What professional planning software should actually do
In 2D templating, calibration establishes the relationship between image pixels and real millimeters. Because radiographs are projection images, a marker positioned far in front of or behind the target anatomy may have a different magnification than the bone being planned.
OrthoMetiQ provides a procedure-specific radiology guide because reliable templating starts before the image reaches the planning software.
Questions the workflow must answer
- Is the exact real marker diameter known?
- Is the complete marker visible without clipping or overlap?
- Is it positioned close to the depth plane of the relevant joint?
- Does the projection show the required anatomy without avoidable rotation?
- Has the calibrated scale been checked for plausibility before templating?
A traceable planning workflow
- 01
Select the marker
Use a clearly identifiable marker with a documented real diameter.
- 02
Place at joint depth
Position it near the anatomical depth plane of the hip, knee, ankle or shoulder being planned.
- 03
Acquire the correct projection
Follow the required AP, lateral or weight-bearing protocol and include all necessary anatomy.
- 04
Inspect before export
Confirm marker visibility, absence of clipping and correct laterality.
- 05
Calibrate in software
Enter or confirm the marker diameter and visually inspect scale plausibility.
- 06
Reject unsuitable data
Repeat acquisition when depth error, marker clipping or projection error would make the plan unreliable.
Useful planning outputs
- Known marker dimension
- Reproducible pixel-to-millimeter scale
- Usable image for templating
- Documented acquisition quality
- Lower risk of systematic sizing error
Typical quality limits
- Marker taped to the detector instead of placed at patient/joint depth
- Marker hidden by anatomy or clothing
- Marker partly outside the image
- Wrong documented diameter
- Using a calibration from one image for a separately acquired image
Frequently asked questions
Where should the calibration ball be placed?
As close as possible to the depth plane of the joint or bone segment being planned. A large anterior or posterior offset creates magnification error.
Which marker size should be used?
The software needs the exact real diameter of the visible marker. A 25 mm ball is common, but the documented actual diameter is what matters.
What happens if the marker is misplaced?
Scaling may be systematically incorrect. Measurements and predicted component sizes become unreliable even when the overlay looks plausible.
Can templating be performed without a marker?
Only when another reliable scaling source exists and the workflow is designed for it. For conventional 2D radiographic templating, a correctly placed marker is the safest basis.