Comparison of two different screw trajectories in the treatment of oblique scaphoid fractures: A mechanical study on composite bone models

Abstract

Objectives: In this mechanical study, we aimed to comparetwo different screw trajectories in terms of durability againstaxial loads on oblique scaphoid fractures using composite bonemodels.Materials and methods: Oblique osteotomies were madealong the dorsal sulcus of 14 composite scaphoid bone models.Following this, all bone models were randomly classified. Onegroup of bones were fixed with a screw placed perpendicular tothe osteotomy line and the other group was fixed with a screwplaced centrally down the long axis of the scaphoid bone. Eachscaphoid bone model was positioned on a mechanical testingmachine. Subsequently, axial loading tests were applied oneach bone model to measure the amount of loading requiredto cause 2-mm displacement and failure on the osteotomy sideand maximum displacement at the time of failure on scaphoidbone models.Results: There was no statistically significant difference inload to 2-mm displacement and failure between the two groups(p>0.05). Also, there was no statistically significant differencebetween the two groups in terms of maximum displacement seenon failure (p>0.05).Conclusion: In our study, we found that the stability of thescrews which laid perpendicular to the fracture line and parallelto the long axis of the scaphoid was the same in fixing obliquescaphoid fractures.