Back to Annual Meeting Posters

Introduction: A retrospective, descriptive study to determine the average pertinent measurements of the living human scaphoid waist by analyzing CT images. This will be used in future research to help reconstruct the scaphoid waist after injury. Scaphoid bone fractures account for 69% of all carpal injuries; 65% involve the scaphoid “waist.” Five to 25% result in nonunion requiring surgical intervention and bone grafting to prevent bone collapse, distal pole rotation, apex-dorsal humpback deformity, and eventual radiocarpal arthrosis.  Anthropometric norms are often used in pre-surgical planning for guidance regarding the required bone graft size, shape, and placement.  Published norms for the scaphoid bone are scarce and derived from cadaveric studies.  No anthropometric scaphoid waist norms exist in the literature derived from living subjects.

Methods: All existing CT images of the wrist, over the past 4 years at a single institution, were obtained. All studies from males and females aged 18-65, without injury at the scaphoid, were included to create a sample size of 50 patients. The images were reviewed and analyzed using a novel three-dimensional imaging software; anthropometric data was gathered, to include the scaphoid waist diameter in two dimensions and the scaphoid waist volume. Inter- and intraobserver reliability was ensured by having three physicians familiar with the imaging program separately obtain 2 sets of measurements on each patient; the values were then averaged between the two groups, males and females.

Results: The average measurements of the scaphoid waist in the sagittal plane were 1.164 +/-0.2, in the coronal plane 0.866 +/-0.11, and the waist volume 0.76 +/- 0.24.

Discussion and Conclusion: Measuring CT images of the living human scaphoid waist, using a 3-dimensional imaging program, produced data that can further be used to help approximate the normal scaphoid anatomy for repair after injury.