A Patient-Specific Three-Dimensional-Printed Surgical Guide for Dorsal Scaphoid Fracture Fixation: A Comparative Cadaver Study.

PURPOSE: This study proposes a patient-specific three-dimensional (3D)-printed surgical guide designed for scaphoid fracture fixation through a limited dorsal approach.

METHODS

Computed tomography scans of five cadaveric wrists were modeled in 3D segmentation software and cannulated screw guidewire trajectory was planned. Custom 3D-printed surgical guides for guidewire insertion were designed for each scaphoid. Guidewire placement was performed with and without the surgical guide through a dorsal approach. Postoperative scans were overlaid with the planned trajectory and compared. Five variables were measured: angular deviation, distance between entry points, distance between exit points, embedded guidewire length, and number of attempts.

RESULTS

Mean angular deviation from the planned trajectory was 10.80 ± 6.72° for the guided and 14.08 ± 4.65° for the freehand group. The offset between entry and exit for the guided group was 2.22 ± 1.04 and 3.52 ± 2.80 mm and for the freehand group 2.95 ± 1.31 and 4.91 ± 2.37 mm, respectively. The mean length for the guided group was 23.25 ± 3.33 mm and 23.31 ± 3.07 mm for the freehand group. All guided cases took one attempt and the freehanded cases 2.0 ± 1.0 attempts. A significant positive correlation was found between trajectory and exit. No significance between groups was found between any of the measured variables. A minimum sample size of 28 was determined for follow-up studies.

CONCLUSIONS

The use of a custom surgical guide improved guidewire placement in four of five specimens when compared with a freehand approach. Specifically, the trajectory was closer to the planned trajectory. All guidewire placements were clinically acceptable. Therefore, we consider the use of this surgical guide for the dorsal approach feasible to be used in clinical practice.

CLINICAL RELEVANCE: This device could be used to treat nondisplaced scaphoid fractures. The use of a custom surgical guide could allow for accurate and efficient screw placement as well as reduced operating time and fluoroscopy exposure.