scholarly journals Do acetabular parameters measured on 2D imaging correlate with CT, and can lateral centre-edge angle predict femoral head coverage?

2022 ◽  
Vol 3 (1) ◽  
pp. 12-19
Author(s):  
Saif Salih ◽  
George Grammatopoulos ◽  
Sophia Burns ◽  
Margaret Hall-Craggs ◽  
Johan Witt
Keyword(s):  
Femoral Head ◽  
Linear Regression ◽  
Hip Pain ◽  
3D Analysis ◽  
3D Ct ◽  
Edge Angle ◽  
Centre Edge Angle ◽  
Ct Measurements ◽  
Lateral Centre Edge Angle ◽  
The Relationship

Aims The lateral centre-edge angle (LCEA) is a plain radiological measure of superolateral cover of the femoral head. This study aims to establish the correlation between 2D radiological and 3D CT measurements of acetabular morphology, and to describe the relationship between LCEA and femoral head cover (FHC). Methods This retrospective study included 353 periacetabular osteotomies (PAOs) performed between January 2014 and December 2017. Overall, 97 hips in 75 patients had 3D analysis by Clinical Graphics, giving measurements for LCEA, acetabular index (AI), and FHC. Roentgenographical LCEA, AI, posterior wall index (PWI), and anterior wall index (AWI) were measured from supine AP pelvis radiographs. The correlation between CT and roentgenographical measurements was calculated. Sequential multiple linear regression was performed to determine the relationship between roentgenographical measurements and CT FHC. Results CT-measured LCEA and AI correlated strongly with roentgenographical LCEA ( r = 0.92; p < 0.001) and AI ( r = 0.83; p < 0.001). Radiological LCEA correlated very strongly with CT FHC ( r = 0.92; p < 0.001). The sum of AWI and PWI also correlated strongly with CTFHC ( r = 0.73; p < 0.001). CT measurements of LCEA and AI were 3.4° less and 2.3° greater than radiological LCEA and AI measures. There was a linear relation between radiological LCEA and CT FHC. The linear regression model statistically significantly predicted FHC from LCEA, F(1,96) = 545.1 (p < 0.001), adjusted R2 = 85.0%, with the prediction equation: CT FHC(%) = 42.1 + 0.77(XRLCEA) Conclusion CT and roentgenographical measurement of acetabular parameters are comparable. Currently, a radiological LCEA greater than 25° is considered normal. This study demonstrates that those with hip pain and normal radiological acetabular parameters may still have deficiencies in FHC. More sophisticated imaging techniques such as 3D CT should be considered for those with hip pain to identify deficiencies in FHC. Cite this article: Bone Jt Open 2022;3(1):12–19.

scholarly journals Lengthening of the Normal Tibia in a Patient with Hemihypertrophy Caused by Klippel-Trenaunay-Weber Syndrome: A Case Report

2011 ◽  
Vol 19 (3) ◽  
pp. 359-363 ◽  
Author(s):  
Munetomo Takata ◽  
Koji Watanabe ◽  
Hidenori Matsubara ◽  
Kei Takato ◽  
Issei Nomura ◽  
...  
Keyword(s):  
Case Report ◽  
Femoral Head ◽  
Hip Joint ◽  
Acetabular Coverage ◽  
Leg Length ◽  
Coverage Ratio ◽  
Edge Angle ◽  
Centre Edge Angle ◽  
Weber Syndrome ◽  
Contralateral Tibia

We report a case of Klippel-Trenaunay-Weber syndrome in a 31-year-old woman who presented with hypertrophy of the left leg. She had severe osteoarthritic changes in the left hip joint secondary to the lack of acetabular coverage of the femoral head as the result of lateral inclination of the pelvis owing to leg-length discrepancy of 4 cm. The centre-edge angle (coverage ratio of the acetabulum to the femoral head) was improved from 15° to 33° after a foot lift. She underwent osteotomy and lengthening of the normal contralateral tibia using a Taylor spatial frame. Hip arthroplasty could be avoided as osteoarthritic changes of the hip joint had improved.

scholarly journals Osteophyte size and location on hip DXA scans are associated with hip pain: findings from a cross sectional study in UK Biobank

2021 ◽  
Author(s):  
Benjamin G Faber ◽  
Raja Ebsim ◽  
Fiona R Saunders ◽  
Monika Frysz ◽  
Claudia Lindner ◽  
...  
Keyword(s):  
Femoral Head ◽  
Joint Space Width ◽  
Hip Osteoarthritis ◽  
Joint Space ◽  
Cross Sectional Study ◽  
Hip Pain ◽  
Uk Biobank ◽  
Cross Sectional ◽  
Automated Method ◽  
The Relationship

Objective It remains unclear how the different features of radiographic hip osteoarthritis (rHOA) contribute to hip pain. We examined the relationship between rHOA, including its individual components, and hip pain using a novel dual-energy x-ray absorptiometry (DXA)-based method. Methods Hip DXAs were obtained from UK Biobank. An automated method was developed to obtain minimum joint space width (mJSW) from points placed around the femoral head and acetabulum. Osteophyte areas at the lateral acetabulum, superior and inferior femoral head were derived manually. Semi-quantitative measures of osteophytes and joint space narrowing (JSN) were combined to provide a measure of rHOA. Logistic regression was used to examine the relationships between these variables and hip pain, obtained via questionnaires. Results 6,807 hip DXAs were examined. rHOA was present in 353 [5.2%] individuals and was associated with hip pain [OR 2.07 (95% CI 1.54-2.80)] and hospital diagnosed OA [5.73 (2.89-11.36)]. Total osteophyte area and mJSW were associated with hip pain [1.29 (1.21-1.36), 0.84 (0.77-0.92) respectively] in unadjusted models. After mutually adjusting and adding demographic covariates, total osteophyte area continued to have strong evidence of association with hip pain [1.31 (1.23-1.39)] but mJSW did not [0.95 (0.87-1.04)]. Acetabular, superior and inferior femoral osteophyte areas were all independently associated with hip pain [1.19 (1.13-1.26), 1.22 (1.15-1.29), 1.21 (1.14-1.28) respectively]. Conclusion The relationship between DXA-derived rHOA and prevalent hip pain is explained by osteophyte area rather than mJSW. Osteophytes at different locations showed important, potentially independent, associations with hip pain, possibly reflecting the contribution of distinct biomechanical pathways.

Reliability and sensitivity of radiographic measures of hip dysplasia in childhood Charcot-Marie-Tooth disease

2021 ◽  
pp. 112070002110275
Author(s):  
Leanne N Dwan ◽  
Paul Gibbons ◽  
Kamal Jamil ◽  
David Little ◽  
Oliver Birke ◽  
...  
Keyword(s):  
Hip Dysplasia ◽  
Acetabular Index ◽  
Charcot Marie Tooth ◽  
Charcot Marie Tooth Disease ◽  
Edge Angle ◽  
Centre Edge Angle ◽  
Joint Width ◽  
Migration Percentage ◽  
Lateral Centre Edge Angle ◽  
Tooth Disease

Background: Hip dysplasia is a lack of femoral head coverage and disruption of hip and acetabular alignment and congruency, with severity ranging from mild subluxation in nascent at-risk hips to complete dislocation. Presentation of hip dysplasia in neuromuscular conditions can be sub-clinical or associated with a limp with or without hip pain, abductor and flexor weakness and reduced hip range of motion. Untreated hip dysplasia leads to early onset osteoarthritis requiring hip arthroplasty in early adulthood. Hip dysplasia occurs in 6–20% of children with Charcot-Marie-Tooth disease, however little is known about the reliability and sensitivity of detection on plain film pelvic radiographs. Methods: 14 common measures of hip dysplasia on anteroposterior pelvis radiographs were independently assessed by 2 orthopaedic specialists in 30 ambulant children with Charcot-Marie-Tooth disease. Hip health was also categorised based on clinical impression to assess the sensitivity of radiographic measures to identify hip dysplasia status. Results: 8 measures (acetabular index, head width, lateral centre-edge angle, lateral uncoverage, medial joint width, migration percentage, neck shaft angle, triradiate status) exhibited ‘excellent’ reliability between clinical evaluators. 5 of the 30 patients (17%) were identified as having nascent hip dysplasia. Reliable radiographic measures that significantly distinguished between nascent hip dysplasia and healthy hips were acetabular index, lateral centre edge angle, medial joint width and migration percentage. Conclusions: We have identified a subset of reliable and sensitive radiographic hip measures in children with Charcot-Marie-Tooth disease to prioritise during hip screening to mitigate the deleterious effects of hip dysplasia, pain and disability in adulthood.

PENGARUH HARGA DAN BRAND TRUST TERHADAP KEPUTUSAN PEMBELIAN OPPO SMARTPHONE (Studi kasus pada OPPO Store, Sinergy Celular Medan)

2019 ◽  
Vol 14 (1) ◽  
pp. 17
Author(s):  
Andi S Tarigan ◽  
Zulkarnaian Siregar
Keyword(s):  
Data Analysis ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Coefficient Of Determination ◽  
Purchase Decision ◽  
Brand Trust ◽  
Significance Level ◽  
Research Hypothesis ◽  
Analysis Technique ◽  
The Relationship

AbstrakPenelitian ini bertujuan untuk mengetahui Pengaruh Harga dan Brand Trust Terhadap Keputusan Pembelian pada Sinergy Celular Medan.Sampel dalam penelitian ini adalah seluruh pengunjung Sinergy Celular Medan sebanyak 77 orang.Teknik pengumpulan data yang digunakan adalah melalui kuesioner (angket) yaitu dengan cara menyebarkan kuesioner kepada sampel (responden) dan mengumpulkannya kembali. Teknik analisis data yang digunakan adalah Regresi Linear Berganda.Sebelum data diregresikan maka terlebih dahulu di uji keterkaitannya antara variabel, datanya diuji menggunakan uji normalitas data, multikolinearitas, dan heterokedastisitas.Serta untuk mengetahui kontribusi faktor Harga dan Brand TrustTerhadap Keputusan Pembelian digunakan rumus Koefisien Determinasi (R2). Hipotesis penelitian diterima apabila t hitung >  t tabel dengan tingkat signifikansi 0,1. Nilai t tabel dalam penelitian ini 1,993. Nilai t hitung variabel X1 sebesar 2,107 t hitung lebih besar dari t tabel maka hipotesis di terima, nilai t hitung variabel X2   sebesar 3,405 t hitung lebih besar dari t tabel maka hipotesis di terima. Kata kunci: Harga, Brand Trust, Keputusan Pembelian AbstractThis study aims to determine the Influence of Price and Brand Trust on Purchasing Decision at Sinergy Celular Medan. The sample in this study is all visitors Sinergy Celular Medan as many as 77 people.Data collection technique used is through questionnaire (questionnaire) that is by distributing questionnaires to the sample (respondent) and collect it back. Data analysis technique used is Multiple Linear Regression. Before the data is diregresikan then first in the test the relationship between variables, the data tested using the test of data normality, multicollinearity, and heterokedastisitas. And to know the contribution of price factors and Brand Trust Against Purchase Decision is used the formula Coefficient of Determination (R2). Research hypothesis accepted if t arithmetic> t table with significance level 0,1. The value of t table in this study is 1,993. Value t arithmetic variable X1 of 2.107 t arithmetic greater than t table then the hypothesis received, the value of t arithmetic variable X2 of 3.405 t arithmetic greater than t table then the hypothesis received. Keywords: Price, Brand Trust, Purchase Decision

The Influences of Palindromes in mRNA on Protein Folding Rates

2020 ◽  
Vol 27 (4) ◽  
pp. 303-312 ◽  
Author(s):  
Ruifang Li ◽  
Hong Li ◽  
Sarula Yang ◽  
Xue Feng
Keyword(s):  
Protein Folding ◽  
Regression Analysis ◽  
Linear Regression ◽  
Linear Regression Analysis ◽  
Folding Rate ◽  
Folding Rates ◽  
Negative Linear Correlation ◽  
Protein Folding Rate ◽  
The Relationship ◽  
Structure Environment

Background: It is currently believed that protein folding rates are influenced by protein structure, environment and temperature, amino acid sequence and so on. We have been working for long to determine whether and in what ways mRNA affects the protein folding rate. A large number of palindromes aroused our attention in our previous research. Whether these palindromes do have important influences on protein folding rates and what’s the mechanism? Very few related studies are focused on these problems. Objective: In this article, our motivation is to find out if palindromes have important influences on protein folding rates and what’s the mechanism. Method: In this article, the parameters of the palindromes were defined and calculated, the linear regression analysis between the values of each parameter and the experimental protein folding rates were done. Furthermore, to compare the results of different kinds of proteins, proteins were classified into the two-state proteins and the multi-state proteins. For the two kinds of proteins, the above linear regression analysis were performed respectively. Results : Protein folding rates were negatively correlated to the palindrome frequencies for all proteins. An extremely significant negative linear correlation appeared in the relationship between palindrome densities and protein folding rates. And the repeatedly used bases by different palindromes simultaneously have an important effect on the relationship between palindrome density and protein folding rate. Conclusion: The palindromes have important influences on protein folding rates, and the repeatedly used bases in different palindromes simultaneously play a key role in influencing the protein folding rates.

scholarly journals Effects of bracket design on critical contact angle

2013 ◽  
Vol 83 (5) ◽  
pp. 877-884 ◽  
Author(s):  
Xiaomo Liu ◽  
Peng Ding ◽  
Jiuxiang Lin
Keyword(s):  
Contact Angle ◽  
Stainless Steel ◽  
Linear Regression ◽  
Resistance To Sliding ◽  
The Relationship ◽  
State Resistance ◽  
Critical Contact ◽  
Bracket Design

ABSTRACT Objective: To explore how the position of the bracket slots relative to the archwire influences the friction between them, and how bracket design affects the critical contact angle (θc). Materials and Methods: Two kinds of stainless steel archwires (0.016 and 0.019 × 0.025-inch) were tested against four kinds of brackets (Transmission Straight Archwire bracket, Domestic MBT bracket, Tip-Edge Plus bracket, and BioQuick self-ligation bracket) in the dry state. Resistance to sliding (RS) was measured as an increase in contact angle (θ). The value of θc was calculated by two linear regression lines. Results: Friction remained stable when θ &lt; θc, then increased linearly when θ &gt; θc. The θc values of the Tip-Edge Plus bracket and Transmission Straight Archwire bracket were significantly larger than those for the Domestic MBT bracket and BioQuick self-ligation bracket. Conclusions: The relationship between the archwire and bracket slot significantly affects the resistance to sliding. The “edge-off” structure of the Tip-Edge Plus bracket and Transmission Straight Archwire bracket could help to increase the θc value, and to expand the passive configuration range.

scholarly journals Colonic Volume Changes in Paediatric Constipation Compared to Normal Values Measured Using MRI

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 974
Author(s):  
Hayfa Sharif ◽  
Caroline L. Hoad ◽  
Nichola Abrehart ◽  
Penny A. Gowland ◽  
Robin C. Spiller ◽  
...  
Keyword(s):  
Linear Regression ◽  
Physiological State ◽  
Functional Constipation ◽  
Initial Study ◽  
Healthy Controls ◽  
Volume Changes ◽  
Additional Information ◽  
Symptom Reports ◽  
Magnetic Resonance Imaging Mri ◽  
The Relationship

Background: Functional constipation in children is common. Management of this condition can be challenging and is often based on symptom reports. Increased, objective knowledge of colonic volume changes in constipation compared to health could provide additional information. However, very little data on paediatric colonic volume is available except from methods that are invasive or require unphysiological colonic preparations. Objectives: (1) To measure volumes of the undisturbed colon in children with functional constipation (FC) using magnetic resonance imaging (MRI) and provide initial normal range values for healthy controls, and (2) to investigate possible correlation of colonic volume with whole gut transit time (WGTT). Methods: Total and regional (ascending, transverse, descending, sigmoid, and rectum) colon volumes were measured from MRI images of 35 participants aged 7–18 years (16 with FC and 19 healthy controls), and corrected for body surface area. Linear regression was used to explore the relationship between total colon volume and WGTT. Results: Total colonic volume was significantly higher, with a median (interquartile range) of 309 mL (243–384 mL) for the FC group than for the healthy controls of 227 mL (180–263 mL). The largest increase between patients and controls was in the sigmoid colon–rectum region. In a linear regression model, there was a positive significant correlation between total colonic volume and WGTT (R = 0.56, p = 0.0005). Conclusions: This initial study shows increased volumes of the colon in children with FC, in a physiological state, without use of any bowel preparation. Increased knowledge of colonic morphology may improve understanding of FC in this age group and help to direct treatment.

scholarly journals LOW DOSE CT SCAN FOLLOWING PERIACETABULAR OSTEOTOMY: ASSESSMENT OF REDUCTION AND CORRELATION WITH RADIOGRAPHIC MEASURES

2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0021
Author(s):  
Clarabelle DeVries ◽  
Jeffrey J Nepple ◽  
Lucas Fowler ◽  
Sean Akers ◽  
Gail Pashos ◽  
...  
Keyword(s):  
Femoral Head ◽  
Normative Data ◽  
Low Dose ◽  
Periacetabular Osteotomy ◽  
Femoral Head Coverage ◽  
Edge Angle ◽  
Center Edge ◽  
Two Sectors ◽  
Posterior Sector ◽  
Center Edge Angle

Introduction: Periacetabular osteotomy (PAO) has become a favored treatment for symptomatic acetabular dysplasia worldwide. Nevertheless, the parameters for optimal correction to avoid residual instability or iatrogenic impingement have not been defined. Purpose: The purposes of this study were (1) to assess the ability of PAO to correct femoral head coverage to normal ranges as measured by 3D CT scan and (2) to determine if postoperative radiographic parameters of dysplasia are accurate markers of optimal acetabular correction. Methods: A total of 43 hips (in 38 patients, mean 27.7 years, 88.4% female) were enrolled in this prospective cohort study at minimum 1 year after PAO. Postoperative femoral head coverage was assessed via low-dose CT and compared to normative data of asymptomatic hips from the literature. Anterior (3:00-1:15), lateral (1:00-11:00), and posterior (11:25-9:00) sector coverage was defined by averaging the coverage at 15 minute increments in each zone. Postoperative radiographs were utilized to measure lateral center edge angle (LCEA), anterior wall index (AWI), posterior wall index (PWI), and anterior center edge angle (ACEA). Good correction for each sector was defined as coverage from 1 SD below mean to 2 SD above mean. Results: Postoperatively, the anterior sector was normalized in 84% of hips, lateral sector in 84% of hips, and posterior sector in 86% of hips. Sixty-seven percent of hips were corrected to normative range in all three sectors and 19% were corrected in two sectors (86% in at least two sectors). LCEA and PWI showed the highest correlation with lateral and posterior sector coverage with Pearson’s correlation coefficients of 0.67 and 0.71 (p < 0.001), respectively. Weaker correlations were found between anterior coverage and the AWI and ACEA coverage (-0.16 and 0.15, respectively). Good correction was best correlated with the following target values for acetabular correction: LCEA 28°, AI 1°, AWI 0.37, ACEA 32°, and PWI 1.0. Conclusion: PAO can effectively normalize femoral head coverage compared to normative data. Good correction of each sector coverage ranged from 84-86% of cases. The proposed set of radiographic parameter targets were found to be reliable markers of femoral head coverage.

Underestimation of Dose - Response Relationship with Particular Reference to the Relationship between the Dietary Intake of Mercury and its Concentration in Blood

1988 ◽  
Vol 7 (2) ◽  
pp. 129-132 ◽  
Author(s):  
J.C. Sherlock ◽  
M.J. Quinn
Keyword(s):  
Linear Regression ◽  
Dietary Intake ◽  
Dose Response ◽  
Mercury Concentration ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Blood Mercury ◽  
Relationship Of ◽  
The Relationship ◽  
Blood Mercury Concentration

Wide discrepancies have been observed between controlled and uncontrolled intake studies of the relationship of blood mercury concentration to intake of mercury. The probable reason for the apparent discrepancies is that the within-subject variation of mercury intake in the uncontrolled studies was almost certainly considerably larger than the within-subject variation in blood mercury concentration; in these circumstances, the apparent slope obtained from a linear regression of blood mercury on intake will invariably be much smaller than the true slope. Studies of the exposure or intake of any substance should therefore include a consideration of the likely within-subject variation in the exposure or intake relative to that in the effect.

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