This calculator adjusts a measured TT-TG for variations in axial scan plane tilt about the antero-posterior axis of the patient, or alternatively, for excessive relative femoral abduction (or adduction).
- Note: entering a POSITIVE angle of abduction implies GREATER desired relative femoral abduction. To adjust for excessive femoral abduction, enter a NEGATIVE abduction angle.
- The correction is based on a simplified model that neglects the effects of variant femoral rotation, and the antero-posterior offset of the TT from the TG.