bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating the Feasibility of using Corn Ash and Wood Ash in Concrete in Florida
Authors: Sathe Ishan , Chini Abdol
Published: September 2020

The use of fly ash in concrete has seen a steady rise in the last few decades. Several government agencies in the US have specified a minimum quantity of fly ash as a substitute for Portland cement in concrete. In recent years, the generation of fly ash has reduced due to the decreasing reliance on using coal power plants and it is necessary to start looking at alternative options. Wood ash and corn ash have been considered as potential replacements to fly ash in concrete in countries like Nigeria and India. US is the largest producer of corn with majority of the production in the Midwest. Similarly, plenty of wood waste is available in Florida with almost 2.7 million metric tons being landfilled annually. This study used the literature data on properties of corn ash and wood ash and the test results on their use in concrete to demonstrate the feasibility of using them as a substitute for fly ash in production of low strength concrete in Florida. The environmental impacts of using fly ash along with corn ash and wood ash were also calculated and compared.
Strategies to Increase Adoption Rate of Lean Construction
Authors: Gao Zhili , Aslam Mughees , Smith Gary
Published: September 2020

Despite its enormous potentials for increasing efficiencies of the construction process, lean Construction (LC) has not been adopted into the majority of the construction industry yet. Furthermore, barriers and strategies for implementing LC have not been adequately studied by past and current research that can lead to the rapid uptake of LC within the construction industry. This study is to identify barriers that are hindering the construction industry to adopt LC and to further recommend suitable measures to overcome these barriers. In this study, a systematic literature review was carried out by reviewing theoretical/analytic papers, case studies and conceptual papers on the subject. After careful examination, eighty-seven (87) papers are kept for further analysis. Analysis indicated that approximately 80% of existing research studies are focused on identifying the implementation barriers only, whereas only 20%, presented barriers that hinder the adoption of LC. As a result, fifty-eight (58) barriers towards adopting LC and sixty-nine (69) strategies to overcome them were identified and classified under three population groups within the construction industry, based on their familiarity and implementation level of LC. The outcome of this study will potentially assist the construction industry in taking measures for increasing awareness and boosting the adoption rate of LC, along with the successful implementation of this innovative change management philosophy that ultimately will lead to optimized construction solutions.
Kinematic Analysis of Total Knee Arthroplasty(TKA) using Orthosensor system: Externally rotated femoral prosthesis versus Traditional design prosthesis
Authors: Na Seung-Min , Kim Gun-Woo , Lee Nam-Hun , Chung Young-Woo , Seon Jongkeun , Song Eun-Kyoo
Published: September 2020

Purpose The purpose of this study was to elucidate kinematic change according to the implant’s specific femoral rotation by using orthosensor implant with three degrees external rotation of femoral rotation rebuilt and traditional TKA implant without rebuilt of the femoral rotation .

Methods Twenty-eight patients (34 knees) underwent TKA using traditional TKA implant and 16 patients (22 knees) underwent TKA using implant with three degrees external rotation of femoral rotation. Patients were followed up for at least 1 year. Mean age of patients was 71.1 years (range, 60 to 80 years) at the time of surgery. After implantation of femur and tibial components, we applied the orthosensor system, to evaluate femoral rollback of the new artificial joint. Femoral rollback was analyzed using digitized screenshot function of orthosensor system.

Results Overall femoral tracking proportion regardless of implants was significantly higher on the medial compartment compared to that on the lateral compartment (13.3 ± 8.4% vs. 6.3 ± 5.0%, p < 0.001). Regarding femoral tracking according to each compartment, externally rotated femoral prosthesis and traditional prosthesis showed 12.1 ± 8.2% and 14.2 ± 8.6% (p = 0.371) on the medial compartment and 8.0 ± 5.8% and 5.2 ± 4.2% (p = 0.059) on the lateral compartment, respectively.

Conclusion Our study showed reverse femoral roll-back movement with higher tracking distance on the lateral compartment during TKA. externally rotated femoral prosthesis TKA system with femoral component 3-degree rebuilt showed less roll-back difference between medial and lateral compartments compared to traditional TKA system. Fortunately, both TKA systems had excellent short-term clinical outcomes without having significant difference between the two. With longer follow-up and larger cohort, the advantage and effectiveness of femoral component rotation can be elucidated in the future.
Clinical Evaluation of Artificial Intelligence based Preoperative Plans for Total Knee Arthroplasty
Authors: Lambrechts Adriaan , Ganapathi Muthu , Wirix-Speetjens Roel
Published: September 2020

A preoperative plan is a virtual plan that defines the implant position and orientation allowing a surgeon to prepare for surgery. However, the default preoperative plan for total knee arthroplasty proposed by the manufacturer requires changes to be made by the surgeon in more than 90% of the cases. Previous studies have shown that artificial intelligence can be used to create better preoperative plans compared to manufacturer’s default plans. However, the quality of artificial intelligence based preoperative plans has not yet been compared to surgeon approved preoperative plans. The purpose of this study is to compare default, artificial intelligence and surgeon approved preoperative plans, by having them scored on a range from 1 (totally unacceptable plan) to 5 (no corrections needed) by an experienced surgeon, while being blinded to the plan type. Through a Wilcoxon signed rank test with α=0.05, AI based preoperative plans were found to be a significant improvement upon the default plans (p-val=0.000136), while the differences in score between AI and surgeon approved preoperative plans were insignificant (p-val= 0.083). Consequently these results indicate that AI generated preoperative plans for TKA are an improvement upon current default plans, which could increase the surgeon’s planning efficiency when applied in clinical practice.
A Detailed analysis of Time taken in Robotic Surgery for Total Hip Replacement Arthroplasty and comparison with computer assisted navigation in Total Hip Replacement Arthroplasty
Authors: Deep Kamal
Published: September 2020

The accuracy of implantation using navigation and robotic hip replacement (THR) has been proven and accepted. Time taken for the use of technology, has been one of the major factors quoted by many surgeons for not using it. Aim was to analyse the time taken during different steps of the procedure and identify which part needs further improvement. Secondary aim was to compare the time with computer navigation technology. 20 total joint replacements were carried out with MAKO robotic system using extended software version, which includes both acetabular and femoral guidance. The times of different surgical steps were noted. After the incision was made, and joint exposed the trackers for the pelvis and femur were then inserted, tightened and verification pins inserted. Femoral registration matching was started at 15 minutes (SD5.4 Range7-22). Femoral Neck Cut level was made at 22.5 minutes (SD4.5 Range15-29). It took mean 7.5 minutes to match the femoral anatomy to preop CT scan anatomy. Pelvic registration matching was done at 42.4 minutes (SD5.9 Range33-50). It took average 8.4 minutes to match pelvic anatomy. Bone reaming was with robotic arm at 50.8minutes (SD5.5 Range40-57). The cup was impacted at 56.2 minutes (SD5.2 Range45-60). Cementing stem added 14 minutes. The navigation hip replacement surgery took mean 60 minutes in uncemented and 72minutes for cemented stems. Robotic technique took 10 minutes longer. There is room for improvement in two main modifiable steps. Total registration matching time which took 16 minutes and using a uncemented stem. Should time constraint supersede accuracy achievable with technology?
ARCH-COMP20 Category Report:Hybrid Systems Theorem Proving
Authors: Mitsch Stefan , Huerta Y Munive Jonathan Julián , Jin Xiangyu , Zhan Bohua , Wang Shuling , Zhan Naijun
Published: September 2020

This paper reports on the Hybrid Systems Theorem Proving (HSTP) category in the ARCH-COMP Friendly Competition 2020. The characteristic features of the HSTP category remain as in the previous editions [MST+18, MST+19]: i) The flexibility of pro- gramming languages as structuring principles for hybrid systems, ii) The unambiguity and precision of program semantics, and iii) The mathematical rigor of logical reason- ing principles. The HSTP category especially features many nonlinear and parametric continuous and hybrid systems. Owing to the nature of theorem proving, HSTP again accommodates three modes: A) Automatic in which the entire verification is performed fully automatically without any additional input beyond the original hybrid system and its safety specification. H) Hints in which select proof hints are provided as part of the input problem specification, allowing users to communicate specific advice about the sys- tem such as loop invariants. S) Scripted in which a significant part of the verification is done with dedicated proof scripts or problem-specific proof tactics. This threefold split makes it possible to better identify the sources of scalability and efficiency bottlenecks in hybrid systems theorem proving. The existence of all three categories also makes it easier for new tools with a different focus to participate in the competition, wherever they focus on in the spectrum from fast proof checking all the way to full automation. The types of benchmarks considered and experimental findings with the participating theorem provers KeYmaera, KeYmaera X 4.6.3, KeYmaera X 4.8.0, Isabelle/HOL/Hybrid-Systems-VCs, and HHL Prover are described in this paper as well.
ARCH-COMP20 Category Report: Hybrid Systems with Piecewise Constant Dynamics and Bounded Model Checking
Authors: Bu Lei , Abate Alessandro , Adzkiya Dieky , Syifa'Ul Mufid Muhammad , Ray Rajarshi , Wu Yuming , Zaffanella Enea
Published: September 2020

This report presents the results of a friendly competition for formal verification of continuous and hybrid systems with piecewise constant dynamics. The friendly competition took place as part of the workshop Applied Verification for Continuous and Hybrid Systems (ARCH) in 2020. In this fourth edition, five tools have been applied to solve six different benchmark problems in the category for piecewise constant dynamics: BACH, PHAVerLite, PHAVer/SX, TROPICAL, and XSpeed. Compared to last year, we combine the HBMC and HPWC categories of ARCH-COMP 2019 to a new category PCDB (hybrid systems with Piecewise Constant bounds on the Dynamics (HPCD) and Bounded model checking (BMC) of HPCD systems). The result is a snapshot of the current landscape of tools and the types of benchmarks they are particularly suited for. Due to the diversity of problems, we are not ranking tools, yet the presented results probably provide the most complete assessment of tools for the safety verification of continuous and hybrid systems with piecewise constant dynamics up to this date.
High Offset Stems are Protective of Dislocation in High Risk Total Hip Arthroplasty
Authors: Vigdorchik Jonathan , Sharma Abhinav , Elbuluk Ameer , Carroll Kaitlin , Mayman David , Lieberman Jay
Published: September 2020

Background: Spinal stiffness has been shown to increase risk of dislocation due to impingement and instability. Increasing anteversion of the acetabular component has been suggested to prevent dislocation, but little has been discussed in terms of femoral or global offset restoration. The purpose of this study is to quantify dislocation rates after primary THA using standard versus high offset femoral components and to determine how differences in offset affect impingement-free range of motion in a stiff spine cohort using a novel impingement model. Methods: 12,365 patients undergoing THA from 2016-2018 were retrospectively reviewed to determine dislocation rates and utilization of standard versus high offset stems. For 50 consecutive patients with spinal stiffness, a CT-based computer software impingement modeling system assessed bony or prosthetic impingement during simulated range of motion. The model was run 5 times for each patient with varying offsets. Range of motion was simulated in each scenario to determine the degree at which impingement occurred. Results: There were 51 dislocations for a 0.41% dislocation rate. Total utilization of high offset stems in the entire cohort was 49%. Of those patients who sustained a dislocation, 49 (96%) utilized a standard offset stem. The impingement modeling demonstrated 5 degrees of added range of motion until impingement for every 1mm offset increase. Conclusion: In the impingement model, high offset stems facilitated greater ROM before bony impingement and resulted in lower dislocation rates. In the setting of high-risk THA due to spinal stiffness, surgeons should consider the use of high-offset stems and pay attention to offset restoration.
Comparison of Construction Scheduling Perspectives from General Contractors and Sub-Contractors: An Analysis of Current Tools and Practices
Authors: Bingham Evan , Farnsworth Clifton , Smith James
Published: September 2020

Construction project managers are continually seeking to balance the limited resources of time and money. To do this, collaborative management is critical. Most importantly, communication is the key to collaborative management. One of the most important forms of communication is the creation of a project schedule. Information on the tools and practices used by industry can help improve these practices for managers. Likewise, decision makers in the industry should understand trends to see if they align with peers, or to find justification for differences. The objectives of this study are to determine the tools used to create a project schedule, who is creating the schedule, and how often the schedule is communicated. The study is a comparison of views from the perspectives of the general contractors and that of the subcontractors. Additionally, the study examines the perceptions of general and subcontractors to determine the causes of schedule delays. This study is a report of commercial contractors performing work in the United States that provides information on the tools and practices currently used in construction scheduling. This study is valuable for industry leaders and academics seeking information about scheduling tools, practices and perceptions that can be implemented into a company scheduling culture or used for instructional purposes.
Disaster Preparedness Education: Construction Curriculum Requirements to Increase Students’ Preparedness in Pre- and Post-Disaster Activities
Authors: Nipa Thahomina Jahan , Kermanshachi Sharareh , Patel Ronik , Tafazzoli Mohammadsoroush
Published: September 2020

Students are one of the vulnerable groups of people affected by a disaster, as they suffer both physically and mentally. Concerns are rising, as educational institutions lack adequate emergency programs to prepare students for disasters. Moreover, the integration of disaster preparedness in the coursework is rarely done for students with majors such as construction. This study performs a comprehensive literature review to integrate the research related to students’ disaster preparedness and provide strategies to increase students’ disaster preparedness. To fulfill this aim, 83 of the most recent scholarly articles were collected and scrutinized. The current trends in disaster preparedness curriculums in construction programs, as well as other majors, were studied, strategies for enhancing these programs espoused by researchers were investigated, and challenges/barriers to providing disaster preparedness education were analyzed. It was concluded that the integration of hands-on practices of rescue activities into construction curriculums, along with theoretical knowledge of disasters, significantly helps students to be prepared for a disaster and for post-disaster mitigation efforts hence should be included in the disaster preparedness curriculum. Lack of resources and trained personnel is one of the major causes of insufficient integration of disaster preparedness materials in the course curriculum. This study will assist in updating the existing programs, enhancing construction students’ disaster preparedness, addressing potential challenges to the advancement of knowledge, and reducing damages.
Robotic vs Navigational vs Conventional Primary Total Knee Arthroplasty. Clinical and Radiological Long-Term Results with a Minimum Follow-up of 10 years -Survivalship Analysis-
Authors: Na Seung-Min , Kim Gun-Woo , Nam-Hun Lee , Chung Young-Woo , Seon Jongkeun , Song Eun-Kyoo
Published: September 2020

The aim of this study was (1) to compare the clinical and radiological outcomes of robotic, navigational and conventional total knee arthroplasty with a minimum follow-up of 10 years, (2) to evaluate the survival rate, (3) and to estimate the accuracy of the three techniques by analyzing the outliers of the total knee arthroplasty (TKA) patients.

Methods From January 1992 to December 2008, We evaluated 515 knees who underwent robotic TKA, navigational TKA, or conventional TKA with minimum follow-up of 10 years. Finally, this study including 92 patients (103 knees) who underwent robotic total knee arthroplasty using ROBODOC® , 197 patients (225 knees) who underwent navigational total knee arthroplasty using Orthopilot, and 175 patients (187 knees) who underwent conventional total knee arthroplasty. Hospital for special surgery(HSS) score, Knee Society Score(KSS), Western Ontario and McMaster Universities (WOMAC), and Range of Motion(ROM) were used for clinical evaluation. Mechanical alignment, implant radiological measurements and outliers were analyzed for radiological results. Complication related with surgery was also evaluated. Data were analyzed using SPSS Version 24.0 software and descriptive statistics, paired t‑test, one‑way ANOVA, and Wilcoxon tests. Kaplan-Meier survival analysis was performed for survival rate.

Results All clinical assessments including HSS, KSS, WOMAC, and ROM at final follow-up showed excellent improvements in three groups (all, p<0.05), without any significant difference between the groups (p>0.05). In radiologic data, sagittal inclination of femoral implant in robotic group showed better result than another groups with significant difference(p<0.05). The cumulative survival rate was 94.8% in the robotic group, 96.2% in the navigation group, and 92.4% in the conventional TKA group with excellent survival (p=0.563). Complication rate associated surgery was 5.2 % in the robotic group, 5.3% in the navigation group, and 8% in the conventional group

Conclusion Our study showed excellent survival with robotic, navigation and conventional TKA and similar clinical outcomes at long-term follow-up. However, in terms of radiological outcome robotic TKA showed accurate position of femoral component. With longer follow-up and larger cohort, the accuracy and effectiveness of robotic TKA on implant survival rate can be elucidated in the future.
Exploratory Study of MBAs With Technical Specializations in Construction and Project Management
Authors: Attallah Sherif , Jones James , Simpson Mathew
Published: September 2020

There is an absence of data in the available literature on the current status of programs that offer an MBA with a technical specialization. This study addresses that absence of data with an overall discussion of MBA specializations and an investigation of MBAs that offer a technical specialization in construction management (CM) and project management (PM). Information on programs that offer CM or PM technical specializations was collected using a university’s official website, as well as, phone conversations with personnel. A total of 39 of 368 MBA programs offered the CM and/or PM technical specialization. These programs were analyzed across multiple data points such as cost, courses, and time to completion. Data collected on the availability of MBAs with a technical specialization in either CM or PM revealed that both curriculums are virtually nonexistent across academia. Universities that begin to offer PM or CM technical specializations will be filling a current knowledge gap that will benefit both students and employers alike. Further research into the degree that employers prefer technical specialization is needed. The data collected in this study indicate that there are still areas of study that MBA programs can address with the introduction of new technical specializations.
Relative Trends Associated with the International Journal of Construction Education and Research
Authors: Farnsworth Clifton , Bingham Evan , Smith James
Published: September 2020

The International Journal of Construction Education and Research (IJCER) is an academic peer- reviewed journal supported by the Associated Schools of Construction, publishing scholarly work associated with construction education and research. One challenge the IJCER has faced since its inception is establishing itself as a high quality, scholarly impactful publication. The purpose of this paper is to explore the relative trends associated with the IJCER, including the current state of academic impact metrics, a relative comparison of papers published by author and institution, and international and collaborative efforts. The results of this research indicated that the IJCER continues to improve its academic stature through increasing impact metrics. Since the inception of the IJCER in 2004, a total of 479 unique authors, representing 158 different institutions have been associated with IJCER papers. International and collaborative efforts have also been strongly represented and continue to be one of the strengths of the journal. This information can be used to help identify similar publishing peer groups and justify relative scholarly impact for those who publish in the IJCER. This research also identifies the breadth of impact the Associated Schools of Construction is providing its membership by sponsoring an academic peer reviewed journal.
A Framework for Life Cycle Assessment and Cost Analysis of Precast and Cast-in-Place Buildings in United States
Authors: Vasishta Tanmay , Mehany Mohammed
Published: September 2020

The concept of construction sustainability has been gaining traction over years now. A large number of tools has been used to assess economic and environmental impacts of the buildings. LCA and LCCA are one of the most widely used tools to evaluate the environmental and economic impacts of the buildings over their complete life cycle. The aim of this research is to develop a framework for assessing the economic and environmental impacts of precast and cast-in-place buildings constructed in United States through Open LCA software. The study will include unit processes and material flows from raw material extraction and manufacturing phase to demolition phase of a building (cradle-to-grave) over the life span of 50 years. The developed framework for LCA and LCCA could be applied to all concrete construction projects across the world and could be used as platform for conducting future LCA and LCCA studies as well. Future research could be conducted through probabilistic approach of calculating the annual cost impacts over the complete life cycle of a building.
Evaluating Optimization Solvers and Robust Semantics for Simulation-Based Falsification
Authors: Lidén Eddeland Johan , Miremadi Sajed , Åkesson Knut
Published: September 2020

Temporal-logic based falsification of Cyber-Physical Systems is a testing technique used to verify certain behaviours in simulation models, however the problem statement typically requires some model-specific tuning of parameters to achieve optimal results. In this experience report, we investigate how different optimization solvers and objective functions affect the falsification outcome for a benchmark set of models and specifications. With data from the four different solvers and three different objective functions for the falsification problem, we see that choice of solver and objective function depends both on the model and the specification that are to be falsified. We also note that using a robust semantics of Signal Temporal Logic typically increases falsification performance compared to using Boolean semantics.
Development of individual medical implants with specific mechanical properties manufactured by Laser Powder Bed Fusion
Authors: Willkomm Johannes , Jauer Lucas , Ziegler Stephan , Schleifenbaum Johannes Henrich
Published: September 2020

Laser Powder Bed Fusion (LPBF) is an additive manufacturing process, which enables the generation of complex geometries such as lattice structures, using metallic powder. Lattice structures are being used increasingly in medical technology to adapt the stiffness of individualized implants which can lead to faster bone healing. Lattice structures are also used to adjust the contact surface between the bone and implant to adapt the osseointegrative behavior. The goal of this work is to create lattice structures with local adaption of the stiffness (modulus of elasticity) for individual vertebral body replacement implants and their automated design based on patient data.

To form the lattice structure a diamond cell type is used, which is common in medical technology. For the later adaptation of the bone stiffness, the stiffness of the lattice structure with different strut diameters are determined. The calculation of the stiffness is done by numerical simulations using Finite Element Methods (FEM). The simulations are validated with tensile and compression tests. Finally, the automated design of the implants is carried out with an in-house generated tool to adjust the strut diameters based on the bone density from patient data.

Parts of this work have been funded by the German ministry of education and research (BMBF) under grant number 13GW0116.
Functional Correctability of the Knee Joint using 3D-to-2D Registration of X-Ray Imaging in Stressed Positions
Authors: Li Jialong , Liu David , McMahon Stephen , Baré Jonathan , Shimmin Andrew , Miles Brad , Li Qing , Twiggs Joshua
Published: September 2020

Correcting the knee joint to accommodate the pre-existing soft tissue structures is a major aim in total knee arthroplasty. 3D-to-2D registration of segmented boney geometry obtained from computer tomography (CT) scans to functionally stressed positions in X-Ray (XR) imaging can be a more accurate method of obtaining the laxity envelop. From which, a more patient specific limit for the correctability of the knee joint can be found. Supine CT scans were segmented, and 3D bone models and anatomical landmarks were registered to 2D functional stressed XR imaging. The functional position of the patient femoral and tibial bone is then used to calculate the varus and valgus extent of the patient’s knee joint laxity. 103 preoperative knees undergoing primary total knee arthroplasty identified from six different surgeons. The range of patients who are correctable back to within 3 degrees when a force is applied is 52%. 65% of patients who were within 3 degrees varus/valgus for tibia varus were correctable, while 41% of patients who were within 3 degrees varus/valgus for femoral valgus were correctable. 26% of patients were correctable when the LDFA is outside the threshold and MPTA is not, while 56% of patients were correctable when the MPTA is outside the threshold and LDFA is not. This study demonstrates the complexity of soft tissue structures of the knee joint. The main finding of this study is that correctability is more sensitive to the proximal tibial than the distal and posterior femoral articulating geometry. A lack of dependency between correctability of the knee joint and anatomical measures specific to flexion of the knee is seen. Careful consideration should be made intraoperatively when balancing the knee joint flexion gaps surrounding the soft tissue structures.
The public perception of prefabricated housing in the UK
Authors: Shah Raj , O'Mahony Leigh , Matipa Wilfred , Cotgrave Alison
Published: September 2020

The UK has been in a housing crisis for many years and it has missed its house building targets by over 1.3 million houses since 2004. Something needs to change to achieve government target. Prefabricated homes could be a solution to this issue since they could bring overall construction duration down, keep the costs lower and provide higher quality homes as they are produced in a controlled factory environment rather than on site and open to other elements. However, many controlling factors such as higher initial investment, incomplete industry supply chain and public perception have had a major impact on their limited usage up to this point. The aim of this paper is to examine the public perception regarding the prefabricated housing in the UK using a mixed research methodology with the questionnaire survey. There has been limited research in this area and the majority of research has focused on the technology involved and the sustainability impact of prefabricated housing. The survey results reveal that the UK public can struggle to accept a prefabricated house due to the lack of information regarding prefabricated housing. A common belief is that the UK government needs to support this type of housing with a financing package to encourage them to buy the prefabrication houses and builders need to inject more houses in market.
Virtual pre-operative planning in acetabular surgery using a patient-specific biomechanical model: a prospective clinical study.
Authors: Boudissa Mehdi , Chabanas Matthieu , Bahl Gaetan , Oliveri Hadrien , Tonetti Jérôme
Published: September 2020

The first patient-specific biomechanical model for pre-operative planning in acetabular surgery was developed in our institution and validated in previous retrospective studies. The aim of this prospective clinical study was to confirm the previous promising.

Between January 2019 and June 2019, every patients operated by the first author for acetabular fracture were included in this prospective study. A biomechanical model was implemented in acustom software made from combination of several open-sources software allowing a biomechanical simulation. The surgery was then performed according to the simulation. Surgery duration, blood loss, radiological results and per- operative complications were recorded.

Ten patients were included. Mean simulation time was 22 min ± 4 [range, 18-31]. The mean operative time was 113 min ± 33 [range, 60-180] and mean blood loss was 505 mL ± 189 [range, 100-750]. On Matta’s criteria, anatomic reduction was achieved in 9 of the 10 patients (90%; 0.8 mm ± 1 [range, 0-3]). No per-operative complications were recorded.

This study confirms the promising results of pre-operative planning in acetabular surgery based on a patient-specific biomechanical model.The model needs larger-scale prospective validation, but offers a new tool suitable for teaching purposes and for assessment of surgical strategies in acetabular fracture.
Architecture for Augmented Reality Guidance Applications Using DICOM-RTV
Authors: Guinin Maxime , Pasquier Guillaume , El Jaouhari Saad , Hardy Patrick , Waechter Julien , Bridault Flavien , Hostettler Alexandre , Marescaux Jacques
Published: September 2020

The recently published DICOM-Real Time Video (DICOM-RTV) standard allows real-time synchronization of transported video and medical metadata flows. In order to demonstrate the advantages of this synchronization by design, a demonstration of a DICOM-RTV Augmented Reality (AR) based solution is proposed. This solution consists in facilitating the surgeon's gesture by monitoring the positioning of the biopsy needle under ultrasound guidance and constructing virtual and augmented reality views of the needle's trajectory. In this paper, the platform architecture and the obtained results are presented. Furthermore, a comparison between our proposed solution and a setup that do not use DICOM-RTV is provided in order to show the difference in term of precision, synchronization and delay. The obtained results validate the contribution of real-time synchronization to improve the accuracy of surgical gesture aid applications such as AR.
Using Primary Implants for Revision Total Knee Arthroplasty Thanks to Navigated Intra-Operative Analysis.
Authors: Jenny Jean-Yves , Ginot Geoffrey
Published: September 2020

Using navigated analysis of bone and ligamentous status during revision total knee arthroplasty allows using frequently primary implants instead of revision ones.
Automatic muscle elongation measurement during shoulder arthroplasty planning
Authors: Pitocchi Jonathan , Plessers Katrien , Wesseling Mariska , van Lenthe G. Harry , Pérez Maria Angeles
Published: September 2020

Adequate deltoid and rotator cuff lengthening in total shoulder arthroplasty (TSA) is crucial to maximize the postoperative functional outcome and to avoid complications. Hence surgeons and patients could benefit from including muscle length information in preoperative planning software.

Although different methods have been introduced to automatically indicate patient-specific muscle attachment and wrapping points, the definition of a fast and accurate workflow is still a challenge, due to the large variability in bone shapes. Therefore, the goal of this study is to develop and evaluate the accuracy of a novel method to automatically estimate muscle elongation, based on a statistical shape modelling (SSM) approach.

Firstly, humerus and scapula SSMs were used to automatically indicate the attachment points of the main shoulder muscles: subscapularis, supraspinatus, infraspinatus, teres minor and deltoid. Secondly, a wrapping algorithm was applied to identify the points where muscles wrap around bones or potential implants. Finally, the accuracy of the automatically indicated landmarks and its effect on the muscle elongation were evaluated by comparing the manually indicated landmarks with the landmarks identified through the SSM for a set of 40 healthy shoulder CT-scans.

The low errors on elongation values suggest that the presented automated workflow is a promising tool for allowing surgeons to evaluate patient-specific muscle elongations during preoperative planning. Although the evaluation was limited to healthy joints, this method allows to easily process large datasets and to potentially find a correlation between muscle elongations and postoperative outcome.
Evaluating the Use of Unmanned Aerial Systems (UAS) to Perform Low-Slope Roof Inspections
Authors: Gajjar Dr. Dhaval , Burgett Dr. Joseph
Published: September 2020

The use of Unmanned Aircraft Systems (UAS) or Drones are being explored for a wide range of civilian applications. The Federal Highway Administration (FHWA) recently reported that “construction inspectors that use UAS are reducing inspection time, improving effectiveness, increasing safety, and lowering costs.” If the FHWA is enjoying these benefits by leveraging this technology, it stands to reason that other industries that perform similar functions would also benefit. This study explores the opportunity of using commercially available UAS and structure-from-motion software to replace an in-person inspection for a low slope roof. The goal of the study was to see how much of a traditional in-person roof inspection could be replaced with a 3D photogrammetric model created from drone imagery. In this experiment, a SME roofing inspector identified deficiencies exclusively from a 3D model. Then, the SME inspected the low-slope roof in-person using traditional practices. The SME identified 191 specific deficiencies using 3D model and 200 deficiencies from the traditional method. The defects easiest to identify were open laps, alligatoring, punctures, wrinkles on the roof membrane and damages around the edges whereas total number and square feet of blisters, damages around penetration were the most difficult to identify in the model.
Active Learning Techniques in Understanding Risk Associated with Planning
Authors: Templin Lee , Miller Richard
Published: September 2020

In the construction industry, projects involve a variety of techniques to communicate the project plan and the many parts associated with successful completion. While all are important elements of the project, the construction plan is a vital part of the project’s success and how it is created, used, revised, and evaluated. Educators use various delivery methods in the classroom to teach planning and scheduling but the many intangibles out of the control of the scheduler make it difficult to convey all the concepts associated with these key elements of the project. Using active learning methods, such as a board game, engages the learner, introduces intangibles and promotes critical thinking and problem-solving skills for the CM student. Results from the study will provide insight into active learning and the possibilities of developing learning tools that can assist young professionals in the field. This element of instruction is paramount to the success of the new transitional student in programs across the country. Passive learning experiences no longer mimic the active projects that are prevalent in the industry today. Using the results from this study will illuminate opportunities in the classroom using active learning as a vehicle for synthesizing knowledge.
Passive ligament stability in natural knee: a cadaveric biomechanical study
Authors: Paszicsnyek Thomas , Bori Edoardo , Innocenti Bernardo
Published: September 2020

Objectives: Applying the correct amount of collateral ligaments tension in the knees during surgery is a prerequisite to restore normal kinematics after TKA. It is well known that a low value of ligament tension could lead to an instable joint while a higher tension could induce over-tensioning and problems at later follow-up. In this study, an experimental cadaveric activity was performed to measure the minimum tension required to achieve stability in the knee joint.

Methods: 10 cadaveric knee specimens were investigated in this study. The femur and tibia were fixed with polyurethane foam in specific designed fixtures and clamped to a loading frame.

Increasing displacement was applied to the femoral clamp and the relative force was measured by a loading-frame machine up to the stability of the joint, determined by a decrease in the derivate of the force/displacement trend followed by a plateau.

The force span between the slack region and the plateau was considered as the tension required to stabilize the joint.

This methodology was applied for joints with intact cruciate ligaments, after ACL resection and after further PCL resection, to simulate the knee behavior prior a CR and a PS implant.

The test was performed at 0, 30, 60 and 90° of flexion. Each configuration was analyzed three times for the sake of repeatability.

Results and Conclusion: Results demonstrated that an overall tension of 41.2N (range 30.0-48.0 N) is sufficient to reach stability in a native knee with intact cruciate ligaments. Similar values appear to be sufficient also in an ACL resected knee (average 45.6, range 41.2-50.0 N), while higher tension is required (average 58.6N, range 40.0-77.0 N) were necessary in the case of PCL retention. Moreover, in this configuration, the tension required for stabilization was slighter higher at 30 and 60° of flexion compared to the one required at 0 and 90° of flexion.

The results are in agreement to the ones found by other recent experimental study [Manning et al 2018 (KSSTA)] and shown that the tension necessary to stabilize a knee joint in different ligament conditions is way lower than the ones usually applied via tensioners nowadays.

To reach functional stability, surgeons need to consider such results intraoperatively to avoid laxity, mid-flexion instability or ligament over-tension.
Initial Student Perception of the Benefits of Participation on an International ASC Competition Team
Authors: Wentz Blake , Yates Heather , Das Majumder Sreemala
Published: September 2020

The construction industry is becoming more diverse and global in terms of the project workforce. There is a significant need for universities to provide educational opportunities for students in order to prepare them to operate in a global market. Currently, there are limited opportunities to gain an international experience in construction management programs in the U.S., with most being limited to a study abroad program. But the advent of the International ASC Student Competitions has opened new opportunities for students to engage in a collaborative team and gain exposure to internationalization in construction. This paper surveyed students from two such teams to determine their perceptions of the experience, with all students indicating the benefits far outweigh the challenges of being on such a team. These initial perceptions point to further study the significance of these international competition teams in terms of increasing student experiences abroad.
The Incidence of Soft-Tissue Releases in Robotic-Assisted Total Knee Arthroplasty Technology
Authors: Kaper Bertrand
Published: September 2020

The incidence of formal soft tissues releases required in TKA surgery performed utilizing the NAVIO robotic-assisted (RA)-TKA technique was assessed and compared to a historical cohort of conventional, manually instrumented (CI) TKA’s.
Standard Cruciate-Retaining Total Knee Arthroplasy Implants Can Reproduce Native Kinematics
Authors: Dejtiar David Leandro , Bartsoen Laura , Wesseling Mariska , Wirix-Speetjens Roel , Vander Sloten Jos , Perez Maria Angeles
Published: September 2020

Total knee arthroplasty (TKA) is a common procedure that has become the standard of treatment for severe cases of knee osteoarthritis. Biomechanics and quality of movement similar to healthy were found to improve patient-reported outcomes.

In this study, an evaluated musculoskeletal model predicted ligament, contact and muscle forces together with secondary tibiofemoral kinematics. An artificial neural network applied to the musculoskeletal model searched for the optimal implant position in a given range that will minimize the root-mean-square-error (RMSE) between post- TKA and native experimental tibiofemoral kinematics during a squat.

We found that, using a cruciate-retaining implant, native kinematics could be accurately reproduced (average RMSE 1.47 mm (± 0.89 mm) for translations and 2.89° (± 2.83°) for rotations between native and optimal TKA alignment). The required implant positions changes maximally 2.96 mm and 2.40o. This suggests that when using pre- operative planning, off-the-shelf CR implants allow for reproducing native knee kinematics post-operatively.
A Novel Computer-Assisted Workflow for Treatment of Osteochondral Lesions in the Knee
Authors: Tatti Fabio , Iqbal Hisham , Jaramaz Branislav , Rodriguez Y Baena Ferdinando
Published: September 2020

Computer-Assisted Orthopaedic Surgery (CAOS) is now becoming more prevalent, especially in knee arthroplasty. CAOS systems have the potential to improve the accuracy and repeatability of surgical procedures by means of digital preoperative planning and intraoperative tracking of the patient and surgical instruments.

One area where the accuracy and repeatability of computer-assisted interventions could prove especially beneficial is the treatment of osteochondral defects (OCD). OCDs represent a common problem in the patient population, and are often a cause of pain and discomfort. The use of synthetic implants is a valid option for patients who cannot be treated with regenerative methods, but the outcome can be negatively impacted by incorrect positioning of the implant and lack of congruency with the surrounding anatomy.

In this paper, we present a novel computer-assisted surgical workflow for the treatment of osteochondral defects. The software we developed automatically selects the implant that most closely matches the patient’s anatomy and computes the best pose. By combining this software with the existing capabilities of the Navio™ surgical system (Smith & Nephew inc.), we were able to create a complete workflow that incorporates both surgical planning and assisted bone preparation.

Our preliminary testing on plastic bone models was successful and demonstrated that the workflow can be used to select and position an appropriate implant for a given defect.
Predictive Ligament Balancing in Robotic TKA – One Year Clinical Outcomes from a Multicenter Study
Authors: Keggi John , Lawrence Jeffrey , Randall Amber , DeClaire Jeffrey , Ponder Corey , Koenig Jan , Shalhoub Sami , Wakelin Edgar , Plaskos Christopher
Published: September 2020

This study reports on the one-year clinical results and patient reported outcomes (PROMs) associated with a new ‘predictive balance’ tibia-cut first total knee arthroplasty (TKA) technique that uses a robotic ligament tensioner. PROMs are compared to registry data and historical results in the literature.

Five hundred and thirty-three patients were prospectively enrolled and underwent robotic TKA (mean age: 67.7±8.4; females: 320; BMI: 31.2±4.9). Pre-op, three, six and 12-month WOMAC, UCLA activity scale, and HSS-Patient satisfaction assessments were completed by 533, 352, 314, and 256 patients, respectively, and compared to WOMAC registry data from the Shared Ortech Aggregated Repository (SOAR) and to historical satisfaction reports in the literature.

Despite having equivalent baseline PROM scores, predictive balance patients had significantly higher WOMAC scores at all post-operative timepoints (p<0.001) and higher UCLA activity scale scores at 3M and 6M (p<0.013). Overall patient satisfaction in the predictive balance cohort was 91.2%, 92.4%, and 96.5% at 3M, 6M and 1YR, respectively. Average length of stay was 1.6 days (±0.8). Surgical complications in this cohort were typical of TKA.

Limitations to this study include the lack of a closely matched control group. Nonetheless, first year results are promising with improved objective measures compared to large registry databases and recently reported patient satisfaction measures.