scholarly journals Characterization of version in the dysplastic hip and the need for subsequent femoral derotational osteotomy after periacetabular osteotomy

2020 ◽  
Author(s):  
Andrea M Spiker ◽  
Kara G Fields ◽  
Joseph T Nguyen ◽  
Alexandra C Wong ◽  
Ernest L Sink
Keyword(s):  
Hip Dysplasia ◽  
Periacetabular Osteotomy ◽  
Three Dimensional ◽  
Center Edge ◽  
Derotational Osteotomy ◽  
Patient Reported ◽  
Relationship Of ◽  
The Relationship ◽  
Lateral Center Edge Angle

Abstract Hip dysplasia is a three-dimensional pathomechanical condition that is often more complex than the standard method of measuring lateral center edge angle (CEA) can quantify. Yet there is a paucity of literature examining the differences in version seen between dysplastic and non-dysplastic femoroacetabular impingement (FAI) hips, the relationship of acetabular and femoral version (FV) within dysplastic hips and the contribution of each of these factors to symptoms and outcomes of dysplasia treatment. We sought to describe the acetabular version (AcetV) and FV in dysplastic hips and quantify how these measurements compared with non-dysplastic FAI hips. We also sought to analyze the association of these factors with patient-reported outcomes (PROs) after periacetabular osteotomy (PAO) and determine the need for subsequent femoral derotational osteotomy after PAO. A total of 113 dysplastic patients who underwent PAO (92% female, mean age 24) were compared with 1332 (45% female, mean age 25) non-dysplastic FAI (CEA > 25°) patients. We found that dysplastic hips had a statistically higher AcetV and FV than non-dysplastic FAI hips. There was a very weak correlation between AcetV and FV in dysplastic hips, suggesting that patients with higher AcetV did not necessarily have higher FV. There was no association with AcetV or FV and patient outcomes in our very limited analysis of PROs after PAO, and only 5% of patients with excessive FV (>20°) required subsequent femoral derotational osteotomy, suggesting that in a majority of patients with hip dysplasia, FV may not impact the post-operative clinical course.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

scholarly journals BORDERLINE ACETABULAR DYSPLASIA: THREE-DIMENSIONAL DEFORMITY PREDICTORS OF THE DIAGNOSIS OF SYMPTOMATIC INSTABILITY TREATED WITH PERIACETABULAR OSTEOTOMY

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0016
Author(s):  
Elizabeth Graesser ◽  
Maria Schwabe ◽  
Cecilia Pascual Garrido ◽  
John C. Clohisy ◽  
Jeffrey J. Nepple
Keyword(s):  
Low Dose ◽  
Acetabular Dysplasia ◽  
Periacetabular Osteotomy ◽  
Alpha Angle ◽  
Three Dimensional ◽  
Acetabular Coverage ◽  
Low Dose Ct ◽  
Femoral Version ◽  
Center Edge ◽  
Hip Morphology

Introduction: Borderline acetabular dysplasia is classically defined as a lateral center edge angle (LCEA) of 20-25 degrees. The optimal treatment strategy in this patient group remains controversial, with some patients having primarily hip instability-based symptoms, while others have primarily impingement-based symptoms (non-instability). The purpose of the current study was to define the 3D characteristics on low-dose CT that differentiate patients with instability symptoms from those without instability in the setting of borderline acetabular dysplasia. Methods: Seventy consecutive hips with borderline acetabular dysplasia undergoing surgical treatment were included in the current study. All patients underwent low-dose pelvic CT with femoral version assessment for preoperative planning. CT measurements included alpha angle and radial acetabular coverage (RAC) at standardized clockface positions (9:00-posterior to 3:00-anterior), central and cranial acetabular version. RAC was assessed in three sectors (anterior, superior, and posterior) and defined (relative to published normative data) as normal (-1 SD, +1 SD), undercoverage (<-1 SD), or overcoverage (>+1 SD). Statistical analysis was performed to compare the CT characteristics of the symptomatic instability and non-instability groups. Results: Of the 70 hips, 62.9% had the diagnosis of symptomatic instability, while 37.1% had no instability symptoms. Hips with instability (compared to non-instability) had significantly lower alpha angle (maximal difference at 1:00 - 47.0° vs. 59.4°), increased femoral version (22.3° vs. 15.3°), and decreased radial acetabular coverage (maximal difference at 1:00 – 59.9% vs. 62.2%) (all p<0.001). Multivariate analysis identified femoral version (OR 1.1, p=0.02), alpha angle at 1:00 (OR 0.91, p=0.02), and RAC at 1:00 (OR 0.46, p=0.003) as independent predictors of the presence of instability. The model combining these three factors had excellent predictive probability with a c-statistic 0.92. Conclusion: We found significant differences in the 3D hip morphology of the symptomatic instability and non-instability subgroups within the borderline dysplasia cohort. In the setting of borderline dysplasia, three-dimensional deformity characterization with low-dose CT allowed for differentiation of patients diagnosed with underlying instability vs. non-instability. Femoral version, alpha angle at 1:00, and radial acetabular coverage at 1:00 were identified as independent predictors of diagnosis in borderline acetabular dysplasia. Summary: This study attempts to define 3D CT characteristics to help distinguish between patients with impingement-based vs instability-based symptoms of borderline acetabular dysplasia.

A Research on the Morphology and Composition of Flocs (Part 1: Floc Breaage Disregarded)

2013 ◽  
Vol 726-731 ◽  
pp. 1566-1572 ◽  
Author(s):  
Shi Qiang Ding ◽  
Qing Na Li ◽  
Xin Rong Pang ◽  
Ji Run Xu
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
New Classification ◽  
Suspension Viscosity ◽  
Primary Particles ◽  
Long Time ◽  
Relationship Of ◽  
The Relationship ◽  
Three Dimensional Space ◽  
Floc Breakage

The characteristics of flocs aggregated in flocculation have been paid more and more attention for a long time. In this paper, a new classification and analyses method dealing with the flocs is developed. The flocs formed after flocculation is divided into four kinds, including the left primary particles, linear flocs with all component particles in a line, planar flocs with all component particles on a plane and volumetric flocs with all component particles in a three-dimensional space. By analyzing the formation approaches of different kind of flocs regardless of the floc breakage, the number of every kind of floc is analyzed to be related with the suspension concentration mathematically. After comparing the different items in the models describing the relationship of floc number and concentration, a series of simplified expressions are presented. Lastly, a mathematical equation relating the measurable suspension viscosity with the numbers of different flocs is obtained.

scholarly journals Heart Rate Dependency and Inter-Lead Variability of the T Peak – T End Intervals

2020 ◽  
Vol 11 ◽  
Author(s):  
Irena Andršová ◽  
Katerina Hnatkova ◽  
Martina Šišáková ◽  
Ondřej Toman ◽  
Peter Smetana ◽  
...  
Keyword(s):  
Heart Rate ◽  
Three Dimensional ◽  
Rate Dependency ◽  
Rate Dependent ◽  
Heart Rate Correction ◽  
Ecg Leads ◽  
Relationship Of ◽  
The Relationship ◽  
Vector Magnitude

The electrocardiographic (ECG) assessment of the T peak–T end (Tpe) intervals has been used in many clinical studies, but several related physiological aspects have not been reported. Specifically, the sources of the Tpe differences between different ECG leads have not been systematically researched, the relationship of Tpe duration to underlying heart rate has not been firmly established, and little is known about the mutual correspondence of Tpe intervals measured in different ECG leads. This study evaluated 796,620 10-s 12-lead ECGs obtained from long-term Holters recorded in 639 healthy subjects (311 female) aged 33.8 ± 9.4 years. For each ECG, transformation to orthogonal XYZ lead was used to measure Tpe in the orthogonal vector magnitude (used as a reference for lead-to-lead comparisons) and to construct a three-dimensional T wave loop. The loop roundness was expressed by a ratio between its circumference and length. These ratios were significantly related to the standard deviation of Tpe durations in different ECG leads. At the underlying heart rate of 60 beats per minute, Tpe intervals were shorter in female than in male individuals (82.5 ± 5.6 vs 90.0 ± 6.5 ms, p &lt; 0.0001). When studying linear slopes between Tpe intervals measured in different leads and the underlying heart rate, we found only minimal heart rate dependency, which was not systematic across the ECG leads and/or across the population. For any ECG lead, positive Tpe/RR slope was found in some subjects (e.g., 79 and 25% of subjects for V2 and V4 measurements, respectively) and a negative Tpe/RR slope in other subjects (e.g., 40 and 65% for V6 and V5, respectively). The steepest positive and negative Tpe/RR slopes were found for measurements in lead V2 and V4, respectively. In all leads, the Tpe/RR slope values were close to zero, indicating, on average, Tpe changes well below 2 ms for RR interval changes of 100 ms. On average, longest Tpe intervals were measured in lead V2, the shortest in lead III. The study concludes that the Tpe intervals measured in different leads cannot be combined. Irrespective of the measured ECG lead, the Tpe interval is not systematically heart rate dependent, and no heart rate correction should be used in clinical Tpe investigations.

scholarly journals A Voice Unknown: Undercurrents in Mussorgsky's Sunless

2004 ◽  
Vol 28 (1) ◽  
pp. 15-49
Author(s):  
Simon Perry
Keyword(s):  
Effective Means ◽  
Pitch Organization ◽  
Affective Meaning ◽  
Significant Achievement ◽  
Critical Interpretation ◽  
Relationship Of ◽  
The Relationship ◽  
Artistic Self ◽  
Point Of Departure

Mussorgsky's Sunless cycle is aesthetically and stylistically an anomalous member of his oeuvre. Its notably effaced, pared-down, and withdrawn qualities present challenges to critical interpretation. Its uniqueness, however, renders it a crucial work for furnishing the fullest possible picture of Mussorgsky as a creative artist. The author of its texts, Golenishchev-Kutuzov (whose relationship with Mussorgsky at the time of its writing possibly extended beyond the platonic) has been identified by recent scholarship as an essential "eye-witness" for those to whom Stasov's populist characterization of the composer does not ring entirely true. Golenishchev-Kutuzov believed that in Sunless Mussorgsky first revealed his authentic artistic self. According to Golenishchev-Kutuvoz, Mussorgsky regarded his signal achievement in Sunless to have been the eradication of all elements other than "feeling." In other words, he had thrown off the stylistic shackles imposed by the aesthetics of realism and relied entirely on intuitive harmonic invention as the sole conveyor of a purely subjective, "affective" meaning in the cycle. This hypothesis forms the point of departure for an investigation of select numbers of the cycle. Analysis reveals that the affective aspect is not the only significant element operative. Alongside remnants of the realist style, there is evidence, of varying degrees of subtlety, for a knowing use of symmetrical pitch organization. Mussorgsky not only adapted the usual referential attachments of symmetrically based chromaticism--typically found in Russian operas of the second half of the nineteenth century--he also, through extremely simple but effective means, synthesized the "intuitive" harmonic and "rational" symmetrical elements of the cycle's pitch organization so that the latter emerges seamlessly out of the former. This remarkable synthesis ensures the cycle's uniformity of tone while also allowing for a reading that extends beyond the generally affective to the symbolically more specific. This symbolic level of reading offers several interpretative possibilities, one of which may refer even to the relationship of the poet and the composer. Irrespective of such potentials for interpretation, the most significant achievement in the cycle remains the synthesis of the intuitive/affective and rational/symbolic elements of its organization. Songs 1, 2, 3, and 6 of the cycle are considered in detail.

Aerodynamic Characteristics Analysis of High-Speed Train on Cutting under Crosswinds

2013 ◽  
Vol 300-301 ◽  
pp. 62-67
Author(s):  
Kun Ye ◽  
Ren Xian Li
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
High Speed Train ◽  
Aerodynamic Forces ◽  
Cutting Depth ◽  
Cutting Slope ◽  
Characteristics Analysis ◽  
Relationship Of ◽  
The Relationship

Cutting is an effective device to reduce crosswind loads acting on trains. The cutting depth, width and gradient of slope are important factors for design and construction of cutting. Based on numerical analysis methods of three-dimensional viscous incompressible aerodynamics equations, aerodynamic side forces and yawing moments acting on the high-speed train, with different depths and widths of cutting，are calculated and analyzed under crosswinds，meanwhile the relationship of the gradient of cutting slope and transverse aerodynamic forces acting on trains are also studied. Simulation results show that aerodynamic side forces and yawing moments acting on the train（the first, middle and rear train）decrease with the increase of cutting depth. The relationship between transverse forces (moments) coefficients acting on the three sections and the cutting depth basically is the three cubed relation. The bigger is cutting width，the worse is running stability of train. The relationship between yawing moments coefficients acting each body of the train and the cutting width approximately is the three cubed relation. The transverse Aerodynamic forces decreased gradually with the increase of the gradient of cutting slope, the relationship between yawing moments coefficients acting each body of the train and the gradient of cutting slope basically is the four cubed relation.

Postoperative excessive anterior acetabular coverage is associated with decrease in range of motion after periacetabular osteotomy

2020 ◽  
pp. 112070002091037 ◽  
Author(s):  
Shinya Hayashi ◽  
Shingo Hashimoto ◽  
Tomoyuki Matsumoto ◽  
Koji Takayama ◽  
Nao Shibanuma ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Clinical Outcomes ◽  
Internal Rotation ◽  
Hip Dysplasia ◽  
External Rotation ◽  
Periacetabular Osteotomy ◽  
Femoral Anteversion ◽  
Acetabular Coverage ◽  
3 Dimensional ◽  
The Relationship

Purpose: The aim of this study was to evaluate the relationship between acetabular 3-dimensional (3D) alignment reorientation and clinical range of motion (ROM) after periacetabular osteotomy (PAO). Methods: 50 patients (58 hips) with hip dysplasia participated in the study and underwent curved PAO. The pre- and postoperative 3D centre-edge (CE) angles and femoral anteversion were measured and compared with clinical outcomes, including postoperative ROM. Results: The correlation between pre- and postoperative acetabular coverage and postoperative ROM was evaluated. Postoperative abduction and internal rotation ROM were significantly associated with postoperative lateral CE angles (abduction; p < 0.001, internal rotation; p = 0.028); flexion and internal rotation ROM was significantly associated with postoperative anterior CE angles (flexion; p < 0.001, internal rotation; p = 0.028). Femoral anteversion was negatively correlated with postoperative abduction ( p = 0.017) and external rotation ( p = 0.047) ROM. Conclusion: Postoperative anterior acetabular coverage may affect internal rotation ROM more than the lateral coverage. Therefore, the direction of acetabular reorientation should be carefully determined according to 3D alignment during PAO.

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