scholarly journals Reliability of an Integrated Ultrasound and Stereophotogrammetric System for Lower Limb Anatomical Characterisation

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Frederick Greatrex ◽  
Erica Montefiori ◽  
Thomas Grupp ◽  
Josef Kozak ◽  
Claudia Mazzà
Keyword(s):  
Healthy Subjects ◽  
Combined Use ◽  
Flexion Extension ◽  
Length Measurements ◽  
Preoperative Procedures ◽  
Total Knee ◽  
Ultrasound System ◽  
Knee And Hip Arthroplasty ◽  
Clinical Adoption

Background. Lower extremity analysis for preoperative total knee and hip arthroplasty routines can increase surgery success rate and hence reduce associated costs. Current tools are limited by being invasive, limited to supine analysis, or too expensive. This study aimed to propose and validate a device, OrthoPilot®, based on the combined use of a stereophotogrammetric and ultrasound system which can in vivo and noninvasively measure varus/valgus, flexion/extension, femur and tibia torsion, and femur and tibia lengths.Methods. A phantom was measured by four operators to determine the resolution of the system. Interoperator variability was measured on three operators who measured the above six variables on both legs of three subjects in standing and supine positions. Intraoperator variability was assessed on data from three repeats from 9 subjects (18 legs).Results. All 6 variables were reliably detected on a phantom, with a resolution of 1 mm and 0.5°. Inter- and intraoperator consistency was observed for varus/valgus, flexion/extension, and length measurements on the healthy subjects in standing and supine positions (all ICC > 0.93). For torsion measurements, there was a considerable variation.Conclusion. The proposed system, when used on healthy subjects, allowed reliable measurements of key parameters for preoperative procedures in both supine and standing positions. Accuracy testing and further validation on patient populations will be the next step toward its clinical adoption.

In vivo kinematics of deep lunges and sit-to-stand activities in patients with bicruciate-retaining total knee arthroplasty

2020 ◽  
Vol 102-B (6_Supple_A) ◽  
pp. 59-65
Author(s):  
Young-Min Kwon ◽  
Paul Arauz ◽  
Yun Peng ◽  
Christian Klemt
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Cruciate Ligaments ◽  
In Vivo Kinematics ◽  
Contralateral Knee ◽  
Sit To Stand ◽  
Flexion Extension ◽  
Total Knee ◽  
Bcr Tka

Aims The removal of the cruciate ligaments in total knee arthroplasty (TKA) has been suggested as a potential contributing factor to patient dissatisfaction, due to alteration of the in vivo biomechanics of the knee. Bicruciate retaining (BCR) TKA allows the preservation of the cruciate ligaments, thus offering the potential to reproduce healthy kinematics. The aim of this study was to compare in vivo kinematics between the operated and contralateral knee in patients who have undergone TKA with a contemporary BCR design. Methods A total of 29 patients who underwent unilateral BCR TKA were evaluated during single-leg deep lunges and sit-to-stand tests using a validated computer tomography and fluoroscopic imaging system. In vivo six-degrees of freedom (6DOF) kinematics were compared between the BCR TKA and the contralateral knee. Results During single-leg deep lunge, BCR TKAs showed significantly less mean posterior femoral translation (13 mm; standard deviation (SD) 4) during terminal flexion, compared with the contralateral knee (16.6 mm, SD 3.7; p = 0.001). Similarly, BCR TKAs showed significantly less mean femoral rollback (11.6 mm (SD 4.5) vs 14.4 mm (SD 4.6); p < 0.043) during sit-to-stand. BCR TKAs showed significantly reduced internal rotation during many parts of the strenuous flexion activities particularly during high-flexion lunge (4° (SD 5.6°) vs 6.5° (SD 6.1°); p = 0.051) and during sit-to-stand (4.5° (SD 6°) vs 6.9° (SD 6.3°); p = 0.048). Conclusion The contemporary design of BCR TKA showed asymmetrical flexion-extension and internal-external rotation, suggesting that the kinematics are not entirely reproduced during strenuous activities. Future studies are required to establish the importance of patient factors, component orientation and design, in optimizing kinematics in patients who undergo BCR TKA. Cite this article: Bone Joint J 2020;102-B(6 Supple A):59–65.

Validation of three-dimensional total knee replacement kinematics measurement using single-plane fluoroscopy

2016 ◽  
Vol 7 (1) ◽  
pp. 14
Author(s):  
R. Daems ◽  
Jan Victor ◽  
Patrick De Baets ◽  
S. Van Onsem ◽  
Matthias Verstraete
Keyword(s):  
Motion Tracking ◽  
Sagittal Plane ◽  
Tracking System ◽  
Knee Kinematics ◽  
In Vivo Evaluation ◽  
Single Plane ◽  
Validation Experiment ◽  
Flexion Extension ◽  
Total Knee

Instability of the knee after total knee arthroplasty (TKA) is today the number one reason for aseptic revision surgery. In vivo evaluation of knee kinematics using single-plane fluoroscopy has become an important method to investigate knee stability and compare dierent implant designs. A validation experiment was performed to assess the accuracy of this method. A total knee implant was installed on sawbones and a flexion extension movement was performed with the sagittal plane parallel to the detector panel of the fluoroscope. Simultaneously, the sawbones were tracked using a conventional motion tracking system and rigidly attached markers. That measurement can be seen as a golden standard and is therefore believed to represent the real positions. The results indicate that knee rotations can be measured with an accuracy of approximately 0.6 and sagittal plane translations can be measured with an accuracy of approximately 0.4 mm. These results prove that the method is sufficiently accurate for clinical use.

A Best-Fit of an Anatomic Tibial Baseplate Closely Parallels the Flexion-Extension Plane and Covers a High Percentage of the Proximal Tibia

2020 ◽  
Author(s):  
Alexander J. Nedopil ◽  
Tomas Zamora ◽  
Trevor Shelton ◽  
Stephen M. Howell ◽  
Maury Hull
Keyword(s):  
Proximal Tibia ◽  
Mean Deviation ◽  
Cross Sectional ◽  
Primary Tkas ◽  
Flexion Extension ◽  
Total Knee ◽  
The Mean ◽  
Best Fit ◽  
Anterior Posterior

AbstractThere are no reports of in vivo internal–external (I–E) rotational alignment and coverage of the proximal tibia after performing a best-fit method of an anatomically designed and asymmetrically shaped tibial baseplate during calipered kinematically aligned (KA) total knee arthroplasty (TKA). We hypothesized that a best-fit plane sets the anterior–posterior (A–P) axis of the anatomic baseplate closely parallel to the flexion–extension (F–E) plane of the knee and covers a high percentage of the proximal tibia. A total of 145 consecutive primary TKAs were prospectively collected. The calipered KA method and verification checks set the positions and orientations of the components without ligament release in all knees without restrictions on the preoperative deformities. A best-fit method selected one of six trials of anatomic baseplates that maximized coverage and set I–E rotation parallel to and within the cortical edge of the proximal tibia. The angle between the transverse axes of the components (i.e., the deviation of the A–P axis of the anatomic baseplate from the F–E plane of the native knee) and the cross-sectional area (CSA) of the proximal tibia were measured on postoperative computerized tomographic scans. The mean deviation of the anatomic baseplate from the F–E plane was 2-degree external ± 5 degrees. The mean coverage of the proximal tibia was 87 ± 6% (CSA of baseplate from the manufacturer/CSA of proximal tibia × 100). The anatomic baseplate and best-fit method adequately set I–E rotation of the baseplate closely parallel to the F–E plane of the knee and cover a high percentage of the proximal tibia.

scholarly journals Targeting Erbin in B cells for therapy of lung metastasis of colorectal cancer

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Tong Shen ◽  
Jing-Lin Liu ◽  
Chu-Yi Wang ◽  
Youlutuziayi Rixiati ◽  
Shi Li ◽  
...  
Keyword(s):  
B Cells ◽  
Lung Metastasis ◽  
Lung Metastases ◽  
Pdz Domain ◽  
Clinical Samples ◽  
Key Factors ◽  
Combined Use ◽  
Iga Production

AbstractThe mechanisms and key factors involved in tumor environments for lung metastasis of CRC are still unclear. Here, using clinical samples from lung metastases of CRC patients, we found that intestinal immune network for IgA production was significantly dysregulated in lung metastases of CRC. Single-cell RNA sequencing discovered a subtype of B cells positive for Erbin, one member of the leucine-rich repeat and PDZ domain (LAP) family, was involved in the lung metastases. Erbin deletion in B cells suppressed lung metastasis of CRC in vivo. And, deletion of Erbin in B cells enhanced the killing effects of CD8+ T cells on tumor cells. Mechanistically, Erbin knockout attenuated TGFβ-mediated suppression of migration of CXCR5+ IgA+ cells and STAT6-mediated PD1 expression. Our study uncovered a key role of Erbin in regulating PD1+ IgA+ B cells in lung metastasis of CRC. Targeting Erbin as well as combined use of neutralizing B cells and antibodies neutralizing PD1 suppresses lung metastasis of CRC in mice, suggesting the potential option for treatment of lung metastasis of CRC.

scholarly journals Role of Bradykinin Type 2 Receptors in Human Sweat Secretion: Translational Evidence Does Not Support a Functional Relationship

2021 ◽  
Vol 34 (3) ◽  
pp. 162-166
Author(s):  
Thad E. Wilson ◽  
Seetharam Narra ◽  
Kristen Metzler-Wilson ◽  
Artur Schneider ◽  
Kelsey A. Bullens ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Sweat Rate ◽  
Sweat Glands ◽  
Potential Therapeutic Target ◽  
Sweat Secretion ◽  
Hoe 140 ◽  
A Current

Bradykinin increases skin blood flow via a cGMP mechanism but its role in sweating in vivo is unclear. There is a current need to translate cell culture and nonhuman paw pad studies into in vivo human preparations to test for therapeutic viability for disorders affecting sweat glands. Protocol 1: physiological sweating was induced in 10 healthy subjects via perfusing warm (46–48°C) water through a tube-lined suit while bradykinin type 2 receptor (B2R) antagonist (HOE-140; 40 μM) and only the vehicle (lactated Ringer’s) were perfused intradermally via microdialysis. Heat stress increased sweat rate (HOE-140 = +0.79 ± 0.12 and vehicle = +0.64 ± 0.10 mg/cm<sup>2</sup>/min), but no differences were noted with B2R antagonism. Protocol 2: pharmacological sweating was induced in 6 healthy subjects via intradermally perfusing pilocarpine (1.67 mg/mL) followed by the same B2R antagonist approach. Pilocarpine increased sweating (HOE-140 = +0.38 ± 0.16 and vehicle = +0.32 ± 0.12 mg/cm<sup>2</sup>/min); again no differences were observed with B2R antagonism. Last, 5 additional subjects were recruited for various control experiments which identified that a functional dose of HOE-140 was utilized and it was not sudorific during normothermic conditions. These data indicate B2R antagonists do not modulate physiologically or pharmacologically induced eccrine secretion volumes. Thus, B2R agonist/antagonist development as a potential therapeutic target for hypo- and hyperhidrosis appears unwarranted.

scholarly journals Accuracy and repeatability of wrist joint angles in boxing using an electromagnetic tracking system

2019 ◽  
Vol 23 (1) ◽  
Author(s):  
Ian T. Gatt ◽  
Tom Allen ◽  
Jon Wheat
Keyword(s):  
Wrist Joint ◽  
Tracking System ◽  
Testing Procedure ◽  
Electromagnetic Tracking ◽  
Good Reliability ◽  
Flexion Extension ◽  
In Vivo Testing ◽  
Accuracy And Repeatability ◽  
Electromagnetic Tracking System

AbstractThe hand-wrist region is reported as the most common injury site in boxing. Boxers are at risk due to the amount of wrist motions when impacting training equipment or their opponents, yet we know relatively little about these motions. This paper describes a new method for quantifying wrist motion in boxing using an electromagnetic tracking system. Surrogate testing procedure utilising a polyamide hand and forearm shape, and in vivo testing procedure utilising 29 elite boxers, were used to assess the accuracy and repeatability of the system. 2D kinematic analysis was used to calculate wrist angles using photogrammetry, whilst the data from the electromagnetic tracking system was processed with visual 3D software. The electromagnetic tracking system agreed with the video-based system (paired t tests) in both the surrogate (< 0.2°) and quasi-static testing (< 6°). Both systems showed a good intraclass coefficient of reliability (ICCs > 0.9). In the punch testing, for both repeated jab and hook shots, the electromagnetic tracking system showed good reliability (ICCs > 0.8) and substantial reliability (ICCs > 0.6) for flexion–extension and radial-ulnar deviation angles, respectively. The results indicate that wrist kinematics during punching activities can be measured using an electromagnetic tracking system.

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