scholarly journals The Watershed Line of the Distal Radius: Cadaveric and Imaging Study of Anatomical Landmarks

2019 ◽  
Vol 09 (01) ◽  
pp. 044-051
Author(s):  
Minke Bergsma ◽  
Job N. Doornberg ◽  
Annelise Borghorst ◽  
W.A. Kernkamp ◽  
R. L. Jaarsma ◽  
...  
Keyword(s):  
Distal Radius ◽  
Surgical Approach ◽  
Intraoperative Imaging ◽  
Three Dimensional ◽  
Imaging Study ◽  
Anatomical Landmarks ◽  
Pronator Quadratus ◽  
Volar Approach ◽  
Wide Variability ◽  
Distinct Line

Abstract Background Placement of volar plates remains a challenge as the watershed line may not be an easy-identifiable distinct line intraoperatively. Objectives The main objective of this article is to define how anatomical landmarks identifiable upon the volar surgical approach to the distal radius relate to the watershed line. Methods We identified anatomical landmarks macroscopically upon standard volar approach to the distal radius in 10 cadaveric forearms and marked these with radiostereometric analysis (RSA) beads in cadaveric wrists. The RSA beads were then referenced against the volar osseous structures using quantification of three-dimensional computed tomography and advanced imaging software. Results The mean measurements were the radial and ulnar prominences 11.1 mm and 2.1 mm proximal to the joint line of the distal radius, respectively. The interfossa sulcus was 0.3 mm proximal and 3 mm dorsal to the ulnar prominence. The watershed line was between 3.5 (minimal) and 7.6 (maximal) mm distal to the distal line of insertion of the pronator quadratus. Conclusion The watershed line is situated distal to the pronator quadratus, but with a wide variability making it an impractical landmark for plate position. The osseous ulnar prominence is a good anatomical reference for safe plate positioning, as it is located on the watershed line and easily palpated at surgery. One should keep in mind the sulcus—the point on the watershed line where the flexor pollicis longus runs—can be situated just proximal to the ulnar prominence. Clinical Relevance To provide anatomical landmarks that are easy to identify upon surgical approach without the direct need for intraoperative imaging.

In Vivo changes in the lengths of carpal ligaments after mild dorsal angulation of distal radius fractures

2013 ◽  
Vol 40 (5) ◽  
pp. 494-501 ◽  
Author(s):  
Y. R. Chen ◽  
R. G. Xie ◽  
J. B. Tang
Keyword(s):  
Distal Radius ◽  
Three Dimensional ◽  
Distal Radial Fracture ◽  
Anatomical Landmarks ◽  
Mild Degree ◽  
Uninjured Side ◽  
Computed Tomography Scans ◽  
Dorsal Angulation ◽  
Carpal Ligaments

The need for surgical correction in patients with malunion with mild dorsal angulation after a distal radius fracture is controversial. We specifically investigated in vivo changes in the lengths of carpal ligaments in a group of patients with mild-degree dorsal angulation following a distal radial fracture. We obtained computed tomography scans of both wrists in eight patients, whose distal radius on one side had united with dorsal angulation from 10° to 20°. The three-dimensional images of the carpus were reconstructed and the lengths of wrist ligaments were measured based on known anatomical landmarks. Compared with the contralateral uninjured side, the dorsal radiocarpal ligament and ulnotriquetral ligament were substantially lengthened ( p < 0.05) and the long radiolunate ligament was substantially shortened ( p < 0.05) at most wrist positions except extension. However, five other ligaments that we measured did not show significant differences in length compared with those of the uninjured side ( p > 0.05). The lengths of some ligaments are substantially altered even by mild dorsal angulation of the distal radius, while the lengths of most other ligaments are not substantially affected.

scholarly journals 3D virtual pre-operative planning may reduce the incidence of dorsal screw penetration in volar plating of intra-articular distal radius fractures

2021 ◽  
Author(s):  
Jasper Prijs ◽  
Bram Schoolmeesters ◽  
Denise Eygendaal ◽  
Jean-Paul P. M. de Vries ◽  
Paul C. Jutte ◽  
...  
Keyword(s):  
Diagnostic Imaging ◽  
Distal Radius ◽  
Three Dimensional ◽  
Imaging Study ◽  
Distal Radius Fractures ◽  
Volar Plating ◽  
Radius Fractures ◽  
Operative Planning ◽  
Screw Penetration ◽  
Diagnostic Imaging Study

Abstract Purpose To evaluate the effect of three-dimensional virtual pre-operative planning (3DVP) on the incidence of dorsal screw penetration after volar plating of distal radius fractures. Methods A cross-sectional diagnostic imaging study was performed. Twenty out of 50 patients were randomly selected from our index prospective cohort (IPC): a prior study evaluating dorsal tangential views (DTVs) in reducing dorsal screw penetration in internal fixation of intra-articular distal radius fractures using post-operative CT scans to quantify screw protrusion. Pre-operative CTs from this cohort were now used for 3DVP by three experienced orthopaedic trauma surgeons (supplementary video). 3DVP was compared with the corresponding post-operative CT for assessing screw lengths and incidence of dorsal penetration. The Wilcoxon Signed Ranks test was used to compare screw lengths and the Fishers’ exact for incidence of penetration. Results Three surgeons performed 3DVP for 20 distal radius fractures and virtually applied 60 volar plates and 273 screws. Median screw length was shorter in the 3DVP when compared to IPC: 18 mm (range, 12–22) versus 20 mm (range, 14–26) (p < 0.001). The number of penetrating screws was 5% (13/273 screws) in the 3DVP group compared to 11% (10/91 screws) in the IPC (p = 0.047). Corresponding to a reduction in incidence of at least one dorsally penetrating screw in 40% of patients in the IPC group, to 18% in the 3DVP group (p = 0.069). Conclusion Three-Dimensional Virtual Pre-Operative Planning (3DVP) may reduce the incidence of dorsally penetrating screws in patients treated with volar plating for intra-articular distal radius fractures. Level of evidence II, diagnostic imaging study.

scholarly journals Is Pronator Quadratus Affected In Volar Approach To Distal Radius Fractures?

2020 ◽  
pp. 1
Author(s):  
mahmut tunçez ◽  
hüseyin ursavaş ◽  
hülya tunçez ◽  
mesut tahta
Keyword(s):  
Distal Radius ◽  
Distal Radius Fractures ◽  
Radius Fractures ◽  
Pronator Quadratus ◽  
Volar Approach

Should We Repair the Pronator Quadratus in a Distal Radius Fracture with an Ulnar Styloid Base Fracture? A Biomechanical Study

2021 ◽  
Author(s):  
Mauro Maniglio ◽  
Victor Truong ◽  
Matthias Zumstein ◽  
Lilianna Bolliger ◽  
Michelle H. McGarry ◽  
...  
Keyword(s):  
Distal Radius ◽  
Distal Radioulnar Joint ◽  
Biomechanical Study ◽  
Forearm Rotation ◽  
Ulnar Styloid ◽  
Pronator Quadratus ◽  
Volar Approach ◽  
Druj Instability ◽  
Cadaveric Model

Abstract Background Merits of repairing the pronator quadratus (PQ) to restore distal radioulnar joint (DRUJ) stability after a volar approach remain controversial. Distal radius fractures are often associated with ulnar styloid fractures (USF). When involving the fovea, this USF can lead to a DRUJ instability. The PQ repair may be key in reducing this DRUJ instability. Methods This study aims to assess the biomechanical role of PQ repair in a cadaveric model of USF. In 17 forearm specimens, a USF including the fovea was executed. Positional changes of the DRUJ in forearm rotation and dorso-palmar (DP) translation were measured with variable loads (0, 2.5, and 5N) applied to the PQ origin. Results Forearm rotation and DP-translation decreased significantly with PQ loading of 5N, changing on average by 5 degrees and 0.6 mm, respectively. Conclusion We found a significant decrease in forearm rotation and DP-translation comparing a fully loaded PQ to an unloaded PQ in our cadaveric model.

Three-Dimensional Versus Radiographic Measurements for Analyzing Extra-Articular Distal Radius Malunion

2020 ◽  
Vol 45 (10) ◽  
pp. 984.e1-984.e7
Author(s):  
Lionel Athlani ◽  
Audrey Chenel ◽  
Philippe Berton ◽  
Romain Detammaecker ◽  
Gilles Dautel
Keyword(s):  
Distal Radius ◽  
Three Dimensional ◽  
Radiographic Measurements ◽  
Distal Radius Malunion ◽  
Radius Malunion

scholarly journals Second sacral sacralalar‐iliac (S2AI) screw placement in adult degenerative scoliosis (ADS) patients: an imaging study

BMC Surgery ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Bing Wu ◽  
Kai Song ◽  
Junyao Cheng ◽  
Pengfei Chi ◽  
Zhaohan Wang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Imaging Study ◽  
Outer Diameter ◽  
Degenerative Scoliosis ◽  
Female Patients ◽  
Lateral Angle ◽  
Adult Degenerative Scoliosis ◽  
Imaging Characteristics ◽  
Starting Point ◽  
Trajectory Length

Abstract Background The imaging characteristics of sacral sacralalar-iliac (S2AI) screw trajectory in adult degenerative scoliosis (ADS) patients will be determined. Methods S2AI screw trajectories were mapped on three-dimensional computed tomography (3DCT) reconstructions of 40 ADS patients. The starting point, placement plane, screw template, and a circle centered at the lowest point of the ilium inner cortex were set on these images. A tangent line from the starting point to the outer diameter of the circle was selected as the axis of the screw trajectory. The related parameters in different populations were analyzed and compared. Results The trajectory length of S2AI screws in ADS patients was 12.00 ± 0.99 cm, the lateral angle was 41.24 ± 3.92°, the caudal angle was 27.73 ± 6.45°, the distance from the axis of the screw trajectory to the iliosciatic notch was 1.05 ± 0.81 cm, the distance from the axis of the screw trajectory to the upper edge of the acetabulum was 1.85 ± 0.33 cm, and the iliac width was 2.12 ± 1.65 cm. Compared with females, the lateral angle of male ADS patients was decreased, but the trajectory length was increased (P < 0.05). Compared to patients without ADS in previous studies, the lateral angle of male patients was larger, the lateral angle of female patients was increased, and the caudal angle was decreased (P < 0.05). Conclusions There is an ideal trajectory of S2AI screws in ADS patients. A different direction should be noticed in the placement of S2AI screws, especially in female patients.

Three-dimensional ion imaging study of PCl3 photodissociation at 235 nm

2020 ◽  
Author(s):  
A.I. Chichinin ◽  
C. Maul ◽  
K.-H. Gericke
Keyword(s):  
Three Dimensional ◽  
Imaging Study ◽  
Ion Imaging

scholarly journals Automatic 3D dense phenotyping provides reliable and accurate shape quantification of the human mandible

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pieter-Jan Verhelst ◽  
H. Matthews ◽  
L. Verstraete ◽  
F. Van der Cruyssen ◽  
D. Mulier ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Intraclass Correlation ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Surface Registration ◽  
Anatomical Landmarks ◽  
Centroid Size ◽  
Intraclass Correlation Coefficients ◽  
Total Variability ◽  
Automatic Phenotyping

AbstractAutomatic craniomaxillofacial (CMF) three dimensional (3D) dense phenotyping promises quantification of the complete CMF shape compared to the limiting use of sparse landmarks in classical phenotyping. This study assesses the accuracy and reliability of this new approach on the human mandible. Classic and automatic phenotyping techniques were applied on 30 unaltered and 20 operated human mandibles. Seven observers indicated 26 anatomical landmarks on each mandible three times. All mandibles were subjected to three rounds of automatic phenotyping using Meshmonk. The toolbox performed non-rigid surface registration of a template mandibular mesh consisting of 17,415 quasi landmarks on each target mandible and the quasi landmarks corresponding to the 26 anatomical locations of interest were identified. Repeated-measures reliability was assessed using root mean square (RMS) distances of repeated landmark indications to their centroid. Automatic phenotyping showed very low RMS distances confirming excellent repeated-measures reliability. The average Euclidean distance between manual and corresponding automatic landmarks was 1.40 mm for the unaltered and 1.76 mm for the operated sample. Centroid sizes from the automatic and manual shape configurations were highly similar with intraclass correlation coefficients (ICC) of > 0.99. Reproducibility coefficients for centroid size were < 2 mm, accounting for < 1% of the total variability of the centroid size of the mandibles in this sample. ICC’s for the multivariate set of 325 interlandmark distances were all > 0.90 indicating again high similarity between shapes quantified by classic or automatic phenotyping. Combined, these findings established high accuracy and repeated-measures reliability of the automatic approach. 3D dense CMF phenotyping of the human mandible using the Meshmonk toolbox introduces a novel improvement in quantifying CMF shape.

Preoperative Use of CT Angiography in Infants With Coarctation of the Aorta

2017 ◽  
Vol 8 (2) ◽  
pp. 196-202 ◽  
Author(s):  
Kirsten Rose-Felker ◽  
Joshua D. Robinson ◽  
Carl L. Backer ◽  
Cynthia K. Rigsby ◽  
Osama M. Eltayeb ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Surgical Approach ◽  
New Technology ◽  
Three Dimensional ◽  
Coarctation Of The Aorta ◽  
Computed Tomographic Angiography ◽  
Great Vessel ◽  
Z Score ◽  
Computed Tomographic ◽  
Tomographic Angiography

Background: Computed tomographic angiography (CTA) and echocardiography (echo) are used preoperatively in coarctation of the aorta to define arch hypoplasia and great vessel branching. We sought to determine differences in quantitative measurements, as well as surgical utility, between modalities. Methods: Infants (less than six months) with both CTA and echo prior to coarctation repair from 2004 to 2013 were included. Measurements were compared and correlated with surgical approach. Three surgeons reviewed de-identified images to predict approach and characterize utility. Computed tomographic angiography radiation dose was calculated. Results: Thirty-three patients were included. No differences existed in arch measurements between echo and CTA ( z-score: −2.59 vs −2.43; P = .47). No differences between modalities were seen for thoracotomy ( z-score: −2.48 [echo] vs −2.31 [CTA]; P = .48) or sternotomy ( z-score: −3.13 [echo] vs −3.08 [CTA]; P = .84). Computed tomographic angiography delineated great vessel branching pattern in two patients with equivocal echo findings ( P = .60). Surgeons rated CTA as far more useful than echo in understanding arch hypoplasia and great vessel branching in cases where CTA was done to resolve anatomical questions that remain after echo evaluation. Two of three surgeons were more likely to choose the surgical approach taken based on CTA (surgeon A, P = .02; surgeon B, P = .01). Radiation dose averaged 2.5 (1.6) mSv and trended down from 2.9 mSv (1.8 mSv; n = 20) to 1.6 mSv (0.5 mSv; n = 7) ( P = .06) with new technology. Conclusion: Although CTA and echo measurements of the aorta do not differ, CTA better delineates branching and surgeons strongly prefer it for three-dimensional arch anatomy. We recommend CTA for patients with anomalous arch branching patterns, diffuse or complex hypoplasia, or unusual arch morphology not fully elucidated by echo.

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