Positioning Evaluation of Corrective Osteotomy for the Malunited Radius: 3-D CT Versus 2-D Radiographs

Abstract

The authors retrospectively investigated the postoperative position of the distal radius after a corrective osteotomy using 2-dimensional (2-D) and 3-dimensional (3-D) imaging techniques to determine whether malposition correlates with clinical outcome. Twenty-five patients who underwent a corrective osteotomy were available for follow-up. The residual positioning errors of the distal end were determined retrospectively using standard 2-D radiographs and 3-D computed tomography evaluations based on a scan of both forearms, with the contralateral healthy radius serving as reference. For 3-D analysis, use of an anatomical coordinate system for each reference bone allowed the authors to express the residual malalignment parameters in displacements (Δx, Δy, Δz) and rotations (Δφx, Δφy, Δφz) for aligning the affected bone in a standardized way with the corresponding reference bone. The authors investigated possible correlations between malalignment parameters and clinical outcome using patients' questionnaires. Two-dimensional radiographic evaluation showed a radial inclination of 24.9°±6.8°, a palmar tilt of 4.5°±8.6°, and an ulnar variance of 0.8±1.7 mm. With 3-D analysis, residual displacements were 2.6±3 (Δx), 2.4±3 (Δy), and -2.2±4 (Δz) mm. Residual rotations were -6.2°±10° (Δφx), 0.3°±7° (Δφy), and -5.1°±10° (Δφz). The large standard deviation is indicative of persistent malalignment in individual cases. Statistically significant correlations were found between 3-D rotational deficits and clinical outcome but not between 2-D evaluation parameters. Considerable residual malalignments and statistically significant correlations between malalignment parameters and clinical outcome confirm the need for better positioning techniques.

Patient-specific distal radius locking plate for fixation and accurate 3D positioning in corrective osteotomy

“…Positioning is then achieved by subjectively bending a standard plate and subsequent screw fixation. This method has shown to be inaccurate [ 1 ] with residual translation and angulation errors up to 10 mm and 25°. Anatomical plates are assumed to fit the natural bone anatomy.…”

“…Moreover, anatomical plates generally do not follow the geometry of a deformed bone [ 10 ]. Accurate realignment of bone segments is nevertheless of the utmost importance since a statistically significant relationship has been shown between malpositioning and clinical outcome [ 1 ].…”

“…Malunion following a distal radius fracture is a common complication treated by osteotomy surgery. Accurate reconstruction is important since a statistically significant relationship has been found between malpositioning and clinical outcome [ 1 ]. It has been shown that standard anatomical plates may lead to considerable positioning errors in individual patients [ 2 ].…”

Comparing of the reduction accuracy of marker-3D measurement method and traditional radiograph measurement method in the treatment of patients with tibia fracture treated with Taylor Spatial Frame: a retrospective study

“…However, when using an external xator, deformity parameters need to be manually measured on radiographs, which may contain measurement errors [11,12]. Radiographs cannot obtain accurate information about the limb's axial view: deformity parameters related to the rotation has to be estimated by physical examinations [13].…”

Computer-assisted extra-articular distal radius osteotomies using patient-specific surgical guides

“…However, complex bone deformities can often be difficult to identify as these measures are not completely addressed by conventional preoperative planning techniques. At the same time, accuracy of the anatomical reconstruction is essential to achieving optimal functional results [3].…”