Surgical navigation systems enable surgeons to carry out surgical interventions more accurately and less invasively, by tracking the
Introduction. Ilizarov fixators are reliant on tensioned fine wires for stability. The tension in the wires is generated using specific tensioning devices. Loss of wire tension over time may lead of loss a stability and complications. A series of in vitro experiments were undertaken to explore wire tensioner accuracy, the impact of fixation bolt torque and initial tension on loss of tension in ilizarov constructs under static and dynamic loads. Materials & Methods. Medical grade materials were applied to a synthetic bone analogue using
Demographic changes will increase the number of surgical procedures in the next years. Therefore, quality assurance of clinical processes, such as the reprocessing of
INTRODUCTION. Due to increasing interest into taper corrosion observed primarily in hip arthroplasty devices with modular tapers, efforts towards characterizing the corrosion byproducts are prevalent in the literature [1–4]. As a result of this motivation, several studies postulate cellular induced corrosion due to the presence of remarkable features in the regions near taper junction regions and articulating surfaces [3–5]. Observations made on explanted devices from a retrieval database as well as laboratory tests have led to the alternative proposal of electrocautery-electrosurgery damage as the cause of these features. These
Introduction. In hip arthroplasty, it has been shown that assembly of the femoral head onto the stem remains a non-standardized practice and differs between surgeons [1]. Pennock et al. determined by altering mechanical conditions during seating there was a direct effect on the taper strength [2]. Furthermore, Mali et al. demonstrated that components assembled with a lower assembly load had increased fretting currents and micromotion at the taper junction during cyclic testing [3]. This suggests overall performance may be affected by head assembly method. The purpose of this test was to perform controlled bench top studies to determine the influence of impaction force and compliance of support structure (or damping) on the initial stability of the taper junction. Materials and Methods. Test Specimens. Testing was performed on 36mm +5mm CoCr heads combined with prototype Ti6Al4V locking taper analogs both machined with approximately a 5.67º taper angle. To minimize sample variation, the locking taper analogs were dimensionally matched with CoCr femoral heads to maintain a uniform angle difference. Prior to testing, samples were cleaned with isopropanol and allowed to dry. Effect of Peak Force Magnitude. Testing was performed on a rigid setup where a 10N preload was applied to the femoral head axially. Heads were assembled with loads ranging from 2kN–10kN using an impaction tower and seating loads were recorded at a collection rate of 273kHz. After assembly, tensile loads were applied until the taper junction was fully disassembled and distraction loads were recorded at a collection rate of 500Hz. Effect of Damping. 40 durometer rubber pads were placed underneath the trunnions as well as to the striking surface of the impaction tower to simulate compliance in the supporting structure and the
Purpose. When we perform total knee arthroplasty (TKA), the accurate osteotomy and implant setting is important as follows to improve long-term results. As means to perform osteotomy exactly, patient specific
Total joint arthroplasty (TJA) is one of the most successful procedures in orthopaedics. Despite the excellent clinical and functional results, periprosthetic joint infection (PJI) following TJA is a feared complication. For instance, the reported PJI rate after primary total knee arthroplasty is about 0.5–1.9%. In general, prevention of periprosthetic joint and surgical site infections is of utmost importance. This can be reduced by strict antisepsis, adequate sterilization of the
Over the past decades, computer-aided navigation system has experienced tremendous development for minimising the risks and improving the precision of the surgery. Nowadays, some commercially-available and self-developed surgical navigation systems have already been tested and proved successfully for clinical applications. However, all of these systems use computer screen to render the navigation information such as the real-time position and orientation of the
Total hip replacement in Germany has been performed in 227293 cases in 2015 and tendency is increasing. Although it is a standard intervention, freehand positioning of cup protheses has frequently poor accuracy. Image-based and image-free navigation systems improve the accuracy but most of them provide target positions as alphanumeric values on large-size screens beneath the patient site. In this case the surgeon always has to move his head frequently to change his eye-focus between incision and display to capture the target values. Already published studies using e.g. IPod-based displays or LED ring displays, show the chance for improvement by alternative approaches. Therefore, we propose a novel solution for an instrument-mounted small display in order to visualise intuitive instructions for instrument guidance directly in the viewing area of the surgeon. For this purpose a solution consisting of a MicroView OLED display with integrated Arduino microcontroller, equipped with a Bluetooth interface as well as a battery has been developed. We have used an optical tracking system and our custom-designed navigation software to track
In the UK, the NHS generates an estimated 25 megatonnes of carbon dioxide equivalents (4% to 5% of the nation’s total carbon emissions) and produces over 500,000 tonnes of waste annually. There is limited evidence demonstrating the principles of sustainability and its benefits within orthopaedic surgery. The primary aim of this study was to analyze the environmental impact of orthopaedic surgery and the environmentally sustainable initiatives undertaken to address this. The secondary aim of this study was to describe the barriers to making sustainable changes within orthopaedic surgery. A literature search was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines through EMBASE, Medline, and PubMed libraries using two domains of terms: “orthopaedic surgery” and “environmental sustainability”.Aims
Methods
In performing posterior cruciate ligament- retaining total knee arthroplasty (CR-TKA), the original
Computer assisted surgery is becoming more frequently used in the medical world. Navigation of
Introduction. Revision Total Hip Arthroplasties (THA) have a significantly higher failure rate than primary THA's and the most common cause is aseptic loosening of the cup. To reduce this incidence of loosening various porous metal implants with a rough surface and a porous architecture have been developed which are said to increase early osteointegration. However, for successful osteointegration a minimal micromotion between the implant and the host bone (primary stability) is beneficial. It has not been previously determined if the primary stability for the new Gription® titanium cup differs from that of the old Porocoat® titanium cup. Material and Methods. In 10 cadaveric pelvises, divided into 20 hemipelvises, bilateral THA's were performed by an experienced surgeon (RGB) following the implant manufacturer's instructions and with the original
Introduction. Dislocation due to suboptimal cup positioning is a devastating complication in the early phase after total hip arthroplasty. Malpositioning can also result in other mechanical complications like subluxation, edge loading, increased debris, surface damage or squeaking in ceramic-on-ceramic hips. Preventing at least some of these complications in younger and more active patients is of paramount interest for the individual patient and for the society since optimized component orientation is an important determinant to reduce such risks and to further increase longevity of the implant. This study reports on two new
INTRODUCTION. Total knee replacement is mostly done with alignment rods in order to achieve a proper Varus / Valgus alignement. Other techniques are computer assisted navigation or MRI based preoperative planning. iASSIST™ is a computer assisted stereotaxic
In recent years 3D preoperative planning has become increasingly popular with orthopaedic surgeons. One technique that has shown to be successful in transferring this preoperative plan to the operating room is based on surgical templates that guide various
We share our experiences in designing a complete simulator prototype and provide the technological basis to determine whether an immersive medical training environment for vertebroplasty is successful. In our study, the following key research contributions were realised: (1) the effective combination of a virtual reality surgical simulator and a computerised mannequin in designing a novel training setup for medical education, and (2) based on a user-study, the quantitative evaluation through surgical workflow and crisis simulation in proving the face validity of our immersive medical training environment. Medical simulation platforms intend to assist and support surgical trainees by enhancing their skills in a virtual environment. This approach to training is consistent with an important paradigm shift in medical education that has occurred over the past decade. Surgical trainees have traditionally learned interventions on patients under the supervision of a senior physician in what is essentially an apprenticeship model. In addition to exposing patients to some risk, this tends to be a slow and inherently subjective process that lacks objective, quantitative assessment of performance. By proposing our immersive medical simulator we offer the first shared experimental platform for education researchers to design, implement, test, and compare vertebroplasty training methods. We collected feedback from two expert and two novice residents, on improving the teaching paradigm during vertebroplasty. In this way, this limits the risks of complications during the skill acquisition phase that all learners must pass through. The complete simulation environment was evaluated on a 5-pt Likert scale format: (1) strongly disagree, (2) disagree, (3) neither agree nor disagree, (4) agree, and (5) strongly agree. When assessing all aspects of the realism of the simulation environment, specifically on whether it is suitable for the training of technical skills team training, the participating surgeons gave an average score of 4.5. Additionally, we also simulated a crisis simulation. During training, the simulation instructor introduced a visualisation depicting cement extravasation into a perivertebral vein. Furthermore, the physiology of the computerised mannequin was influenced by the instructor simulating a lung embolism by gradually lowering the oxygen saturation from 98% to 80% beginning at a standardised point during the procedure. The simulation was stopped after the communication between the surgeon and the anaesthetist occurred which determined their acknowledgment that an adverse event occurred. The realism of this crisis simulation was ranked with an average score of 4.75. To our knowledge this is the first virtual reality simulator with the capacity to control the introduction of adverse events or complication yielding a wide spectrum of highly adjustable crisis simulation scenarios. Our conclusions validate the importance of incorporating surgical workflow analysis together with virtual reality, human multisensory responses, and the inclusion of real
Introduction. Total Knee Replacement (TKR) is a highly effective treatment providing pain relief and improved function to patients experiencing advanced stage osteoarthritis. Tray fit or bone coverage is a critical design feature for both cemented and cementless designs affecting stability, load transfer and potential for infection. Many authors have attempted to characterise the relationship between the profile of the proximal tibia and gender and ethnicity. 1–3. As a consequence, a number of manufacturers have commercialised devices designed for specific gender and racial demographics. This study was initiated to compare the effect of the fixed minimum tibial resection depth prescribed by existing
INTRODUCTION. Rotational malalignment of the components in total knee arthroplasty has been linked to patellar maltracking, improper soft tissue balance, abnormal kinematics, premature wear of the polyethylene inlay, and subsequent clinical complications such as anterior knee pain (Barrack et al., 2001; Zihlmann et al., 2005; Lakstein at al., 2010). This study investigates an innovative image-based device that is designed to be used along with an intraoperative Isocentric (ISO-C) 3D imaging C-arm, and the conventional
Background. Currently existing optical navigation systems have ergonomic disadvantages such as size, the “line of sight” problem and extended registration procedures. The operation room becomes crowded by additional installations and competitive supporting devices around the patient. These points reduce and limit the acceptance of navigation systems for further applications. But especially for surgical quality management, navigation systems have a high potential as objective measurement systems. Method. A miniaturised measuring and navigation system, which is directly fixed at the surgical tool, could overcome these limitations and fulfil the requirements demanded by current and future operation rooms. Minimising the distance between situ and camera promises an increased accuracy, a reduced “line of sight problem,” intuitive handling and one coordinate transformation (Tool2DRB) less. However, such a setting reduces the navigation working space available, needs a sterile system, a new marker design and special requirements for the cameras. The developed prototypes were tested in vitro using Synbones™ and ex vivo at anatomical specimen. Following surgical pilot applications were defined and considered during the studies: maxillofacial restoration osteotomy, hip replacement and unicondylar knee replacements (UKR). Special emphasis was placed on measured and recorded accuracy and miniaturised hardware. Results. Several miniaturised measuring system prototypes with high resolution cameras mounted directly onto a