scholarly journals The Captain’s View: A Novel Radiographic View to Assess Axial Alignment of the Calcaneus

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0042
Author(s):  
Brian Velasco ◽  
Bruno Moura ◽  
John Kwon
Keyword(s):  
Soft Tissues ◽  
Articular Surface ◽  
Lateral Wall ◽  
Varus Deformity ◽  
High Rate ◽  
Clear Correlation ◽  
Lateral Side ◽  
Axial Alignment ◽  
Wide Range ◽  
Fresh Frozen

Category: Hindfoot, Trauma Introduction/Purpose: The axial alignment of the calcaneus has paramount importance in the management of these fractures. The Harris view has long stood as the recommended radiograph to assess axial alignment. However, given the obliquity at which the radiograph is obtained, it doesn´t represent a true axial view and is subject to inaccuracies secondary to rotational malpositioning of the foot and mismeasurement of angulation. Multiple reports have described the axial alignment as a surgical outcome, but usually this assessment of the residual deformity have no described method. The objectives of this study are to evaluate the capacity of Harris view to assess axial alignment in a cadaveric model and to describe the use of a true AP view of the calcaneus that we have named Captain´s view. Methods: Five below knee amputated fresh-frozen cadaveric specimens were used in the study. For each specimen, the soft tissues over the lateral side were removed to access to the lateral wall. A small wedge of the cuboid was removed to visualize the center of the calcaneocuboid articular surface. LCA-guide and a cannulated drill were used to create a tunnel in the axis of the calcaneus. An oblique osteotomy was performed in order to simulate a non-comminuted fracture. Varus deformity was created by inserting solid radiolucent wedges into the osteotomy to create models of 10, 20, and 30 degrees of varus angulation. Harris and Captain views were obtained for each specimen with 0 (control), 10, 20, and 30 degrees of varus malalignment. Measurements of the deformity were made digitally on each fluoroscopic image. Results: The average degrees of varus in Harris views were 10,9 (5,5-16); 11,5 (8,2-13,6); and 18,3 (13,3-23,6) for 10,20 and 30 degrees of deformity respectively. The average degrees of varus in Captain´s view were 13,0 (7,3-20,9); 18,4 (11,7-23,5); and 28,2 (24,4-31,1) for 10,20 and 30 degrees of deformity respectively. The average degrees of error for varus deformity in Harris views were 4,1 (41%); 8,4 (42%) and 11,6 (39%) for 10,20 and 30 degrees of deformity respectively. The average degrees of error for varus deformity in Captain´s views were 4,8 (48%); 3,6 (18%) and 2,8 (8%) for 10,20 and 30 degrees of deformity respectively. Conclusion: The results of this study show a high rate of mismeasurement for both radiographic views. Despite the average angles have a clear correlation with the severity of varus, the wide range of error observed between specimens make this assessment unreliable and inaccurate. We observed an improvement of accuracy of captain´s view for more severe deformities, but not with Harris views which maintain a 40% mismeasurement in all the settings. Therefore, intraoperative Harris views should not be used in isolation to evaluate axial alignment and Captain´s view provides an additional perspective that can be useful to rule out severe deformities.

Achilles Tendon Insertion: An In Vitro Anatomic Study

1997 ◽  
Vol 18 (2) ◽  
pp. 81-84 ◽  
Author(s):  
Wen Chao ◽  
Jonathan T. Deland ◽  
James E. Bates ◽  
Sharon M. Kenneally
Keyword(s):  
Achilles Tendon ◽  
Lateral Wall ◽  
Posterior Wall ◽  
Lateral Side ◽  
Achilles Tendinitis ◽  
Fresh Frozen ◽  
Significant Extension ◽  
Tendon Insertion ◽  
Inferior Border

Seventeen adult fresh-frozen below-knee amputation cadaver specimens were studied. Calcific Achilles tendinitis was present in three specimens. After exposing the Achilles tendon insertion on the calcaneus, the insertion was outlined with waterproof paint. The specimens were photographed on a special plexiglass apparatus to highlight important findings. For the purpose of showing the length of insertion on lateral radiographs, lead beads were placed on the most superior and most inferior aspects of the insertion. All specimens showed that the tendon terminated at the medial and lateral bone borders of the calcaneus without significant extension around the medial or lateral wall. All specimens revealed a greater distance of insertion on the medial calcaneus than on the lateral side. In the specimens that had calcific Achilles tendinitis, the posterior bone surface of the spurs was devoid of tendinous insertion. Instead, the insertion occurred between the spur and the posterior wall of the calcaneus. All spurs were located laterally at the most inferior border of the tendon insertion.

scholarly journals Quantification of assembly forces during creation of head-neck taper junction considering soft tissue bearing: a biomechanical study

Arthroplasty ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Toni Wendler ◽  
Torsten Prietzel ◽  
Robert Möbius ◽  
Jean-Pierre Fischer ◽  
Andreas Roth ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Work Experience ◽  
Soft Tissues ◽  
Force Sensor ◽  
Biomechanical Study ◽  
Measuring System ◽  
Wide Range ◽  
Head Neck

Abstract Background All current total hip arthroplasty (THA) systems are modular in design. Only during the operation femoral head and stem get connected by a Morse taper junction. The junction is realized by hammer blows from the surgeon. Decisive for the junction strength is the maximum force acting once in the direction of the neck axis, which is mainly influenced by the applied impulse and surrounding soft tissues. This leads to large differences in assembly forces between the surgeries. This study aimed to quantify the assembly forces of different surgeons under influence of surrounding soft tissue. Methods First, a measuring system, consisting of a prosthesis and a hammer, was developed. Both components are equipped with a piezoelectric force sensor. Initially, in situ experiments on human cadavers were carried out using this system in order to determine the actual assembly forces and to characterize the influence of human soft tissues. Afterwards, an in vitro model in the form of an artificial femur (Sawbones Europe AB, Malmo, Sweden) with implanted measuring stem embedded in gelatine was developed. The gelatine mixture was chosen in such a way that assembly forces applied to the model corresponded to those in situ. A study involving 31 surgeons was carried out on the aforementioned in vitro model, in which the assembly forces were determined. Results A model was developed, with the influence of human soft tissues being taken into account. The assembly forces measured on the in vitro model were, on average, 2037.2 N ± 724.9 N, ranging from 822.5 N to 3835.2 N. The comparison among the surgeons showed no significant differences in sex (P = 0.09), work experience (P = 0.71) and number of THAs performed per year (P = 0.69). Conclusions All measured assembly forces were below 4 kN, which is recommended in the literature. This could lead to increased corrosion following fretting in the head-neck interface. In addition, there was a very wide range of assembly forces among the surgeons, although other influencing factors such as different implant sizes or materials were not taken into account. To ensure optimal assembly force, the impaction should be standardized, e.g., by using an appropriate surgical instrument.

Sustaining Research-Based Practices in Reading

1999 ◽  
Vol 20 (5) ◽  
pp. 263-287 ◽  
Author(s):  
Janette K. Klingner ◽  
Sharon Vaughn ◽  
Marie Tejero Hughes ◽  
Maria Elena Arguelles
Keyword(s):  
Instructional Practices ◽  
High Rate ◽  
Strategic Reading ◽  
School Year ◽  
Wide Range ◽  
Sustained Use ◽  
Development Experience ◽  
Collaborative Strategic Reading ◽  
Research Based Practices ◽  
Over Time

This study examined the extent to which the reading instructional practices learned by a cohort of teachers who participated in an intensive, yearlong professional development experience during the 1994-1995 school year have been sustained and modified over time. Teachers learned three multileveled practices—partner reading, collaborative strategic reading, and making words—that promote gains in reading for students from a wide range of achievement levels. Teachers were observed and interviewed 3 years later to determine the extent to which they continued to implement the practices, the ways in which they modified them, and factors that influenced their sustained use of the practices. With the exception of one teacher, all the teachers sustained one or more of the three practices at a high rate.

Multivariate design and analysis of aircraft HEX under multiple working conditions within flight envelope

2021 ◽  
pp. 1-18
Author(s):  
Qihang Liu ◽  
G.Q. Xu ◽  
Jie Wen ◽  
Yanchen Fu ◽  
Laihe Zhuang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Working Conditions ◽  
Design Method ◽  
Structural Parameters ◽  
Optimal Structure ◽  
Clear Correlation ◽  
Pressure Drops ◽  
Design Variables ◽  
Wide Range ◽  
Common Weight

Abstract This paper presents a multi-condition design method for the aircraft heat exchanger (HEX), marking with light weight, compactness and wide range of working conditions. The quasi-traversal genetic algorithm (QT-GA) method is introduced to obtain the optimal values of five structural parameters including the height, the tube diameter, the tube pitch, and the tube rows. The QT-GA method solves the deficiency of the conventional GA in the convergence, and gives a clear correlation between design variables and outputs. Pressure drops, heat transfer and the weight of the HEX are combined in a single objective function of GA in the HEX design, thus the optimal structure of the HEX suitable for all the working conditions can be directly obtained. After optimization, the weight of the HEX is reduced to 2.250 kg, more than 20% lower than a common weight of around 3 kg. Based on the optimal structure, the off-design performance of the HEX is further analyzed. Results show that the extreme working conditions for the heat transfer and the pressure drops are not consistent. It proves the advance of the multi-condition design method over traditional single-condition design method. In general, the proposed QT-GA design method is an efficient way to solve the multi-condition problems related to the aircraft HEX or other energy systems.

MAIN FEATURES AND TRENDS OF DEVELOPMENT OF THE SERVICE MARKET

2017 ◽  
Author(s):  
Larysa Getman ◽  
Keyword(s):  
Customer Loyalty ◽  
Consumer Choice ◽  
Information Technologies ◽  
Service Sector ◽  
Supply And Demand ◽  
High Rate ◽  
Barriers To Entry ◽  
Relevant Market ◽  
Service Market ◽  
Wide Range

The article discusses approaches to the interpretation of the concept of a service, its specific differences from a physical product and the main features as an object of purchase and sale in the relevant market. Based on the analysis and systematization of existing scientific views, the main features of the service market and the features of the interaction of supply and demand in the service sector are revealed. The practice of functioning of the service market demonstrates the high dynamics of market processes, a pronounced segmentation of demand for services, a high degree of differentiation of services, a high rate of capital turnover and the important role of non-price barriers to entry into the market. The essence and value of the customer's customer loyalty for successful commercial activities and increasing the competitiveness of the manufacturer-supplier of the service has been investigated. Loyalty becomes an indicator of business performance and its ability to innovate. A customer-oriented business philosophy, where a wide range of factors of influence on the formation of customer loyalty is taken into account and used, will allow the company to count on long-term relationships with the consumer and will attract new customers through his positive experience. The possibilities and features of the application of competitive strategies by firms in the field of service activities were analyzed. The main trends in the development of the services market in the current stage, namely the processes of its digitalization, have been investigated. The buyer today is interested not only in price and quality, but also in good service. If a company meets customer service demand through the introduction of chat bots, self- service terminals, mobile applications, etc., then this contributes to the formation of a positive customer experience, which ultimately increases sales. The features and advantages of using information technologies both in business activities and in the implementation of consumer choice have been determined.

scholarly journals Redefining Knee Balance in a Medially Stabilized Prosthesis: An In-Vitro Study

2017 ◽  
Vol 11 (1) ◽  
pp. 1165-1172
Author(s):  
Philippe Van Overschelde ◽  
Vera Pinskerova ◽  
Peter P. Koch ◽  
Christophe Fornasieri ◽  
Sandro Fucentese
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
In Vitro Study ◽  
Lateral Release ◽  
Soft Tissue Release ◽  
Iliotibial Band ◽  
Soft Tissue Envelope ◽  
Medial Side ◽  
Fresh Frozen

Background: To date, there is still no consensus on what soft tissues must be preserved and what structures can be safely released during total knee arthroplasty (TKA) with a medially stabilized implant. Objective: The aim of this study was to analyze the effect of a progressive selective release of the medial and lateral soft tissues in a knee implanted with a medially stabilized prosthesis. Method: Six cadaveric fresh-frozen full leg specimens were tested. In each case, kinematic pattern and mediolateral laxity were measured in three stages: firstly, prior to implantation; secondly, after the implantation of the trial components, but before any soft tissue release; and thirdly, progressively as soft tissue was released with the trial implant in place. The incremental impact of each selective release on knee balance was then analyzed. Results: In all cases sagittal stability was not affected by the progressive release of the lateral soft tissue envelope. It was possible to perform progressive lateral release provided the anterior one-third of the iliotibial band (ITB) remained intact. Progressive medial release could be performed on the medial side provided the anterior fibers of the superficial medial collateral ligament (sMCL) remained intact. Conclusion: The medially conforming implant remains stable provided the anterior fibers of sMCL and the anterior fibers of the ITB remain intact. The implant’s sagittal stability is mainly dependent on its medial ball-in-socket design.

scholarly journals Massive Pseudotumor in a 28mm Ceramic-Polyethylene Revision THA: A Case Report

2014 ◽  
Vol 4 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Edward McPherson, M.D., FACS ◽  
Matthew Dipane, BA ◽  
Sherif Sherif, MD
Keyword(s):  
Soft Tissues ◽  
Polyethylene Wear ◽  
Femoral Stem ◽  
High Rate ◽  
Zirconia Ceramic ◽  
Porous Coating ◽  
Metal Debris ◽  
Ultrafine Metal Particles ◽  
Revision Tha ◽  
Therapeutic Study

This report reviews the findings of a massive pseudotumor detected pre-operatively in a 13-year-old revision total hip arthroplasty. The case is unique in that the bearing involved was a 28mm zirconia ceramic head on a polyethylene liner. We propose that the pseudotumor arose from ultrafine titanium particles liberated from the proximal porous coating of the femoral stem. We suspect that the osteolysis produced from polyethylene wear exposed the proximal porous coating and, via a process of mechanical abrasion with the surrounding soft tissues, liberated ultrafine titanium particles. We believe the pseudotumor formed because the patient was pre-sensitized to metal debris based upon a pre-operative lymphocyte T-cell proliferation test (LTT). Based upon this unique case, we feel that pseudotumors more likely form when there is a high rate of ultrafine metal particles generated in a pre-sensitized patient. Finally, we introduce what we believe are the main biologic wear responses in THA. Further research is needed to validate this proposed model.Keywords: pseudotumor, ceramic, polyethylene, osteolysis, THA, bearing wear eesponse, titanium debrisLevel of Evidence:  AAOS Therapeutic Study Level IV

Expression of Transgelin in Triple Negative and Non Triple Negative Breast Cancer: A Differential Study

2020 ◽  
Vol 106 (1_suppl) ◽  
pp. 20-20
Author(s):  
NS Tolba ◽  
AS Alsedfy ◽  
SW Skandar ◽  
YM El-Kerm
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Molecular Subtypes ◽  
High Rate ◽  
Targeted Treatment ◽  
Her2 Status ◽  
Altered Expression ◽  
Wide Range ◽  
Significant Difference

Introduction: Triple negative breast cancer (TNBC) is defined by the absence of ER expression, PR expression and HER2 amplification. No targeted treatment is available for TNBC and chemotherapy remains the best therapeutic option. However, in the case of recurrence or chemo-resistance, therapeutic options are very limited. TNBC presents a high rate of proliferation and is highly aggressive having low survival rate. As the complexity of this disease is being simplified over time, new targets are also being discovered for the treatment of this disease. Therefore, there is still need for new biomarkers, which would serve for targeted treatment. Transgelin was proposed as a new potential cancer biomarker. Altered expression of Transgelin has been described in a wide range of cancers, often with contradictory results. The aim of the study was to compare Transgelin expression across molecular subtypes of breast cancer, to identify if it can be used as a future molecular targeted protein for TNBC. Material and Methods: Transgelin immunohistochemistry was applied on 60 retrospectively collected paraffin blocks of patients presenting with invasive breast carcinoma (NST) having different molecular subtypes. Blocks were collected between 2015 and 2016 from Pathology department, Medical Research Institute, Egypt. Her2 equivocal cases were excluded from the study. Results: Transgelin expression was positive in 23 cases and negative in 37 cases. There was a statistically significant difference between (Transgelin +) and (Transgelin -) cases being highly expressed in TNBC in comparison to other molecular subtypes. It was also highly expressed in tumors with large size, high grade, positive lymph-vascular invasion status & lymph node metastasis. There was no statistically significant difference between (Transgelin+) and (Transgelin-) as regards age and Her2 status. Conclusions: Transgelin is an aggressive biomarker differentially expressed among the molecular breast cancer subtypes with high expression in TNBC. Transgelin may provide a potential target for future treatment of TNBC.

scholarly journals Late Abduction Deformity of the Midfoot Following the “Medial Double” (Diple) Procedure for Hindfoot Valgus Deformity

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0029
Author(s):  
Arthur Manoli
Keyword(s):  
Valgus Deformity ◽  
High Rate ◽  
Joint Involvement ◽  
Bone Block ◽  
Lateral Side ◽  
Triple Arthrodesis ◽  
Lateral Column ◽  
Calcaneocuboid Joint ◽  
Lateral Incision ◽  
Hindfoot Deformity

Category: Hindfoot Introduction/Purpose: There has been considerable interest in recent years in performing a combined talonavicular and subtalar arthrodesis instead of a standard triple arthrodesis for a rigid hindfoot deformity. The ”medial double” (diple) avoids fusing the calcaneocuboid joint with its lateral incision, common bone block graft and high rate of complications. Although the results of the “medial double” are generally satisfactory, there are no reports of late midfoot abduction deformity, although it was predicted by Evans in 1975. Methods: A 79 year-old-male with long-standing skin psoriasis with joint involvement presented with severe bilateral flatfoot deformities. The left hindfoot was arthritic, deformed and painful. Despite a conservative course of orthotics and ankle braces, the pain persisted. Because there was a psoriatic plaque over the lateral side of the foot, it was decided to perform a ”medial double” arthrodesis with screw fixation, a plantarflexing 1st tarsometatarsal joint fusion for medial column stabilization, and a heel cord lengthening Results: Skin and bony healing were uneventful. Over the subsequent three years a progressive abduction deformity developed through the naviculocuneiform joints and the unfused calcaneocuboid joint. The patient had only occasional pain in the midfoot and wore wide shoewear to accommodate the deformity. Conclusion: A late abduction deformity can develop through the midfoot in patients who have the ‘medial double” procedure for hindfoot valgus. The cuboid settles proximally against the short distal calcaneus, and the naviculocuneiform joints sublux laterally. In patients with hindfoot valgus with severe lateral column shortening secondary to calcaneocuboid joint remodeling, it may be better to perform an actual triple arthrodesis with a bone graft in the calcaneocuboid joint instead of a “medial double.” Alternatively, one could add a naviculocuneiform arthrodesis to the ”medial double” arthrodesis to prevent this complication.

scholarly journals Two-millimetre diameter operative arthroscopy of the ankle is safe and effective

2020 ◽  
Vol 28 (10) ◽  
pp. 3080-3086 ◽  
Author(s):  
Tobias Stornebrink ◽  
J. Nienke Altink ◽  
Daniel Appelt ◽  
Coen A. Wijdicks ◽  
Sjoerd A. S. Stufkens ◽  
...  
Keyword(s):  
Articular Surface ◽  
Anteromedial Portal ◽  
Human Donor ◽  
Articular Surfaces ◽  
Iatrogenic Damage ◽  
Anterolateral Portal ◽  
Fresh Frozen ◽  
Effective Visualization ◽  
Neurovascular Structures ◽  
Portal Tracts

Abstract Purpose Technical innovation now offers the possibility of 2-mm diameter operative arthroscopy: an alternative to conventional arthroscopy that no longer uses inner rod-lenses. The purpose of this study was to assess whether all significant structures in the ankle could be visualized and surgically reached during 2-mm diameter operative arthroscopy, without inflicting iatrogenic damage. Methods A novel, 2-mm diameter arthroscopic system was used to perform a protocolled arthroscopic procedure in 10 fresh-frozen, human donor ankles. Standard anteromedial and anterolateral portals were utilized. Visualization and reach with tailored arthroscopic instruments of a protocolled list of articular structures were recorded and documented. A line was etched on the most posterior border of the talar and tibial cartilage that was safely reachable. The specimens were dissected and distances between portal tracts and neurovascular structures were measured. The articular surfaces of talus and tibia were photographed and inspected for iatrogenic damage. The reachable area on the articular surface was calculated and analysed. Results All significant structures were successfully visualized and reached in all specimens. The anteromedial portal was not in contact with neurovascular structures in any specimen. The anterolateral portal collided with a branch of the superficial peroneal nerve in one case but did not cause macroscopically apparent harm. On average, 96% and 85% of the talar and tibial surfaces was reachable respectively, without causing iatrogenic damage. Conclusion 2-mm diameter operative arthroscopy provides safe and effective visualization and surgical reach of the anterior ankle joint. It may hold the potential to make ankle arthroscopy less invasive and more accessible.

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