A Cadaveric Study on the Accuracy of an Individualized Guiding Template to Assist Scaphoid Fixation Using Computed Tomography and 3-Dimensional Printing

Abstract

The aim of this study was to evaluate the feasibility and accuracy of scaphoid screw guidewire placement using a computer-assisted-designed, and 3-dimensional-printed, surgicalguiding template in cadaver wrists. Computed tomography (CT) scans of 12 fresh-frozen cadaver wrists were performed and the data imported into a surgical planning system. A 3-dimensional skin surface template block with a guiding hole was generated from the CT data to allow a screw guidewire to be placed in thecentral third of the scaphoid. This 3-dimensional model was printed and then put back onto thewrist. A screw guidewire was inserted through the palmar guide hole into the intact scaphoid and then a postprocedure CT scan was obtained. These postprocedure data were introduced into the surgical planning system. Angular and linear deviation between the preprocedural simulation and the image of the guidewire was measured in the system to assess accuracy. Mean angular deviation was 3.85° ± 1.32° (range, 1.56°-5.35°) and linear deviations of the 12 specimens were less than 1.1 mm. No specimen required a repeat drilling to the scaphoid. All the screw guidewires were considered to be centrally placed in the scaphoid based on our criterion of central placement of the scaphoid screw. The use of a computer-assisted 3-dimensional-printed surgical guide template to assist screw guidewire placement into an intact scaphoid, mimicking a nondisplaced scaphoid fracture, showed acceptable accuracy in cadaver wrists. Our technique may provide a simple and effective method for the guidance ofscrew guidewire insertion in a nondisplaced scaphoid fracture surgery.