Radial Reference Points for Measuring Palmar Tilt and Ulnar Variance on Lateral Wrist Radiographs

2020 ◽  
Vol 25 (01) ◽  
pp. 95-103
Author(s):  
Atilla Arik ◽  
Seval Tanrikulu ◽  
Taylan Demiray ◽  
Gursel Leblebicioglu
Keyword(s):  
Distal Radius ◽  
Reference Point ◽  
Articular Surface ◽  
Reference Points ◽  
Ulnar Variance ◽  
Thin Wires ◽  
Suitable Reference ◽  
Two Parameters ◽  
Radiographic Landmarks ◽  
Serial Measurements

Background: Palmar tilt and ulnar variance are crucial parameters for evaluating the distal radius. Identifying suitable reference points for these parameters on lateral wrist radiographs remains challenging. The purpose of this study was to establish reference points for measuring palmar tilt and ulnar variance on lateral wrist radiographs and to evaluate the reliability of these two parameters using the newly defined reference points. Methods: The distal articular surfaces of 25 cadaver radii were marked at four different locations using thin wires. These bones were radiographed and constant landmarks were recorded. The reliability of the palmar tilt and ulnar variance measurements was assessed using the new reference points and two serial measurements recorded by three observers on 27 standardized lateral wrist radiographs. Results: The reference points for palmar tilt on lateral radiograph were the dorsal and volar end points of the subchondral line. The subchondral line was connected to two of five metaphyseal cortical lines. The reference point for lateral ulnar variance was easily defined on the midpoint of the proximal aspect of the subchondral line. The corresponding posteroanterior central reference point for ulnar variance was at the ulnar corner of the subchondral line. Inter- and intra-observer reliabilities were overall good for the palmar tilt measurements, and excellent for the ulnar variance measurements. Conclusions: Palmar tilt can be determined accurately with a good understanding of the radiographic landmarks on lateral radiographs, and by addressing the problems caused by ulnar inclination of the articular surface of the distal radius. Lateral wrist radiographs can provide a complete picture of the ulnar border of the radius for measuring ulnar variance.

scholarly journals Three-dimensional evaluations of preoperative planning reproducibility for the osteosynthesis of distal radius fractures

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yuichi Yoshii ◽  
Takeshi Ogawa ◽  
Atsuo Shigi ◽  
Kunihiro Oka ◽  
Tsuyoshi Murase ◽  
...  
Keyword(s):  
Distal Radius ◽  
Reference Point ◽  
Preoperative Planning ◽  
Three Dimensional ◽  
Reference Points ◽  
Distal Radius Fractures ◽  
Radius Fractures ◽  
3D Images ◽  
Radial Inclination ◽  
Preoperative Plan

Abstract Background Three-dimensional preoperative planning was applied for the osteosynthesis of distal radius fractures. The objective of this study was to evaluate the reproducibility of three-dimensional preoperative planning for the osteosynthesis of distal radius fractures with three-dimensional reference points. Methods Sixty-three wrists of 63 distal radius fracture patients who underwent osteosynthesis with three-dimensional preoperative planning were evaluated. After taking preoperative CT scans of the injured wrists, 3D images of the distal radius were created. Fracture reduction, implants choices, and placements simulation were performed based on the 3D images. One month after the surgery, postoperative CT images were taken. The reproducibility was evaluated with preoperative plan and postoperative 3D images. The images were compared with the three-dimensional coordinates of radial styloid process, volar and dorsal edges of sigmoid notch, and the barycentric coordinates of the three reference points. The reproducibility of the preoperative plan was evaluated by the distance of the coordinates between the plan and postoperative images for the reference points. The reproducibility of radial inclination and volar tilt on three-dimensional images were evaluated by intra-class correlation coefficient (ICC). Results The distances between the preoperative plan and the postoperative reduction for each reference point were (1) 2.1±1.3 mm, (2) 1.9±1.2 mm, and (3) 1.9±1.2 mm, respectively. The distance between the preoperative plan and postoperative reduction for the barycentric coordinate was 1.3±0.8 mm. ICCs were 0.54 and 0.54 for the volar tilt and radial inclination, respectively (P<0.01). Conclusions Three-dimensional preoperative planning for the osteosynthesis of distal radius fracture was reproducible with an error of about 2 mm for each reference point and the correlations of reduction shapes were moderate. The analysis method and reference points may be helpful to understand the accuracy of reductions for the three-dimensional preoperative planning in the osteosynthesis of distal radius fractures. Trial registration Registered as NCT02909647 at ClinicalTrials.gov

Ulnar variance in distal radial fractures: assessment and interpretation

2022 ◽  
pp. 175319342110703
Author(s):  
Nick A. Johnson ◽  
Rachel Dias ◽  
Joseph J. Dias
Keyword(s):  
Distal Radius ◽  
Articular Surface ◽  
Ulnar Variance ◽  
The Other ◽  
Initial Assessment ◽  
Distal Radial Fractures ◽  
Distal Ulna ◽  
Level Of Evidence ◽  
Number Of Patients

We explored patterns of shortening of the distal radius and investigated the effect of displacement on ‘ulnar variance’ in 250 patients with distal radial fractures. A small number of patients (5%) had a fracture that resulted in true shortening. Thirty-two per cent had fractures that appeared short, but lateral radiographs revealed that the articular surface was tilted, with either the anterior or dorsal rim of the articular surface being proximal to the distal ulna but the other rim was distal to it. We recommend initial assessment of variance on lateral radiographs. If the anterior and dorsal rims of the distal radial articular surface are proximal to the distal ulna, then true shortening is present and lengthening and stabilization, to hold the radius distracted, should be considered. If only one rim is proximal to the distal ulna, then correction of the tilt will lessen the apparent positive variance. Level of evidence: IV

scholarly journals Computer-Aided Assessment of Displacement and Reduction of Distal Radius Fractures

Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 719
Author(s):  
Yuichi Yoshii ◽  
Yasukazu Totoki ◽  
Atsuo Shigi ◽  
Kunihiro Oka ◽  
Takeshi Ogawa ◽  
...  
Keyword(s):  
Distal Radius ◽  
Reference Point ◽  
Three Dimensional ◽  
Reference Points ◽  
Distal Radius Fractures ◽  
Barycentric Coordinates ◽  
Radius Fractures ◽  
3D Images ◽  
Computer Aided ◽  
Distal Direction

This study aims to investigate displacements and reductions of distal radius fractures using measurement indices based on the computer-aided three-dimensional (3D) radius shape model. Fifty-two distal radius fracture patients who underwent osteosynthesis were evaluated with pre- and post-operative distal radius 3D images. In the 3D images, three reference points, i.e., the radial styloid process (1), sigmoid notch volar, and dorsal edge (2) (3) were marked. The three-dimensional coordinates of each reference point and the barycentric coordinates of the plane connecting the three reference points were evaluated. The distance and direction moved, due to the reductions for each reference point, were (1) 12.1 ± 8.1 mm in the ulnar-palmar-distal direction, (2) 7.5 ± 4.1 mm in the ulnar-palmar-proximal direction, and (3) 8.2 ± 4.7 mm in the ulnar-palmar-distal direction relative to the preoperative position. The barycentric coordinate moved 8.4 ± 5.3 mm in the ulnar-palmar-distal direction compared to the preoperative position. This analyzing method will be helpful to understand the three-dimensional direction and the extent of displacements in distal radius fractures.

Cognitive Reflection Effects on Time Discounting

2018 ◽  
Vol 39 (2) ◽  
pp. 99-106 ◽  
Author(s):  
Michał Białek ◽  
Przemysław Sawicki
Keyword(s):  
Individual Differences ◽  
Individual Difference ◽  
Delay Discounting ◽  
Reference Point ◽  
Reference Points ◽  
Cognitive Reflection Test ◽  
Process Information ◽  
Time Discounting ◽  
Cognitive Reflection ◽  
The Way

Abstract. In this work, we investigated individual differences in cognitive reflection effects on delay discounting – a preference for smaller sooner over larger later payoff. People are claimed to prefer more these alternatives they considered first – so-called reference point – over the alternatives they considered later. Cognitive reflection affects the way individuals process information, with less reflective individuals relying predominantly on the first information they consider, thus, being more susceptible to reference points as compared to more reflective individuals. In Experiment 1, we confirmed that individuals who scored high on the Cognitive Reflection Test discount less strongly than less reflective individuals, but we also show that such individuals are less susceptible to imposed reference points. Experiment 2 replicated these findings additionally providing evidence that cognitive reflection predicts discounting strength and (in)dependency to reference points over and above individual difference in numeracy.

scholarly journals The triangular fibrocartilage complex on high-resolution 3 T MRI in healthy adolescents: the thin line between asymptomatic findings and pathology

2021 ◽  
Author(s):  
Anne-Sophie van der Post ◽  
Sjoerd Jens ◽  
Frank F. Smithuis ◽  
Miryam C. Obdeijn ◽  
Roelof-Jan Oostra ◽  
...  
Keyword(s):  
Signal Intensity ◽  
Sagittal Plane ◽  
Articular Surface ◽  
Triangular Fibrocartilage Complex ◽  
Ulnar Variance ◽  
Observer Agreement ◽  
Mri Findings ◽  
Mri Features ◽  
Triangular Fibrocartilage ◽  
The Individual

Abstract Objective The objective of the study is to provide a reference for morphology, homogeneity, and signal intensity of triangular fibrocartilage complex (TFCC) and TFCC-related MRI features in adolescents. Materials and methods Prospectively collected data on asymptomatic participants aged 12–18 years, between June 2015 and November 2017, were retrospectively analyzed. A radiograph was performed in all participants to determine skeletal age and ulnar variance. A 3-T MRI followed to assess TFCC components and TFCC-related features. A standardized scoring form, based on MRI definitions used in literature on adults, was used for individual assessment of all participants by four observers. Results per item were expressed as frequencies (percentages) of observations by all observers for all participants combined (n = 92). Inter-observer agreement was determined by the unweighted Fleiss’ kappa with 95% confidence intervals (95% CI). Results The cohort consisted of 23 asymptomatic adolescents (12 girls and 11 boys). Median age was 13.5 years (range 12.0–17.0). Median ulnar variance was −0.7 mm (range − 2.7–1.4). Median triangular fibrocartilage (TFC) thickness was 1.4 mm (range 0.1–2.9). Diffuse increased TFC signal intensity not reaching the articular surface was observed in 30 (33%) observations and a vertical linear increased signal intensity with TFC discontinuation in 19 (20%) observations. Discontinuation between the volar radioulnar ligament and the TFC in the sagittal plane was seen in 23 (25%) observations. The extensor carpi ulnaris was completely dislocated in 10 (11%) observations, more frequent in supinated wrists (p = 0.031). Inter-observer agreement ranged from poor to fair for scoring items on the individual TFCC components. Conclusion MRI findings, whether normal variation or asymptomatic abnormality, can be observed in TFCC and TFCC-related features of asymptomatic adolescents. The rather low inter-observer agreement underscores the challenges in interpreting these small structures on MRI. This should be taken into consideration when interpreting clinical MRIs and deciding upon arthroscopy.

Fragment-specific fixation for complex intra-articular fractures of the distal radius: results of a prospective single-centre trial

2012 ◽  
Vol 37 (8) ◽  
pp. 765-771 ◽  
Author(s):  
A. S. Gavaskar ◽  
S. Muthukumar ◽  
N. Chowdary
Keyword(s):  
Distal Radius ◽  
Articular Surface ◽  
Distal Radius Fractures ◽  
First Year ◽  
Functional Evaluation ◽  
Radius Fractures ◽  
Articular Fractures ◽  
Functional Scores ◽  
Radial Length ◽  
Specific Fixation

The goal was to evaluate the efficacy of 2.4 mm column-specific plating for intra-articular distal radius fractures. In total, 105 patients with AO type C distal radius fractures were operated on using the locking distal radius system, Synthes. Follow-up assessments including clinical (wrist and forearm range of motion, grip strength), radiological (articular step, radial length and inclination, volar tilt, and ulnar variance), and functional scores (Disabilities of the Arm, Shoulder, and Hand; Patient Rated Wrist Evaluation) were made at regular intervals until 1 year. Union was obtained in all patients. Articular surface was anatomically reconstructed in 74 patients (70.5%). Clinical and functional evaluation showed significant continuous improvements over the first year. C1 fractures had a better chance of anatomical reduction compared with C2 and C3 fractures. Fracture type, quality of reduction, and presence of degenerative changes did not show a significant effect on functional outcome scores. Column-specific fixation of the distal radius can achieve satisfactory results in complex intra-articular fractures.

scholarly journals ILRS Reference Point Determination Using Close Range Photogrammetry

2021 ◽  
Vol 11 (6) ◽  
pp. 2785
Author(s):  
Michael Lösler ◽  
Cornelia Eschelbach ◽  
Thomas Klügel ◽  
Stefan Riepl
Keyword(s):  
Reference Point ◽  
Reference Points ◽  
Geodetic Reference System ◽  
Unscented Transformation ◽  
Local Ties ◽  
Close Range Photogrammetry ◽  
Crucial Component ◽  
Space Geodetic Techniques ◽  
Close Range ◽  
Point Determination

A global geodetic reference system (GGRS) is realized by physical points on the Earth’s surface and is referred to as a global geodetic reference frame (GGRF). The GGRF is derived by combining several space geodetic techniques, and the reference points of these techniques are the physical points of such a realization. Due to the weak physical connection between the space geodetic techniques, so-called local ties are introduced to the combination procedure. A local tie is the spatial vector defined between the reference points of two space geodetic techniques. It is derivable by local measurements at multitechnique stations, which operate more than one space geodetic technique. Local ties are a crucial component within the intertechnique combination; therefore, erroneous or outdated vectors affect the global results. In order to reach the ambitious accuracy goal of 1 mm for a global position, the global geodetic observing system (GGOS) aims for strategies to improve local ties, and, thus, the reference point determination procedures. In this contribution, close range photogrammetry is applied for the first time to determine the reference point of a laser telescope used for satellite laser ranging (SLR) at Geodetic Observatory Wettzell (GOW). A measurement campaign using various configurations was performed at the Satellite Observing System Wettzell (SOS-W) to evaluate the achievable accuracy and the measurement effort. The bias of the estimates were studied using an unscented transformation. Biases occur if nonlinear functions are replaced and are solved by linear substitute problems. Moreover, the influence of the chosen stochastic model onto the estimates is studied by means of various dispersion matrices of the observations. It is shown that the resulting standard deviations are two to three times overestimated if stochastic dependencies are neglected.

Intra-articular distal radius fractures in elderly patients: a randomized prospective study of casting versus volar plating

2017 ◽  
Vol 43 (2) ◽  
pp. 142-147 ◽  
Author(s):  
Daniel Martinez-Mendez ◽  
Alejandro Lizaur-Utrilla ◽  
Joaquin de-Juan-Herrero
Keyword(s):  
Conservative Treatment ◽  
Elderly Patients ◽  
Distal Radius ◽  
Articular Surface ◽  
Distal Radius Fractures ◽  
Volar Plating ◽  
Radius Fractures ◽  
Level Of Evidence ◽  
Loss Of Reduction

We compared outcomes in elderly patients with intra-articular distal radius fractures treated by closed reduction and plaster immobilization or open reduction and internal fixation with a volar plate. Ninety-seven patients older than 60 years were randomly allocated to conservative (47 patients) or surgical (50 patients) treatment. Over a 2-year period, we assessed patient-rated wrist evaluation score, DASH (disability arm, shoulder and hand) questionnaire, pain, wrist range of motion, grip strength, and radiological parameters. The functional outcomes and quality of life were significantly better after volar plating fixation compared with conservative treatment. We found that restoration of the articular surface, radial inclination, and ulnar variance affected the outcomes, but the articular step-off did not. Twenty-five per cent of the patients with conservative treatment had secondary loss of reduction. We conclude that surgical plating leads to better outcomes than conservative treatment for elderly patients with intra-articular distal radius fractures. Level of evidence: I

An Alternative Perspective on Recruitment Overfishing and Biological Reference Points

1987 ◽  
Vol 44 (4) ◽  
pp. 913-918 ◽  
Author(s):  
M. P. Sissenwine ◽  
J. G. Shepherd
Keyword(s):  
Fisheries Management ◽  
Reference Point ◽  
Reference Points ◽  
Fishing Mortality ◽  
Alternative Perspective ◽  
Conventional Models ◽  
Definition Of ◽  
Yield Per Recruit ◽  
Spawning Biomass

Biological reference points are used to guide fisheries management decisions. The reference points most often used are expressed in terms of fishing mortality rate (F). Fmsy relates to the maximization of sustainable yield. In principle, it is a most useful reference point, but in practice it is difficult to estimate. Fmax and F0.1 relate to certain levels of yield per recruit and are easily estimated, but they ignore conservation of the resource. Recruitment overfishing has usually been understood to occur when a population has been fished down to a point where recruitment is substantially reduced or fails. It has not been used as a basis for a biological reference point because the definition is vague and cannot be readily related to fishing mortality. Levels of spawning biomass below which recruitment seems to be reduced have been used, but their determination from available data is usually difficult and controversial. We propose an alternative definition of recruitment overfishing in terms of the level of fishing pressure that reduces the spawning biomass of a year class over its lifetime below the spawning biomass of its parents on average. Conventional models and types of data can be used to determine this level of F, denoted as Frep, which clearly relates to the replacement of spawning biomass and thus to sustainability of a population and yield in the long term.

scholarly journals Albanian Aorist and Time Reference Points

2020 ◽  
Vol 10 (3) ◽  
pp. 115
Author(s):  
Muhamet Reçica ◽  
Naser Pajaziti
Keyword(s):  
Reference Point ◽  
Reference Points ◽  
The Other ◽  
Temporal Relations ◽  
Time Dimension ◽  
Relative Time ◽  
Absolute Time ◽  
Temporal System ◽  
The Absolute

Topics related to the structure of the temporal system of Albanian language always give opportunities for new discussions to deal with certain aspects related to various forms of this system, and one of them is the aorist, as a tense containing many semantic, temporal, aspectual, stylistic values, etc. The relationships that exist between the verbal tenses in this system within the absolute time-relative time dimension, which relate to the independent or dependent use of temporal forms against one another in different discoursing contexts, make up an interpretation-based approach to interest. Hence, the essential objective of this paper will be specifically the relations of the Albanian aorist to the other verbal forms, always observed with a time reference point, to illuminate the character of these purely temporal relations against each other under all circumstances of the actions that take place and are displayed by verbal forms in different contexts, relying on the corpus of examined materials.

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