gms | German Medical Science

Objectives/Interrogation: To reproduce anatomical reduction and appropriate implant placement during the osteosynthesis, image fusion system for the 3D preoperative planning and the fluoroscopy was developed. The objective of this study was to assess the utility of image fusion system by evaluating the reproducibility of preoperative plan in the osteosynthesis of distal radius fractures.

Methods: Twenty-eight wrists of 28 distal radius fracture patients who underwent osteosynthesis using volar locking plates (22 females, 6 males, mean age 62.2 years) were evaluated. The patients were divided into two groups. The image fusion group (n=14) utilized 3D preoperative planning and image fusion system. The control group (n=14) utilized only 3D preoperative planning. The age, sex, and fracture types were matched between groups. All patients had pre- and post-operative CT scans to evaluate the reproducibility of preoperative plan. In both groups, 3D preoperative planning were performed in order to determine the reduction, placement and choices of implants. In the image fusion group, the outline of the planned image was displayed on the monitor overlapping with fluoroscopy image during surgery. Surgeons performed osteosynthesis with the fusion image. Reductions were evaluated by the volar tilt and radial inclination of the 3D images. Plate positions were evaluated with the distance between distal edge of the plate and the distal radius articular surface, and the positions of plate axis relative to the radius axis. Screw choices were recorded for the plan and actual choices for each screw hole. The reproducibility were evaluated by the difference of the parameters between pre- and post-operative image. The differences for reduction shape, plate positions, and screw choices were compared between groups.

Results and Conclusions: The difference of the distance between plate and articular surface were significantly smaller in the image fusion group compared to the control group (0.30+/-0.29 mm and 0.81+/-0.59 mm for image fusion and control groups, respectively, P<0.01). The difference of the distal screw choices were significantly smaller in the image fusion group compared to the control group (0.32+/-0.64mm and 0.64+/-0.92 mm for image fusion and control groups, respectively, P<0.01). There were no significant differences in the reduction shape and the plate axis position. The image fusion system was useful to reproduce the planned plate position and distal screw choices in the osteosynthesis of distal radius fractures.