The Spiral Fracture with Butterfly Fragment
This X-ray on the antero-posterior (A-P) projection shows a comminuted spiral fracture of the distal shaft of the fibula in a 26 year old male. Image b shows the fracture as best depicted in a single projection with black overlay, while image c reveals three fragments with the lightest turquoise green overlaying the triangular or butterfly fragment. The mechanism of this injury is usually a twisting or torsional injury. The interosseus membrane also acts as a resisting force and may account for the butterfly fragment
Courtesy Ashley Davidoff Copyright 2011 101075b06L.81c
The Common Vein Copyright 2011
Introduction
When a pressure is applied to a long bone at an approximate right angle vector a pliable structure like bone will bend having a concave shape on the receiving end of the force and a convex shape on the opposite surface
The forces on the concave side are compressive and on the opposite convexity they are tensile.(Latin tendere – to stretch).
Compressive and Tensile Forces
The series of images show the initial force on the bone (large red arrow in a) followed by the compressive force (small red arrows b) on the ipsilateral side of the injurious force. As the force gets transmitted through the bone tensile forces (white arrows in c) cause a distraction of the fibres of the bone.. When a pressure is applied to a long bone at an approximate right angle vector a pliable structure like bone will bend having a concave shape on the receiving end of the force and a convex shape on the opposite surface The forces on the concave side are compressive and on the opposite convexity they are tensile.(Latin tendere – to stretch).
Courtesy Ashley Davidoff Copyright 2011 106647p.84cL.91L
The Difference Between Fractures of Pediatric and Adult Bone
This set of X-rays in the antero-posterior (A-P) projection shows the difference of the effect of a lateral force on the mid shafts of a pliable pediatric radius and ulna (a) and on the more brittle mature bones of a 19 year patient (b). In the pediatric bones they respond to the force by a bowing deformity without obvious macrofracture. This is a type of greenstick fracture. In the adult the bone shows transverse fracture of the radius and ulna.
Courtesy Ashley Davidoff Copyright 2011 101293.8bc01
The Spiral Fracture with Butterfly Fragment
This X-ray on the antero-posterior (A-P) projection shows a comminuted spiral fracture of the distal shaft of the fibula in a 26 year old male. Image b shows the fracture as best depicted in a single projection with black overlay, while image c reveals three fragments with the lightest turquoise green overlaying the triangular or butterfly fragment. The mechanism of this injury is usually a twisting or torsional injury. The interosseous membrane also acts as a resisting force and may account for the butterfly fragment
Courtesy Ashley Davidoff Copyright 2011 101075b06L.81c