Deformity Parameters

Here the bone deformity parameters are recorded. They are measured on the frontal and lateral x-rays by overlaying them with printouts of the matching views generated on the previous page. These parameters allow a deformity correction schedule to be generated.

In the matching views, the blue circles show the x-ray nearest points, and the red circle the target point which is also the origin of the 2D coordinate grid. The grid is behind the frame, in the plane of the x-ray film; the grid spacing is 20mm in each direction. Align the printed and xray images, and use the grid to capture the bone reference coordinates identified on the x-rays. Enter the coordinates below. The x axis is across the A3 page, the z axis up it. The y axis is the line between x-ray source and target point.

If you enter a frame identifier for which you have previously defined deformity parameters, and leave the data fields empty, then the saved data will used and can be edited if required. Enter example-frame for example definitions.

Frame identifier

The bone coordinates to be entered here are read off the x-rays with the help of the generated gridded graphics. The bone segments attached to each fixator ring are described by initial coordinates X1,Z1 and X2,Z2. After deformity correction, the X1,Z1 points will be brought into contact and all the points will lie on a straight line.

Frontal view:

Ring 1: X1 Z1      X2 Z2

Ring 2: X1 Z1      X2 Z2

Lateral view:

Ring 1: X1 Z1      X2 Z2

Ring 2: X1 Z1      X2 Z2

The final deformity parameter which must be provided is the required axial rotation of the frame about the z axis in degrees. THIS IS NOT YET USED.

Axial view:

Z rotation