, Avneesh


    The purpose of this work is to simulate radiographs from isotropic 3D MRI data, compare relationship of angle and joint space measurements on simulated radiographs with corresponding 2D MRIs and real radiographs (XR), and compare measurement times among the three modalities. Twenty-four consecutive ankles were included, eight males and 16 females, with a mean age of 46 years. Segmented joint models simulating radiographs were created from 3D MRI data sets. Three readers independently performed blinded angle and joint space measurements on the models, corresponding 2D MRIs, and XRs at two time points. Linear mixed models and the intraclass correlation coefficient (ICC) was ascertained, with p values less than 0.05 considered significant. Simulated radiograph models were successfully created in all cases. Good agreement (ICC > 0.65) was noted among all readers across all modalities and among most measurements. Absolute measurement values differed between modalities. Measurement time was significantly greater (p 3D MRI data; however, measurements differ. Good inter-reader and moderate-to-good intra-reader reliability was observed and measurements obtained on simulated radiograph models took significantly less time compared to measurements with 2D and generally less time than XR.

  13. Mastoidectomy performance assessment of virtual simulation training using final-product analysis

    DEFF Research Database (Denmark)

    Andersen, Steven A W; Cayé-Thomasen, Per; Sørensen, Mads S


    in virtual simulation and traditional dissection training. STUDY DESIGN: Prospective trial with blinding. METHODS: A total of 34 novice residents performed a mastoidectomy on the Visible Ear Simulator and on a cadaveric temporal bone. Two blinded senior otologists assessed the final-product performance using...... version of a validated final-product performance assessment tool can be used to assess mastoidectomy on virtual temporal bones. Performance assessment of virtual mastoidectomy could potentially save the use of cadaveric temporal bones for more advanced training when a basic level of competency......OBJECTIVES/HYPOTHESIS: The future development of integrated automatic assessment in temporal bone virtual surgical simulators calls for validation against currently established assessment tools. This study aimed to explore the relationship between mastoidectomy final-product performance assessment...

  14. CT pre-operative planning of a new semi-implantable bone conduction hearing device

    Energy Technology Data Exchange (ETDEWEB)

    Law, Eric K.C.; Bhatia, Kunwar S.S. [Prince of Wales Hospital, The Chinese University of Hong Kong, Department of Imaging and Interventional Radiology, Hong Kong, SAR (China); Tsang, Willis S.S.; Tong, Michael C.F. [Prince of Wales Hospital, The Chinese University of Hong Kong, Department of Otorhinolaryngology, Head and Neck Surgery, Hong Kong, SAR (China); Shi, Lin [The Chinese University of Hong Kong, Department of Medicine and Therapeutics, Hong Kong, SAR (China); The Chinese University of Hong Kong, Chow Yuk Ho Technology Center for Innovative Medicine, Hong Kong, SAR (China)


    Accommodating a novel semi-implantable bone conduction hearing device within the temporal bone presents challenges for surgical planning. This study describes the utility of CT in pre-operative assessment of such an implant. Retrospective review of pre-operative CT, clinical and surgical records of 16 adults considered for device implantation. Radiological suitability was assessed on CT using 3D simulation software. Antero-posterior (AP) dimensions of the mastoid bone and minimum skull thickness were measured. CT planning results were correlated with operative records. Eight and five candidates were suitable for device placement in the transmastoid and retrosigmoid positions, respectively, and three were radiologically unsuitable. The mean AP diameter of the mastoid cavity was 14.6 mm for the transmastoid group and 4.6 mm for the retrosigmoid group (p < 0.05). Contracted mastoid and/or prior surgery were predisposing factors for unsuitability. Four transmastoid and five retrosigmoid positions required sigmoid sinus/dural depression and/or use of lifts due to insufficient bone capacity. A high proportion of patients being considered have contracted or operated mastoids, which reduces the feasibility of the transmastoid approach. This finding combined with the complex temporal bone geometry illustrates the importance of careful CT evaluation using 3D software for precise device simulation. (orig.)

  15. Mechanisms of Guided Bone Regeneration: A Review (United States)

    Liu, Jie; Kerns, David G


    Post-extraction crestal bone resorption is common and unavoidable which can lead to significant ridge dimensional changes. To regenerate enough bone for successful implant placement, Guided Bone Regeneration (GBR) is often required. GBR is a surgical procedure that uses barrier membranes with or without particulate bone grafts or/and bone substitutes. There are two approaches of GBR in implant therapy: GBR at implant placement (simultaneous approach) and GBR before implant placement to increase the alveolar ridge or improve ridge morphology (staged approach). Angiogenesis and ample blood supply play a critical role in promoting bone regeneration. PMID:24894890

  16. Bone Cancer (United States)

    Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another ... more common. There are three types of bone cancer: Osteosarcoma - occurs most often between ages 10 and ...


    African Journals Online (AJOL)

    SURGICAL ANATOMY. Rare high origin of the radial artery: a bilateral, symmetrical ease. I. O. ()koro and B. C. J iburum. Department of Anatomy, College of Medicine, lrno State University, Owerri, Nigeria. Reprint requests to: Dr I. O. 0k0r0, Department of Anatomy, [mo State University, P. M. B. 2000. Owerri, Nigeria.


    African Journals Online (AJOL)

    Conclusion:Foraminotomy with or without discectomy is a simple posterior surgical approach to T B spine with good neurological outcome. It is adapted to our ... of the spine also referred to as. (HIV/AIDS) further challenge the outcome. These .... treatment; or for spinal cord or nerve root from 2 weeks depending on patient ...

  19. Attracting students to surgical careers: preclinical surgical experience. (United States)

    Antiel, Ryan M; Thompson, Scott M; Camp, Christopher L; Thompson, Geoffrey B; Farley, David R


    Along with a decline in interest in general surgery among United States medical school graduates, reports indicate a decrease in the amount of time students are spending on their surgical clerkship. In an effort to offer early exposure to general surgery as well as to equip students with the basic surgical skills that will enhance their third-year clerkship experience, we developed a preclinical surgical experience. Students were surveyed to determine whether the surgical selective changed student level of comfort with basic surgical skills. Surveys were administered, preexperience and postexperience to the medical students enrolled in the surgery selective. The students were asked to rate their comfort level with 12 unique surgical skills. Comfort with the task was evaluated using a 10-point Likert scale. Analyses were conducted to evaluate the impact of the surgical experience on student comfort levels with the surgical skills. The self-reported comfort levels of students increased significantly after the experience in all 12 areas. The greatest change in comfort level (greater than or equal to mean difference of 4) occurred in the surgical technique categories: knot tying (mean difference: 4.9, p < 0.0001), suturing (mean difference: 4.85, p < 0.0001), correctly making an incision (mean difference: 4.95, p < 0.0001), using a needle driver (mean difference: 5.35, p < 0.0001), holding pickups (mean difference: 4.6, p < 0.0001), use of laparoscopic instruments (mean difference: 4.8, p < 0.0001), and use of surgical simulators (mean difference: 6.0, p < 0.0001). Our preclinical surgical experience serves as a model of an effective modality providing early exposure to general surgery. The experience provides trainees with basic surgical skills well before they begin their third-year clerkships. Copyright © 2012 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  20. Low Bone Density (United States)

    ... Bone Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your bone ... to people with normal bone density. Detecting Low Bone Density A bone density test will determine whether ...

  1. Surgical Navigation

    DEFF Research Database (Denmark)

    Azarmehr, Iman; Stokbro, Kasper; Bell, R. Bryan


    body removal, respectively. The average technical system accuracy and intraoperative precision reported were less than 1 mm and 1 to 2 mm, respectively. In general, SN is reported to be a useful tool for surgical planning, execution, evaluation, and research. The largest numbers of studies and patients......Purpose: This systematic review investigates the most common indications, treatments, and outcomes of surgical navigation (SN) published from 2010 to 2015. The evolution of SN and its application in oral and maxillofacial surgery have rapidly developed over recent years, and therapeutic indications...... surgery, skull-base surgery, and foreign body removal were the areas of interests. Results: The search generated 13 articles dealing with traumatology; 5, 6, 2, and 0 studies were found that dealt with the topics of orthognathic surgery, cancer and reconstruction surgery, skull-base surgery, and foreign...

  2. Porous surface modified bioactive bone cement for enhanced bone bonding.

    Directory of Open Access Journals (Sweden)

    Qiang He

    Full Text Available Polymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth.The porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant-bone interface was also investigated by push-out tests.The modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony defect.Our findings suggested a new bioactive

  3. Temporal bone meningiomas. (United States)

    Vrionis, F D; Robertson, J H; Gardner, G; Heilman, C B


    Meningiomas involving the temporal bone may originate from arachnoid cell nests present within the temporal bone (intratemporal), but more frequently originate from arachnoid cell nests of the posterior or middle cranial fossa with secondary invasion of the TB (extratemporal). In this study, we retrospectively reviewed the charts of 13 patients with meningiomas involving the temporal bone who underwent surgery. Tumors of the posterior fossa with only temporal bone hyperostosis, but without invasion, were excluded. Patients presented primarily with otologic symptoms and signs. The tumors originated in the temporal bone (5/13), jugular foramen (4/13), petroclival region (2/13), the asterion (1/13) or the internal auditory meatus (1/13). All of the intratemporal meningiomas had the radiological appearance of en-plaque menigiomas. The tumor extended into the middle ear (11/13), eustachian tube (5/13), and/or the labyrinth (3/13). A gross total resection was achieved in 11 patients and a subtotal resection in 2 patients. The lower cranial nerves were infiltrated by tumor in 4 patients, and were sacrificed. At a mean follow-up of approximately 6 years, 12 patients are currently alive and doing well and 1 died from tumor progression. Six patients showed tumor recurrence and were reoperated on (5/6) or followed conservatively (1/6). Surgical treatment of temporal bone meningiomas is associated with high recurrence rate due to indiscreet tumor margins. Combined surgical approaches (temporal craniotomy and mastoidectomy) by neurosurgical and otological teams are recommended for meningiomas originating in the temporal bone.

  4. Effects of atomic-level nano-structured hydroxyapatite on adsorption of bone morphogenetic protein-7 and its derived peptide by computer simulation


    Wang, Qun; Wang, Menghao; Lu, Xiong; Wang, Kefeng; Fang, Liming; Ren, Fuzeng; Lu, Guoming


    Hydroxyapatite (HA) is the principal inorganic component of bones and teeth and has been widely used as a bone repair material because of its good biocompatibility and bioactivity. Understanding the interactions between proteins and HA is crucial for designing biomaterials for bone regeneration. In this study, we evaluated the effects of atomic-level nano-structured HA (110) surfaces on the adsorption of bone morphogenetic protein-7 (BMP-7) and its derived peptide (KQLNALSVLYFDD) using molecu...

  5. Endotoxins in surgical instruments of hip arthroplasty

    Directory of Open Access Journals (Sweden)

    Vania Regina Goveia


    Full Text Available Abstract OBJECTIVE To investigate endotoxins in sterilized surgical instruments used in hip arthroplasties. METHOD A descriptive exploratory study conducted in a public teaching hospital. Six types of surgical instruments were selected, namely: acetabulum rasp, femoral rasp, femoral head remover, chisel box, flexible bone reamer and femoral head test. The selection was based on the analysis of the difficulty in removing bone and blood residues during cleaning. The sample was made up of 60 surgical instruments, which were tested for endotoxins in three different stages. The EndosafeTM Gel-Clot LAL (Limulus Amebocyte Lysate method was used. RESULT There was consistent gel formation with positive analysis in eight instruments, corresponding to 13.3%, being four femoral rasps and four bone reamers. CONCLUSION Endotoxins in quantity ≥0.125 UE/mL were detected in 13.3% of the instruments tested.

  6. An open source software tool to assign the material properties of bone for ABAQUS finite element simulations. (United States)

    Pegg, Elise C; Gill, Harinderjit S


    A new software tool to assign the material properties of bone to an ABAQUS finite element mesh was created and compared with Bonemat, a similar tool originally designed to work with Ansys finite element models. Our software tool (py_bonemat_abaqus) was written in Python, which is the chosen scripting language for ABAQUS. The purpose of this study was to compare the software packages in terms of the material assignment calculation and processing speed. Three element types were compared (linear hexahedral (C3D8), linear tetrahedral (C3D4) and quadratic tetrahedral elements (C3D10)), both individually and as part of a mesh. Comparisons were made using a CT scan of a hemi-pelvis as a test case. A small difference, of -0.05kPa on average, was found between Bonemat version 3.1 (the current version) and our Python package. Errors were found in the previous release of Bonemat (version 3.0 downloaded from during calculation of the quadratic tetrahedron Jacobian, and conversion of the apparent density to modulus when integrating over the Young׳s modulus field. These issues caused up to 2GPa error in the modulus assignment. For these reasons, we recommend users upgrade to the most recent release of Bonemat. Processing speeds were assessed for the three different element types. Our Python package took significantly longer (110s on average) to perform the calculations compared with the Bonemat software (10s). Nevertheless, the workflow advantages of the package and added functionality makes 'py_bonemat_abaqus' a useful tool for ABAQUS users. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Method of adhering bone to a rigid substrate using a graphite fiber reinforced bone cement (United States)

    Knoell, A. C.; Maxwell, H. G. (Inventor)


    A method is described for adhering bone to the surface of a rigid substrate such as a metal or resin prosthesis using an improved surgical bone cement. The bone cement has mechanical properties more nearly matched to those of animal bone and thermal curing characteristics which result in less traumatization of body tissues and comprises a dispersion of short high modulus graphite fibers within a bonder composition including polymer dissolved in reactive monomer such as polymethylmethacrylate dissolved in methylmethacrylate monomer.

  8. Vulnerary Factors to Improve Bone Healing

    National Research Council Canada - National Science Library

    Hollinger, Jeffrey O


    The objective for the work was to process rabbit bone specimens from the Institute of Surgical Research, foliwed by sectioning and staining of the samples No patents application were filed The rabbit...

  9. Simulation

    DEFF Research Database (Denmark)

    Gould, Derek A; Chalmers, Nicholas; Johnson, Sheena J


    Recognition of the many limitations of traditional apprenticeship training is driving new approaches to learning medical procedural skills. Among simulation technologies and methods available today, computer-based systems are topical and bring the benefits of automated, repeatable, and reliable...... performance assessments. Human factors research is central to simulator model development that is relevant to real-world imaging-guided interventional tasks and to the credentialing programs in which it would be used....

  10. Tophi - surgical treatment. (United States)

    Słowińska, Iwona; Słowiński, Radosław; Rutkowska-Sak, Lidia


    Gout is an inflammatory joint disease associated with deposition of monosodium urate crystals in the bones forming the joints, in periarticular tissues and in other organs. The disease is one of the most frequent causes of disability. This paper presents the case of a 57-year-old male patient treated for generalised gout. A "clinical mask" suggesting another disease was the cause of making the correct diagnosis only six years after the occurrence of the first manifestations. The patient, with high values of inflammatory markers, severe pain and advanced joint destruction, was given an aggressive anti-inflammatory treatment. The unsatisfactory effect of the conservative treatment forced the authors to perform surgical resection of the gouty nodules in the hands. After several operations the function of the hand joints operated on, appearance of the hands and the quality of the patient's life improved significantly.

  11. Bone disease in primary hyperparathyroidism (United States)

    Bandeira, Francisco; Cusano, Natalie E.; Silva, Barbara C.; Cassibba, Sara; Almeida, Clarissa Beatriz; Machado, Vanessa Caroline Costa; Bilezikian, John P.


    Bone disease in severe primary hyperparathyroidism (PHPT) is described classically as osteitis fibrosa cystica (OFC). Bone pain, skeletal deformities and pathological fractures are features of OFC. Bone mineral density is usually extremely low in OFC, but it is reversible after surgical cure. The signs and symptoms of severe bone disease include bone pain, pathologic fractures, proximal muscle weakness with hyperreflexia. Bone involvement is typically characterized as salt-and-pepper appearance in the skull, bone erosions and bone resorption of the phalanges, brown tumors and cysts. In the radiography, diffuse demineralization is observed, along with pathological fractures, particularly in the long bones of the extremities. In severe, symptomatic PHPT, marked elevation of the serum calcium and PTH concentrations are seen and renal involvement is manifested by nephrolithiasis and nephrocalcinosis. A new technology, recently approved for clinical use in the United States and Europe, is likely to become more widely available because it is an adaptation of the lumbar spine DXA image. Trabecular bone score (TBS) is a gray-level textural analysis that provides an indirect index of trabecular microarchitecture. Newer technologies, such as high-resolution peripheral quantitative computed tomography (HR-pQCT), have provided further understanding of the microstructural skeletal features in PHPT. PMID:25166047

  12. Surgical endodontics. (United States)

    Carrotte, P


    Root canal treatment usually fails because infection remains within the root canal. An orthograde attempt at re-treatment should always be considered first. However, when surgery is indicated, modern microtechniques coupled with surgical magnification will lead to a better prognosis. Careful management of the hard and soft tissues is essential, specially designed ultrasonic tips should be used for root end preparation which should ideally be sealed with MTA. All cases should be followed up until healing is seen, or failure accepted, and should form a part of clinical audit.

  13. Mandibular reconstruction using bone allografts

    International Nuclear Information System (INIS)

    Chang Joon Yim


    Further understanding of bone healing mechanisms, bone physiology and bone biology, transplantation immunology, and development of Tissue Banking procedures has enabled oral and maxillofacial surgeons to reconstruct even the most difficult bony defects successfully with the preserved allogeneic bone implant. Although it had been known that bone allografts were clinically effective, its application has not been widespread until the reports of Inclan (I 942), Hyatt and Butler (I 950), and Wilson (I 95 1). Tissue Banking provides the surgeon with a readily available, relatively inexpensive, and relatively safe selection of allogeneic bone for clinical use. Now autogenous bone and allogeneic bone implants present a wide variety of surgical options to surgeons, whether used separately or in combination. The surgeons are able to make judicious and fruitful choices, only with a thorough knowledge of the above-mentioned biological principles and skillful techniques. Many kinds of bone grafting techniques have been tried for reconstructing defective osseous tissues of the oral and maxillofacial region, though they have varying degrees of success. The osseous defects which require grafting include those of various size, shape, position, or amount. Unlike autogenous grafts, whose function is to provide osteogenic cells, allografts are purely passive, offering only a matrix for the inductive phase of bone healing. The condition of the recipient bed is of primary importance, because the host must produce all of the essential elements for the bone allograft to become incorporated. Depending on the processing methods of the allogeneic bone, the bone graft materials have different qualities, different healing potentials and different indications. Proper selection of grafts and surgical techniques requires an understanding of graft immunology and the mechanisms of graft healing. The surgeons should know about the biological principles to raise the clinical success rate

  14. Maxillary bone myxoma. (United States)

    Zainine, R; Mizouni, H; El Korbi, A; Beltaief, N; Sahtout, S; Besbes, G


    Maxillary bone myxoma is a rare benign mesenchymal tumor, slow-growing but locally aggressive. Pathogenesis remains disputed. To study the clinical, radiological and histological features and treatment of maxillary myxoma, based on a pediatric case report. An infant of two and a half months presented with endonasal tumor extending to ethmoid. Surgical excision was performed on an endonasal approach. Myxoma was diagnosed by histologic examination of the surgical specimen, whereas initial biopsy had suggested fibrous dysplasia. No recurrence was observed after two and a half years' surveillance. Positive diagnosis of maxillary myxoma is histological. Treatment is primarily surgical. Strict long-term surveillance is required because of the high risk of recurrence. Copyright © 2013. Published by Elsevier Masson SAS.

  15. Bone marrow aspiration (United States)

    Iliac crest tap; Sternal tap; Leukemia - bone marrow aspiration; Aplastic anemia - bone marrow aspiration; Myelodysplastic syndrome - bone marrow aspiration; Thrombocytopenia - bone marrow aspiration; Myelofibrosis - bone marrow aspiration

  16. Evolving Educational Techniques in Surgical Training. (United States)

    Evans, Charity H; Schenarts, Kimberly D


    Training competent and professional surgeons efficiently and effectively requires innovation and modernization of educational methods. Today's medical learner is quite adept at using multiple platforms to gain information, providing surgical educators with numerous innovative avenues to promote learning. With the growth of technology, and the restriction of work hours in surgical education, there has been an increase in use of simulation, including virtual reality, robotics, telemedicine, and gaming. The use of simulation has shifted the learning of basic surgical skills to the laboratory, reserving limited time in the operating room for the acquisition of complex surgical skills". Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Simulation

    CERN Document Server

    Ross, Sheldon


    Ross's Simulation, Fourth Edition introduces aspiring and practicing actuaries, engineers, computer scientists and others to the practical aspects of constructing computerized simulation studies to analyze and interpret real phenomena. Readers learn to apply results of these analyses to problems in a wide variety of fields to obtain effective, accurate solutions and make predictions about future outcomes. This text explains how a computer can be used to generate random numbers, and how to use these random numbers to generate the behavior of a stochastic model over time. It presents the statist

  18. Traumatic bone cyst suggestive of large apical periodontitis. (United States)

    Rodrigues, Cleomar Donizeth; Estrela, Carlos


    This case report shows the importance of establishing the correct diagnosis to provide the appropriate treatment options The traumatic bone cyst is a pseudocyst, usually asymptomatic and found by a routine radiographic examination. Unicystic radiolucency is almost always observed, which can involve the periradicular area of teeth, simulating an inflammatory lesion of endodont