Computerised Tomographic Analysis of Differences in Scaphoid Trabecular Density in the Intact Bone.

Background: Percutaneous screw placement can treat nondisplaced or scaphoid waist fractures. Screws positioned in areas of highest trabecular density improve fracture stability and bone healing. This study aims to compare the density of six segments of the intact scaphoid bone to facilitate optimal screw positioning. Methods: This study compared the density of six segments of the scaphoid bone in 214 intact scans using the 3D Quantitative Imaging (3DQI) Platform. The scaphoid was divided into proximal, middle and distal regions, each with radial and ulnar segments. Densities were measured in Hounsfield units (HU) and compared using a mixed effects model. Results: The proximal pole had the highest density (proximal radial 551 ± 115 HU; proximal ulnar 546 ± 116 HU), followed by the middle, with the distal pole having the lowest density. The proximal segments were significantly denser than the middle and distal segments. Conclusion: Our study suggests a more ulnar starting point in the distal pole for retrograde percutaneous screw placement, to maximise engagement of the highest trabecular bone density. For the antegrade approach, the proximal pole demonstrates consistently uniform density, permitting screw placement based on fracture plane; however, if possible, the ulnar segment of the distal pole should be engaged.