1. Morphometric Variations of Scaphoid and Safety of Screw Fixation for Its Waist Zone Fractures in Indian Population: A Preliminary Report 
Vivek Trikha, MS, Arvind Kumar, MS, Samarth Mittal, MS, Jigyasa Passey, MS, Sahil Gaba, MS, Rizwan Khan, DO, Aditya Jain, MS, Atin Kumar, MD 
Journal of Hand Surgery Global Online 
Volume 1, Issue 3, Pages (July 2019)
DOI: /j.jhsg
Copyright © 2019 The Authors Terms and Conditions

2. Figure 1
A The medial articular surface of the scaphoid waist region was aligned in the same vertical plane in an axial cut, B the proximal-most and distal-most extents of medial articular surfaces were placed along a single vertical line in a coronal section, and C the volar-most extents of the proximal and distal segments were kept in a single horizontal plane in the sagittal section.
Journal of Hand Surgery Global Online 2019 1, DOI: ( /j.jhsg )
Copyright © 2019 The Authors Terms and Conditions

3. Figure 2
A, B Coronal widths of the proximal, waist, and distal segments were measured as maximal mediolateral extents of the scaphoid from the medial articular surface to the outermost surface in the defined zones directed perpendicular to the medial articular surface. C Sagittal measurements for these zones were taken as maximal vertical extents at the waist constriction region and proximal and distal to it.
Journal of Hand Surgery Global Online 2019 1, DOI: ( /j.jhsg )
Copyright © 2019 The Authors Terms and Conditions

4. Figure 3
The scaphoid curvature angle was measured as the angle between the lines joining the proximal-most (a) and distal-most (b) extents of the medial articular surface to a point falling most lateral on it (c), after aligning the former 2 points in the same vertical line.
Journal of Hand Surgery Global Online 2019 1, DOI: ( /j.jhsg )
Copyright © 2019 The Authors Terms and Conditions

5. Figure 4
Placement of a single central cylindrical trajectory directed perpendicular to the narrow zone of waist. The diameter of the cylindrical trajectory includes the screw diameter and an additional safety corridor of 2 mm (1 mm on each side of the screw diameter). The trajectory shown here lies well within the bony limits of the narrow zone of the waist in different sections.
Journal of Hand Surgery Global Online 2019 1, DOI: ( /j.jhsg )
Copyright © 2019 The Authors Terms and Conditions

6. Figure 5
Placement of 2 parallel cylindrical trajectories of different diameter screws coplanar in the coronal plane, directed perpendicular to the narrow zone of the waist. The trajectories include the safety corridor of 2 mm (1 mm on each side of the screw diameter). The trajectories shown here lie well within the bony limits of the waist in different planes.
Journal of Hand Surgery Global Online 2019 1, DOI: ( /j.jhsg )
Copyright © 2019 The Authors Terms and Conditions

7. Figure 6
Placement of 2 parallel cylindrical trajectories coplanar in the sagittal plane, directed perpendicular to the narrow zone of the waist. The trajectories shown here, which include the screw diameter with an additional safety corridor of 2 mm (1 mm on each side of the screw diameter), lie well within the bony limits of the waist in different planes.
Journal of Hand Surgery Global Online 2019 1, DOI: ( /j.jhsg )
Copyright © 2019 The Authors Terms and Conditions

8. Figure 7
Because of the curved anatomy of the scaphoid, its maximal bony extent (yellow) will always differ from the length of a screw placed centrally (blue) in the waist region. As seen in the image, some region of the proximal segment remains unused by the screw. This region may differ among subjects, depending on scaphoid curvature.
Journal of Hand Surgery Global Online 2019 1, DOI: ( /j.jhsg )
Copyright © 2019 The Authors Terms and Conditions