We developed an augmented reality (AR)-based portable navigation system in which the surgeon can view the pelvic plane and placement angle of an acetabular cup on the display of a smartphone during ...THA.
(1) Is acetabular component placement more accurate using the AR-based portable navigation system compared with the conventional freehand technique? (2) Is intraoperative measurement of placement angle more accurate when using the AR-based portable navigation system compared with a goniometer?
Forty-six patients were randomly assigned to undergo acetabular cup placement during THA using the AR-based portable navigation system (AR navigation group) or placement of a mechanical alignment guide (conventional group). All surgeries were performed with the patient in the lateral decubitus position. We compared the absolute value of the difference between the targeted placement angle and postoperative measured placement angle between the groups using two types of imaging (radiography and CT).
In terms of radiographic inclination, the mean differences between the targeted placement angle and postoperative measured angle were smaller in the AR navigation group than in the conventional group for both radiographs and CT images (2.3° ± 1.4° versus 3.9° ± 2.4°, respectively; p = 0.009 and 1.9° ± 1.3° versus 3.4° ± 2.6°, respectively; p = 0.02). There were no differences in radiographic anteversion between the two groups. No complications were associated with the use of the AR-based portable navigation system.
This system yielded no differences in acetabular anteversion accuracy, and no clinically important differences in acetabular inclination. Therefore, at this time we cannot recommend this device as its costs and risks cannot be justified based on the absence of a clinically meaningful difference in cup placement accuracy. Although we detected no complications, this was a small series, and this approach adds both surgical time and pins in the ilium.
Level I, therapeutic study.
We developed an acetabular cup placement device, the AR-HIP system, using augmented reality (AR). The AR-HIP system allows the surgeon to view an acetabular cup image superimposed in the surgical ...field through a smartphone. The smartphone also shows the placement angle of the acetabular cup. This preliminary study was performed to assess the accuracy of the AR-HIP system for acetabular cup placement during total hip arthroplasty (THA).
We prospectively measured the placement angles using both a goniometer and AR-HIP system in 56 hips of 54 patients undergoing primary THA. We randomly determined the order of intraoperative measurement using the 2 devices. At 3 months after THA, the placement angle of the acetabular cup was measured on computed tomography images. The primary outcome was the absolute value of the difference between intraoperative and postoperative computed tomography measurements.
The measurement angle using AR-HIP was significantly more accurate in terms of radiographic anteversion than that using a goniometer (2.7° vs 6.8°, respectively; mean difference 4.1°; 95% confidence interval, 3.0-5.2; P < .0001). There was no statistically significant difference in terms of radiographic inclination (2.1° vs 2.6°; mean difference 0.5°; 95% confidence interval, −1.1 to 0.1; P = .13).
In this pilot study, the AR-HIP system provided more accurate information regarding acetabular cup placement angle than the conventional method. Further studies are required to confirm the utility of the AR-HIP system as a navigation tool.
Abstract
Glycans serve important roles in signaling events and cell-cell communication, and they are recognized by lectins, viruses and bacteria, playing a variety of roles in many biological ...processes. However, there was no system to organize the plethora of glycan-related data in the literature. Thus GlyTouCan (https://glytoucan.org) was developed as the international glycan repository, allowing researchers to assign accession numbers to glycans. This also aided in the integration of glycan data across various databases. GlyTouCan assigns accession numbers to glycans which are defined as sets of monosaccharides, which may or may not be characterized with linkage information. GlyTouCan was developed to be able to recognize any level of ambiguity in glycans and uniquely assign accession numbers to each of them, regardless of the input text format. In this manuscript, we describe the latest update to GlyTouCan in version 3.0, its usage, and plans for future development.
Osteoarthritis (OA) is a risk factor for falls. To decrease the fall risk, it is important to evaluate the detailed features of the gait of patients with OA. This study aimed to investigate the ...spatio-temporal parameters of gait in patients with end-stage hip OA, especially foot trajectory. We measured normal speed gait in patients with hip OA and in healthy controls (HCs) using inertial measurement units attached to shanks. The stride lengths in the affected and unaffected sides in the patients with hip OA were shorter than those in the HCs, but the position of maximum foot clearance was not significantly different between the two groups. The patients with hip OA compensated the position of maximum foot clearance to avoid fall risk. The horizontal plane foot trajectory in patients with hip OA suggests that the lateral bending of the trunk during walking, which is frequently seen in them, was a result of the lateral distance at swing down being located significantly more medially on the unaffected side than on the affected side. Herein, a new gait parameter of lateral distance at swing was discovered by a detailed evaluation of three-dimensional foot trajectory of female patients with end-stage hip OA.
•Joining between porous aluminum and resin can be achieved by friction welding.•Joining can be achieved without collapse of porous aluminum.•The joining strength was similar to strength of mother ...materials.
Composite materials consisting of porous aluminum and resin are expected to meet the current demand for the weight reduction of parts. The objective of this study is to introduce friction welding for joining porous aluminum and a polycarbonate plate. The advantages of friction welding are that it is a simple process and the joining surface is locally and directly heated by the friction heat generated between the porous aluminum and the polycarbonate plate. We showed that joining of porous aluminum and a polycarbonate plate can be achieved by friction welding via the anchor effect without the collapse of pores. The observed joining strength was similar to the strength of the porous aluminum itself.
In life science fields, database integration is progressing and contributing to collaboration between different research fields, including the glycosciences. The integration of glycan databases has ...greatly progressed collaboration worldwide with the development of the international glycan structure repository, GlyTouCan. This trend has increased the need for a tool by which researchers in various fields can easily search glycan structures from integrated databases. We have developed a web-based glycan structure search tool, SugarDrawer, which supports the depiction of glycans including ambiguity, such as glycan fragments which contain underdetermined linkages, and a database search for glycans drawn on the canvas. This tool provides an easy editing feature for various glycan structures in just a few steps using template structures and pop-up windows which allow users to select specific information for each structure element. This tool has a unique feature for selecting possible attachment sites, which is defined in the Symbol Nomenclature for Glycans (SNFG). In addition, this tool can input and output glycans in WURCS and GlycoCT formats, which are the most commonly-used text formats for glycan structures.
GlyTouCan version 1.0 was released in 2015 as the international glycan structure repository, and a new sequence format called WURCS (Web3 Unique Representation of Carbohydrate Structures) was ...proposed during the early stages of the GlyTouCan project. GlyTouCan uses WURCS as its base representation for glycans because existing formats were insufficient in their flexibility to represent any and all glycans universally. Therefore, in order to obtain WURCS strings for existing or new glycan structures, conversion tools or glycan structure editors that can export WURCS became necessary. GlycanBuilder was an obvious choice to extend due to its wide usage by the community. However, GlycanBuilder was limited because it was originally developed to support mammalian glycans. It also did not support the newly proposed monosaccharide symbol standard called Symbol Nomenclature for Glycans (SNFG). Therefore in this work, we implemented a new version of GlycanBuilder to greatly increase its usability. The glycan rendering system was refactored so that cyclic glycans, nested repeating units, monosaccharide compositions and cross-linked glycan structures can be represented. Both import and export utilities for WURCS were also implemented and SNFG symbols were incorporated to allow glycans to be exported as graphics using the latest glycan symbol nomenclature.
This new version of GlycanBuilder called “GlycanBuilder2”, is able to support a wide variety of ambiguous glycans, including structures containing monosaccharides from bacteria and plants. These glycans can also be displayed using the new SNFG symbols. This tool can aid researchers in communicating about the complex, diverse, and ambiguous structures of glycans more rapidly. Moreover, the new GlycanBuilder can now easily output WURCS sequences from glycans drawn on the canvas. Most importantly, because GlyTouCan employs WURCS as the basic format for registration and searching of glycan information, a wider variety of glycans can now be readily registered and queried in GlyTouCan.
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•Implemented the new GlycanBuilder to support a wide variety of ambiguous glycans.•Ambiguous glycans such as cyclic and cross-linked structures can be drawn.•Updated to handle the newly proposed monosaccharide symbol called SNFG.•The new GlycanBuilder can visualize glycan images from WURCS strings.•The new GlycanBuilder can output WURCS sequences from glycans drawn on the canvas.
Total hip arthroplasty (THA) is performed for pain relief in patients with osteoarthritis of the hip joint. After THA, patients may recover muscle mass and physical function. Muscle quality is the ...main parameter used to indicate intramuscular fat content, and it is related with muscle function in older individuals. However, how THA affects muscle quality, as determined by echo intensity (EI), is not well understood. The purpose of this study was to determine the long-term characteristics of EI, muscle quantity, muscle function, and physical functions in the patients with THA surgery. In order to achieve the purpose, we performed two comparison. First, we compared muscle EI, quantity and function in operated leg with unoperated legs in the same patients and with the legs of healthy adults (i.e., both unoperated legs). Second, we compared physical functional tests between THA patient and age and body composition matched controls. Twenty-two older individuals (age: 67.1 ± 5.3 years, height: 160.9 ± 7.1 cm, body mass: 62.6 ± 16.1 kg) who underwent unilateral THA several (5.2 ± 3.1) years ago (THA group) and 22 healthy controls with matching age and body composition (age: 68.3 ± 4.4 years, height: 160.3 ± 7.9 cm, body mass: 61.7 ± 7.8 kg) (CON group) participated in this case-control study. EI, an index of muscle quality, and muscle thickness (MT), an index of muscle quantity, were measured from B-mode transverse images of the rectus femoris obtained through ultrasound. The maximal isometric knee extension torque was measured in both the operated and unoperated legs in the THA group and in the right leg in the CON group (control leg); physical function tests, such as sit-to-stand, walking speed, hip adduction, and abduction torque assessments, were performed in both groups. MT and maximal isometric knee extension torque in operated leg were not different with unoperated, and control legs; the EI in the operated leg was significantly higher than that in the control leg (106.9 ± 16.9 vs. 92.4 ± 21.0 a.u., P < 0.05). The THA group demonstrated slower walking speed and lower hip abduction torque than the CON group (walking speed: 1.3 ± 0.2 vs. 1.5 ± 0.2 m/s; hip abduction torque 1.2 ± 0.3 vs. 1.5 ± 0.5 Nm/kg, P < 0.05). Several years after THA, the operated legs completely recovered the same level of muscle quantity as that in healthy participants but with lower muscle quality and hip joint function. These defects may be associated with locomotive dysfunction in older THA patients.
•Total hip arthroplasty (THA) has been attempted in older with osteoarthritis.•Muscle echo intensity of the operated leg in THA was higher than that of the control leg in healthy.•Muscle thickness and functional parameters were similar among the operated, unoperated, and control legs.•THA group had lower hip abduction torque and slower walk speed than healthy group.
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