Comparison of three dimensional and radiographic measurements in the analysis of distal radius malunion

Abstract

To estimate the accuracy of radiographic deformity evaluation for distal radius malunion, we compared the results obtained from radiographic measurements (palmar tilt, radial angle, and ulnar variance) with those from the three-dimensional (3D) method using computer bone models in 20 dorsally tilted malunions. Dorsal tilt deformity, radial tilt deformity, and shortening deformity were calculated using the unaffected side as a reference. The 3D method showed a slightly lower value for dorsal tilt deformity than the radiographic evaluation, but the difference was < 10° in all cases. In patients with dorsal tilt ≥ 40°, notable differences in radial tilt evaluation were observed between the two methods compared with patients with less dorsal tilt. The 3D shortening showed positive correlations with radiographic evaluation, but a discrepancy of ≥ 2 mm was observed in eight cases. Palmar tilt is reliable for surgical planning, but radial angle and ulnar variance may be less accurate than previously thought.

Postoperative accuracy analysis of three-dimensional corrective osteotomy for cubitus varus deformity with a custom-made surgical guide based on computer simulation

“…29,40 The difference between the preoperative computer simulation and the postoperative result was calculated with 6 of freedom based on the local coordinate system by the Euler angle method. 20,21,33 The intraobserver and interobserver reliabilities of this evaluation technique were demonstrated to be very high, at 0.90 to 0.98 and 0.92 to 0.96, respectively, in the previous study. 33…”

Three‐Dimensional In Vivo Analysis of Malunited Distal Radius Fractures With Restricted Forearm Rotation

“…3D deformity was evaluated by superimposing the proximal part of the affected radius onto the corresponding part of the contralateral (mirror image) unaffected radius with a surface‐based registration technique using another commercial computer software (Bone Simulator; Orthree Co., Ltd). Then, the distal parts of the two radii were superimposed; the extent of 3D deformity of the radius was calculated based on the displacement amount (Fig. A and B).…”

“…Thus, rotation around Z , Y , and X axes, respectively, indicated the dorsal (+) and volar (−) angular deformity, internal (+) and external (−) rotational deformity, and radial deviation (+) and ulnar deviation (−) deformity. We computed the angular deformity using the Euler angles method in which the three computed Euler angles corresponded to the dorsal–volar, internal–external rotation, and radial–ulnar deviation deformities . Because the shortening of the radius is related to forearm rotational restriction, we assessed radial shortening relative to the ulna as ulnar variance (UV) at the supination position.…”

Kahnbeinpseudarthrose: computerassistierte virtuelle Planung der Rekonstruktion

“…Nahezu bis zur letzten Jahrhundertwende beschränkte sich die bildgebende Diagnostik auf konventionelle Röntgenbilder. Naturgemäß ist diese Technologie mit projektionsbedingten Verzerrungen von Winkeln und Längen behaftet [14]. Eine zusätzliche Schwierigkeit bei der Bildgebung kommt durch die diagonale Orientierung des Skaphoids im Raum zustande.…”