Assessment of Usefulness of Anthropometric Data for Predicting the Scaphoid and the Screw Length: A New Technique.

BACKGROUND: Headless screw is frequently used for scaphoid fracture fixation. Aim of the study was to assess the correlation between the axial length of the scaphoid and the axial length of the middle phalanx of index, middle, ring and little finger so as to provide an indirect method to assess the length of the scaphoid and thereby the length of the screw. METHODS: Thirty five fresh frozen cadavers with seventy wrists and hands were dissected. The age, sex and side were recorded. The axial length of the scaphoid, axial length of the middle phalanx of index, middle, ring and little finger were recorded and a correlation was assessed. Five cadavers were randomly selected and radiographs of the hand were done. Pearson coefficient correlation was assessed between the axial length of the middle phalanx of ring finger on a radiograph and actual length of middle phalanx. RESULTS: A significant positive correlation was noted between the axial length of the scaphoid and the axial length of the middle phalanx of ring finger (r = 0.646), also a positive correlation between the axial length of middle phalanx of ring finger on a radiograph and the axial length of the scaphoid measured by vernier caliper (r = 0.91). CONCLUSIONS: A preoperative radiograph of the wrist with hand will help us indirectly assess the axial length of the scaphoid by measuring the axial length of the middle phalanx of ring finger.