Computed Tomography and Fluoroscopy versus Radiographic Guidance for Internal Fixation of Central Tarsal Bone Fractures in Nonracing Horses

Introduction: Internal fixation of central tarsal bone (CTB) fractures is challenging due to the size and curvature of the CTB. CT-imaging can improve the understanding of fracture configuration and precision of screw placement but may not be available to every surgeon. This study assessed screw placement in simulated dorsomedial-plantarolateral CTB fractures in 10 pairs of cadaver tarsi using two guidance techniques. We hypothesized that CT with fluoroscopy would be superior to radiography in procedure time and precision of screw placement.

Materials and Methods: A 4.5 mm screw was placed using either CT and fluoroscopy or radiography alone, followed by postoperative CT. Variables related to marker placement, procedure time, and screw positioning were recorded and compared using a matched pairs t-test for dependent means (p < 0.05).

Results: Preoperative CT resulted in a longer time for marker placement (p = 0.004) with no difference in total procedure time between groups (p = 0.10). There was no difference (p > 0.05) between groups for screw angle, articular surface interference, screw length, or proximal-to-distal screw position. Selection of screw length was more variable using radiography.

Discussion/Conclusion: Internal fixation of dorsomedial-plantarolateral CTB fractures can be performed using either technique; however, mild adjustments in fluoroscopic or radiographic angle can dramatically alter the perception of screw placement. The CTB curvature prevented the screw from being centered within the CTB along its entire length.

Acknowledgments: The authors have no proprietary interests to declare. This study was funded by the American College of Veterinary Surgeons Foundation Diplomate Research Grant.

Publication History

Article published online:
11 September 2023