scholarly journals An Easy-to-Use Portable Ultrasound Based Device for the Measurement of the Pelvic Tilt

10.29007/pwhr ◽  
2018 ◽  
Author(s):  
Guillaume Dardenne ◽  
Jean-Philippe Pluchon ◽  
Aziliz Guezou-Philippe ◽  
Hoel Letissier ◽  
Chafiaa Hamitouche ◽  
...  
Keyword(s):  
Pelvic Tilt ◽  
Safe Zone ◽  
Individual Variability ◽  
Daily Activities ◽  
Patient Specific ◽  
Average Error ◽  
Portable Ultrasound ◽  
X Ray ◽  
Non Invasive ◽  
Specific Parameter

The orientation of the cup in Total Hip Arthroplasty plays a major role on the post- operative results. It has been considered for several decades that the cup should be oriented according to the safe zone defined by Lewinnek. However, this safe zone is not always suitable because of the inter-individual variability of the pelvic tilt during daily activities. We propose in this paper a non-invasive ultrasound based solution which can easily measure this patient specific parameter in order to thereafter otimise the cup orientation. The accuracy of this system was assessed with a specific pelvic phantom. A clinical pilot study was also performed on ten patients. The pelvic tilt was measured in three daily positions: the supine, sitting and standing positions. The average error was 1.15°±0.82°. The average pelvic tilt was -97.1°±28.6°, -46.3°±12.8° and -9.0°±8.3° for respectively the supine, the sitting and the standing positions. The high inter-individual variability of the pelvic tilt in different daily positions highlight the need to have a suitable device for the measurement of this patient specific parameter for THA. The proposed system is easy-to-use, portable and allows the pelvic tilt measurement in different positions without any additional x-ray radiation.

scholarly journals In-vivo precision of a non-invasive ultrasound-based device to measure pelvic tilt for THA

10.29007/ql68 ◽  
2019 ◽  
Author(s):  
Guillaume Dardenne ◽  
Jean-Philippe Pluchon ◽  
Hoel Letissier ◽  
Aziliz Guezou-Philippe ◽  
Romain Gérard ◽  
...  
Keyword(s):  
Pelvic Tilt ◽  
Intraclass Correlation ◽  
High Body Mass Index ◽  
Standing Position ◽  
Patient Specific ◽  
Non Invasive ◽  
User Expertise ◽  
Hip Kinematics ◽  
Expertise Level

The cup orientation plays a major role in the long-term implant stability following Total Hip Arthroplasty (THA). Because of the patient specific spine-hip kinematics, the safe zone introduced by Lewinnek is more and more controversial. Several solutions have been recently developed to take into account such parameter for THA but are all either invasive, difficult to use or expensive. A non-invasive ultrasound (US) based device has been recently proposed which allows the acquisition of the pelvic tilt in different daily positions. The goal of this study is to analyze the in-vivo intra and inter-observer precision of this device. Measurements were realized by three physicians on three healthy subjects having a low, medium and high Body Mass Index (BMI). Among the three physicians, there were an expert, an intermediate, and a novice user. For each subject, the pelvic tilt was measured ten times by the three physicians in the supine, standing and sitting positions. The inter and intra-observer precisions have been analyzed using the intraclass correlation coefficient (ICC) and according to the BMI, the positions and the user expertise level. The inter-observer precision was therefore excellent whatever the BMI. It was also excellent regarding the supine and the sitting positions and good concerning the standing position. The in-vivo intra-observer precision was excellent for all measurements and whatever the user’s expertise, the BMI and the positions. This study shows therefore that the precision of our system meets the clinical requirement. Introduction

scholarly journals Patient-Specific Safe Zone Based on Daily Positions and Range of Motion

10.29007/nw28 ◽  
2020 ◽  
Author(s):  
Wistan Marchadour ◽  
Guillaume Dardenne ◽  
Aziliz Guezou-Philippe ◽  
Christian Lefèvre ◽  
Eric Stindel
Keyword(s):  
Total Hip Arthroplasty ◽  
Range Of Motion ◽  
Hip Arthroplasty ◽  
Pelvic Tilt ◽  
Safe Zone ◽  
Patient Specific ◽  
Total Hip ◽  
Prosthetic Impingement ◽  
Param Eters

Cup orientation is a challenging step in total hip arthroplasty (THA), to ensure comfort of the patient and durability of the prosthesis. The safe zone defined by Lewinnek is commonly used for cup orientation, but it is nowadays being questioned because it is not patient-specific.We propose to define a new safe zone for cup orientation, that considers patient-specific parameters such as the pelvic tilt and the range of motion (ROM) of the leg.We developed a software that easily computes a unique safe zone from these param- eters in different daily positions, ensuring a cup orientation without risks of prosthetic impingement.

Range of Motion to Impingement Curves Create a New Patient-Specific Impingement-Free Zone for Acetabular Cup Placement

2021 ◽  
Author(s):  
Thomas McCarthy ◽  
Matthew Thompson ◽  
Jim Nevelos ◽  
Hytham Salem ◽  
Brandon Naylor ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Internal Rotation ◽  
Pelvic Tilt ◽  
External Rotation ◽  
Objective Assessment ◽  
Safe Zone ◽  
Patient Specific ◽  
Acetabular Cup ◽  
High Flexion ◽  
Free Zone

Introduction: The acetabular “safe zone” has recently been questioned as a reliable reference for predicting total hip arthroplasty impingement and instability as many dislocations occur within the described parameters. Recently, an improved understanding of spino-pelvic mechanics has provided surgeons useful information to both identify those at a higher risk of dislocation and, in some cases, allows altering component positioning to accommodate the patient’s individual “functional” range of motion. The purpose of this study was to create a new patient-specific impingement-free zone by considering range of motion (ROM) to prosthetic impingement for both high flexion and extension poses, thus demarcating a zone that avoids both anterior and posterior impingement, thereby creating an objective approach to identifying a patient’s ideal functional safe zone. Materials and Methods: A validated hip ROM three-dimensional simulator was utilized to create ROM-to-impingement curves for both high flexion as well as pivot and turn poses. The user imported a computerized tomography (CT) with a supine pelvic tilt (PT) value of zero and implant models (tapered wedge stem, 132° neck angle, 15° stem version, 36mm femoral head). Femur-to-pelvis relative motions were determined for three upright seated poses (femur flexed at 90° and 40° internal rotation, with 0°, 10°, and 20° posterior PT), one chair rise pose (femur flexed at 90° and 0° internal rotation, with the pelvis flexed anteriorly until the pelvis made contact with the femur), and three standing pivot and turn poses (femur set at 5° extension, and 35° external rotation, with 5° posterior PT, 0°, and 5° anterior PT). ROM-to-impingement curves for cup inclination versus anteversion were graphed and compared against the Lewinnek safe zone. Results: The ROM-to-impingement curves provide an objective assessment of potential impingement sites as they relate to femoral rotation and pelvic tilt. The area between the stand and sit curves is the impingement-free area. A sitting erect pose with a simulated stiff spine (0° PT) yielded less impingement-free combinations of cup inclination and version than poses with greater than 0° posterior pelvic tilt. Conclusion: The results demonstrate that the acetabular target zone has a relatively small margin for error between the sitting and standing ROM curves to impingement. Importantly, anterior and posterior pelvic tilt can markedly increase the risk of impingement, potentially leading to posterior or anterior dislocations, respectively. This study highlights the importance of correctly identifying the patient-specific functional range of motion to execute optimal component positioning.

X-ray microtomography

1988 ◽  
Vol 46 ◽  
pp. 998-999
Author(s):  
H.W. Deckman ◽  
B.F. Flannery ◽  
J.H. Dunsmuir ◽  
K.D' Amico
Keyword(s):  
Computed Tomography ◽  
Internal Structure ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Tissue Structure ◽  
Individual Element ◽  
X Ray ◽  
Non Invasive ◽  
Panoramic Imaging ◽  
Three Dimensional Images

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.

Diagnostic efficacy and suitability of trans-thoracic ultrasonography for pleural fluid detection – The future non-invasive gold-standard?

2020 ◽  
Vol 13 (4) ◽  
pp. 184-190
Author(s):  
Muhammad Irfan ◽  
Abdul Rasheed Qureshi ◽  
Zeeshan Ashraf ◽  
Muhammad Amjad Ramzan ◽  
Tehmina Naeem ◽  
...  
Keyword(s):  
Pleural Effusion ◽  
Diagnostic Accuracy ◽  
Pleural Fluid ◽  
Gold Standard ◽  
Pleural Effusions ◽  
Diagnostic Efficacy ◽  
Chest Sonography ◽  
X Ray ◽  
Non Invasive ◽  
Fluid Detection

ABSTRACT Background: Conventionally Pleural effusions are suspected by history of pleuritis, evaluated by physical signs and multiple view radiography. Trans-thoracic pleural aspiration is done and aspirated pleural fluid is considered the gold-standard for pleural effusion. Chest sonography has the advantage of having high diagnostic efficacy over radiography for the detection of pleural effusion. Furthermore, ultrasonography is free from radiation hazards, inexpensive, readily available  and feasible for use in ICU, pregnant and pediatric patients. This study aims to explore the diagnostic accuracy of trans-thoracic ultrasonography for pleural fluid detection, which is free of such disadvantages. The objective is to determine the diagnostic efficacy of trans-thoracic ultrasound for detecting pleural effusion and also to assess its suitability for being a non-invasive gold-standard.   Subject and Methods: This retrospective study of 4597 cases was conducted at pulmonology  OPD-Gulab Devi Teaching Hospital, Lahore from November 2016 to July 2018. Adult patients with clinical features suggesting pleural effusions were included while those where no suspicion of pleural effusion, patients < 14 years and pregnant ladies were excluded. Patients were subjected to chest x-ray PA and Lateral views and chest ultrasonography was done by a senior qualified radiologist in OPD. Ultrasound-guided pleural aspiration was done in OPD & fluid was sent for analysis. At least 10ml aspirated fluid was considered as diagnostic for pleural effusion. Patient files containing history, physical examination, x-ray reports, ultrasound reports, pleural aspiration notes and informed consent were retrieved, reviewed and findings were recorded in the preformed proforma. Results were tabulated and conclusion was drawn by statistical analysis. Results: Out of 4597 cases, 4498 pleural effusion were manifested on CXR and only 2547(56.62%) pleural effusions were proved by ultrasound while 2050 (45.57%) cases were reported as no Pleural effusion. Chest sonography demonstrated sensitivity, specificity, PPV, NPV and diagnostic accuracy 100 % each. Conclusions: Trans-thoracic ultrasonography revealed an excellent efficacy that is why it can be considered as non-invasive gold standard for the detection of pleural effusion.

The role of microRNAs in gliomas – Therapeutic implications

2020 ◽  
Vol 13 ◽  
Author(s):  
Theodora Katsila ◽  
Dimitrios Kardamakis
Keyword(s):  
Complex Disease ◽  
Malignant Gliomas ◽  
Kappa Statistic ◽  
Individual Variability ◽  
Response To Treatment ◽  
Disease Phenotype ◽  
Therapeutic Implications ◽  
Non Invasive ◽  
Gene Environment ◽  
Sas Macro

Background: Malignant gliomas constitute a complex disease phenotype that demands optimum decisionmaking. Despite being the most common type of primary brain tumors, gliomas are highly heterogeneous when their pathophysiology and response to treatment are considered. Such inter-individual variability also renders differential and early diagnosis extremely difficult. Recent evidence highlight that the gene-environment interplay becomes of fundamental importance in oncogenesis and progression of gliomas. Objective: To unmask key features of the gliomas disease phenotype and map the inter-individual variability of patients, we explore genotype-to-phenotype associations. Emphasis is put on microRNAs as they regulate gene expression, have been implicated in the pathogenesis of gliomas and may serve as theranostics, empowering non-invasive strategies (circulating free or in exosomes). Method: We mined text and omic datasets (as of 2019) and conducted a mixed-method content analysis. A novel framework was developed to meet the aims of our analysis, interrogating data in terms of content and context. We relied on literature data from PubMed/Medline and Scopus, as they are considered the largest abstract and citation databases of peer-reviewed literature. To avoid selection biases, both publicly available and private texts have been assessed. Both percent agreement and Cohen's kappa statistic have been calculated to avoid biases by SAS macro MAGREE with multicategorical ratings. Results: Gliomas serve as a paradigm for multifaceted datasets, despite data sparsity and scarcity. miRNAs and miRNAbased therapeutics are ready for prime time. Exosomal miRNAs empower non-invasive strategies, surpassing circulating free miRNAs, when accuracy and precision are considered. Conclusion: miRNAs holds promise as theranostics.

Development and Pre‐Clinical Evaluation of a Patient‐Specific High Energy X‐ray Phase Sensitive Breast Tomosynthesis System

2021 ◽  
Author(s):  
Muhammad U. Ghani ◽  
Xizeng Wu ◽  
Laurie L. Fajardo ◽  
Zhengxue Jing ◽  
Molly D. Wong ◽  
...  
Keyword(s):  
Clinical Evaluation ◽  
High Energy ◽  
Patient Specific ◽  
Breast Tomosynthesis ◽  
X Ray ◽  
Phase Sensitive
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