Validation of an automatic three-dimensional method for distal radius measurements and malunion quantification.

Preoperative CT measurements of distal radial inclination and volar tilt are useful for surgical planning, but current methods are time-consuming and user-dependent. This study validates an automated 3D measurement method for these measurements. We analysed 20 bilateral CT scans, including healthy and pathological sides with extra-articular malunions. Three senior observers performed manual measurements and an automated algorithm generated measurements based on the radiocarpal surface. Agreement between manual and automatic methods was evaluated using concordance correlation coefficients and Bland-Altman analysis, with acceptable agreement set at 5° for the coefficient of repeatability. Correction quantification accuracy was assessed by comparing each method to a reference method. The mean difference in radial inclination between the automatic and manual methods was -6° and for volar tilt was -2.6°. The automated method showed closer correction agreement with the reference, enhancing reproducibility and saving time in preoperative planning.Level of evidence: III.