EBRA Release 2012 - Einzel-Bild-Röntgen-Analyse

© Unit Geometry and CAD, University of Innsbruck, Austria

University of Innsbruck, Austria / Program by C. Brunhuber, November 2002


 

EBRA is a method for migration measurement of Total Hip Replacements in standard pelvic AP-radiographs. It has been developed cooperatively by members of the Department of Orthopedics and the Department of Mathematics and Geometry at the University ofInnsbruck, Austria, since 1984.

EBRA Release 2012 is the most recent software version for measurement in digital radiographs saved in JPG-, GIF- or BMP- fileformat. It is a standalone VisualBasic program running completely independent from the former used basic image analysis package OPTIMATE.


 

General Instructions

(1) Getting an overview over the radiographic series

Load all images of the series by using the command new Window in the File-Menue. Then display them simultaneously with the command Tile in the WINDOWS-Taskbar (right click). Try to find the clearest pelvic contoures which are visible in all radiographs of the series. Especially sacral foramina at the top of the picture may be cut off !

(2) Choosing the best pelvic reference lines

The basic line of the EBRA-reference-system may be either a line tangent to both foramina obturatoria or to the caudal contoures of the pelvic bone. Chosen once it must remain the same throughout the whole series (This is valid for all reference lines!). The second horizontal line may be tangent to the upper margin of the pubic ramus or to one of the teardrop-figures or - if the first line was chosen at the caudal contour of the pelvic bone - to one of the foramina obturatoria. The third (uppermost) horizontal line may be chosen tangent to one of the sacral foramina. Be careful to identify always the same foramen throughout the whole series!

 cup-lines

(3) Making up the decision on the type of evaluation

If you are in doubt which type of evaluation will be suited for your type of hip socket use the corresponding help text Supported Types of Hip Sockets. The evaluation may be based on either the contour of the spherical head (if it is clearly visible) or on that of the cup. If the rim of the cup is circular ist may be used for calculation of inclination and anteversion of the cup. Once chosen and filled in the data form the type of evaluation must remain the same for the whole series.

(4) Filling in the data form

Do not forget to fill in the correct date of the radiogram! Either the true head-diameter or the true cup size must be known for evaluation. The input of the focus-film-distance is optional. Knowledge and input of the exact focus-film-distance will enhance accurcy.

(5) Enhancing the image

If you want to use one of the Sharpen-options in the Image Tools-Menue you should apply it to all images of the series!


 

Main Menue

cup-main-menu
 

File

Open > open new image file

New Window > open new EBRA for simultaneous display of several images

Patient's Data > input patient's data

Reload Landmarks > reload original landmarks from BIN-file if they have been destroyed

Write Data > save results to data file

Exit > terminates the program

Zoom

Zoom+ > zoom in (= enlargement)

Zoom- > zoom out

Zoom with Mouse > zoom in by mouse click

CenterMode    > mouse position at click will be centered in the zoomed image

Image Tools

adjust Colors > adjustment of brightness and contrast

reset Colors > restores the original grey levels

sharpen > filtering (maybe a little time consuming in large images)

sharpen more > Use always the same sharpen option for all images of the series!

sharpen strong

invert > turns black into white

hardcopy > prints the current image

Measurement Tools

Head > input points of head contour (min = 3 points)

Cup > input points of cup contour (min = 3 points)

Rim > input points of rim or contrast wire (min = 5 points or exactly

3 points including the first 2 on the main axis of the ellipse)

enable Ruler > Optional line determining the angle of cup inclination

enable Cross > Setting of a horizontal and a vertical tangent to the cup contour

(for prostheses of type 9)

Calibrate > Input of 2 points and their known distance

in oder to calculate magnification

calc Distance > Utility for length measurement between 2 points (in calibrated millimeters)

reset Grid > restores the default grid of pelvic reference lines

Menue ?

About > Information on program version

Help > loads this help file

Register > enables setting of License Name and Expiration Date after input of License Key


 

Patient's Data Form

cup-patients-data
 

Use Tab-Key for cursor positioning!

Date > the date of the radiograph in the order year-month-day (yyyymmdd)

Study-ID > an alphanumeric string chracterizing the patient´s membership in a certain study

Evaluation Type > a number from 1 to 9 corresponding with the type of prostheses. The Type 7a

stands for the SL-Cup by PROTEK

Head Diameter > head size in mm

Cup Diameter > cup size in mm

Focus Dist > optional input of radiographic focus distance (in mm) if known

Datafile > name of patient´s datafile without extension .DAT (it will be appended automatically)



Supported Types of Hip Sockets

These are the types of hip sockets supported by the EBRA-DIGITAL measurement software. For more information click on the corresponding icon.

cup-type1

Type 1

Polyäthylen Cups with circular contrast wire as designed for instance by Robert Mathys (RM-Cup) or Müller.

The fotogrammetric reconstruction of the radiograph is based on the head contour, which requires a minimum of 4 points for input. The cup represented by the elliptic image of the contrst wire could be evaluated by 3 points (1.vertex + 2.vertex + arbitrary point) or by a minimum of 5 points evenly distributed on the contour.

Available parameters: head migration, cup migration, inclination and anteversion of the cup, wear

cup-type2

Type 2

Polyäthylen Cups with circular contrast wire as designed for instance by Robert Mathys (RM-Cup) or Müller.

The fotogrammetric reconstruction of the radiograph is based on the head contour, which requires a minimum of 4 points for input. The cup represented by the elliptic image of the contrst wire could be evaluated by 3 points (1.vertex + 2.vertex + arbitrary point) or by a minimum of 5 points evenly distributed on the contour.

Available parameters: head migration, cup migration, inclination and anteversion of the cup, wear

cup-type3 Type 3

Polyäthylen Cups with circular contrast wire as designed for instance by Charnley.

The fotogrammetric reconstruction of the radiograph is based on the head contour, which requires a minimum of 4 points for input. The cup represented by the elliptic image of the contrst wire could be evaluated by a minimum of 5 points evenly distributed on the contour.

Available parameters: head migration, cup migration, inclination of the cup, wear

cup-type4

Type 4

Conical Titanium Cup with circular rim as designed for instance by Zweymüller.

The fotogrammetric reconstruction of the radiograph is based on the head contour, which requires a minimum of 4 points for input. The cup represented by the elliptic image of its rim could be evaluated by 3 points (1.vertex + 2.vertex + arbitrary point) or by a minimum of 5 points evenly distributed on the contour.

Available parameters: head migration, cup migration, inclination and anteversion of the cup, wear

cup-type5

Type 5

Conical Titanium Cup with circular rim as designed for instance by Zweymüller.

The fotogrammetric reconstruction of the radiograph is based on the head contour, which requires a minimum of 4 points for input. The cup represented by the elliptic image of its rim could be evaluated by 3 points (1.vertex + 2.vertex + arbitrary point) or by a minimum of 5 points evenly distributed on the contour.

Available parameters: head migration, cup migration, inclination and anteversion of the cup, wear

cup-type6

Type 6

Porous Coated Anatomic (PCA) Cup.

The fotogrammetric reconstruction of the radiograph is based on the cup contour which requires a minimum of 4 points for input. The head could be evaluated by a minimum of 4 points distributed on the medial and lateral side of ist contour.

Available parameters: head migration, cup migration, inclination of the cup, wear

cup-type7

Type 7 

Spherical metal backed cups as for instance designed by Harris/Galante.

The fotogrammetric reconstruction of the radiograph is based on the cup contour which requires a minimum of 4 points for input. The head could be evaluated by a minimum of 4 points distributed on the medial and lateral side of ist contour. Additionally the rim of the cup could be evaluated by 3 points (1.vertex + 2.vertex + arbitrary point) or a minimum of 5 evenly distributed arbitrary points of ist elliptic contour.

Available parameters: head migration, cup migration, inclination and anteversion of the cup, wear 

 

Type 7a

SL-CUP designed by PROTEK, Switzerland. Special spherical metal backed cup - Input similar to Type 7

Available parameters: head migration, cup migration, inclination of the cup, wear - No anteversion!

cup-type8

Type 8

Spherical metal backed cups as for instance designed by Harris/Galante.

The fotogrammetric reconstruction of the radiograph is based on the cup contour which requires a minimum of 4 points for input. The head could be evaluated by a minimum of 4 points distributed on the medial and lateral side of ist contour. Additionally the rim of the cup could be evaluated by 3 points (1.vertex + 2.vertex + arbitrary point) or a minimum of 5 evenly distributed arbitrary points of ist elliptic contour.

Available parameters: head migration, cup migration, inclination and anteversion of the cup, wear

cup-type9

Type 9

Non-spherical metal cup as for instance designed by Hofer.

The fotogrammetric reconstruction of the radiograph is based on the head contour, which requires a minimum of 4 points for input. The cup is evaluated by the intersection point of two lines tangent to ist contour.

Available parameters: head migration, cup migration, wear

 
 
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