Use of Hausdorff Distance and Computer Modelling to Evaluate Virtual Surgical Plans with Three-Dimensional Printed Guides against Freehand Techniques for Navicular Bone Repair in Equine Orthopaedics.

This research focuses on assessing the precision of virtual surgical plans (VSP) with 3D printed guides against traditional freehand surgical approaches for repairing the navicular bone in horses. The study utilized Hausdorff distance (HD) as a means of evaluation and computer modeling for the execution of an automated computer-based analysis.

Methodology

• Eight pairs of adult horse cadaveric forelimb specimens were applied in an experimental set-up with computer modeling.
• Each limb was subjected to the insertion of a 3.5 mm cortical screw via either a VSP or an aiming device.
• The researchers used computed tomography and computer segmentation for comparing the pre-planned and the implemented screws by applying the Hausdorff distance measurement.

Results

• The mean HD registration error for Navicular bone was -0.06 ± 0.29 mm.
• VSP with 3D printing demonstrated significantly superior accuracy with a mean deviation of 1.19 ± 0.42 mm against the aiming device group (3.53 ± 1.24 mm).
• There was a five times higher probability for the VSP group to result in a mean aberration of less than 1.0 mm.
• A 3.5 mm screw, with an optimal entry point, can have a maximum deviation angle of 3.23 ± 0.07, 2.70 ± 0.06 and 2.37 ± 0.10 degrees in a proximal, dorsal, and palmar direction respectively, before breaching any of the cortical surfaces.

Conclusions

• According to the study, procedures performed using the 3D guides assure a high degree of accuracy, with deviations lesser than 1 mm and 1 degree when compared to the conventional aiming device.
• The research concluded that the use of VSP and the HD as evaluation methods could potentially improve orthopaedic surgical accuracy and simplify the outcome measurement methods.