Three-dimensional Printed Guides for Screw Placement in Equine Navicular Bones

Objective: To determine the influence of a custom 3D-printed guide for placement of cortical bone screws in the equine navicular bone.

Study Design: Ex vivo study.

Sample Population: Eight pairs of normal adult equine forelimbs.

Methods: A 3.5 × 55 mm cortical screw was placed in the longitudinal axis of each intact navicular bone. Screws were placed with a 3D-printed guide (3D) in one bone and with a traditional aiming device (AD) in the contralateral bone within each pair. Duration of surgery and the number of fluoroscopy images were compared between techniques. Screw placement was subjectively evaluated by gross examination and scored by three boarded veterinary surgeons.

Results: The use of a 3D-printed guide reduced the duration of surgery by 6.6 min (±1.5 min) compared to traditional screw placement (20.7 min ± 4.8 min, p < .01). Fewer peri-operative fluoroscopic images were obtained when the 3D guide was used (18 images ± 2.6 images vs. 40 images ± 5.1, p < .01). No difference was detected in navicular screw placement.

Conclusion: The use of a 3D guide decreased the time required to place screws and the number of intraoperative images taken without affecting screw placement in intact navicular bones.

Clinical Relevance: 3D-printed guides can aid in the study, practice, and execution of surgical procedures reducing surgical time and radiation exposure throughout the operative period achieving similar results to those obtained with a conventional approach.