Assessment of Scaphoid Screw Centrality Using a Dedicated Axial Fluoroscopic View: A CT-Validated Study

Accurate intraoperative assessment of scaphoid screw position is limited by complex anatomy and standard fluoroscopic imaging. The surgical goal is near-central placement within a narrow corridor rather than a single geometric center. This study evaluates a dedicated axial fluoroscopic view for intraoperative assessment of screw centrality.

A retrospective study included 54 patients who underwent scaphoid fixation with intraoperative fluoroscopy, including a dedicated axial view, and postoperative computed tomography (CT). Screw deviation from the geometric center of the scaphoid waist was measured on CT and compared with axial view measurements. Agreement was assessed using Spearman correlation and Bland-Altman analysis. Subgroup analyses were performed based on fracture characteristics.

Mean screw deviation was 1.73 ± 1.07 mm on CT and 1.25 ± 0.73 mm on the axial view. The mean absolute difference was 0.82 ± 0.99 mm. The axial view showed modest correlation with CT and a small systematic underestimation (mean bias -0.47 ± 1.20 mm), with wide 95% limits of agreement (-2.82 to 1.87 mm). Individual axial-view measurements should not be interpreted as interchangeable with CT. Displaced fractures demonstrated greater deviation on the axial view. Union was achieved in 93% of cases using a CT-based definition of osseous bridging.

The axial fluoroscopic view provides additional intraoperative information for assessing scaphoid screw position. Its value lies in detecting relative eccentricity at the guidewire or screw stage rather than replicating CT measurements. This technique may help surgeons judge case-specific acceptability of guidewire trajectory and reduce unrecognized malposition.